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Philips, Julia Rachel. "B-1 and B-2 B cell responses to lipopolysaccharide: Putative roles in the pathogenesis of periodontitis." Thesis, The University of Sydney, 2003. http://hdl.handle.net/2123/1852.

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Periodontal disease is one of the most widespread diseases in humans and is characterised by chronic gingival inflammation and B cell accumulation and resorption of the crest of alveolar bone with subsequent loss of teeth. Porphyromonas gingivalis has been identified as a putative aetiological agent for periodontitis. The aim of the research presented in this thesis was to investigate, using in vitro systems, the responses of autoreactive B-1 and B-2 cells to enterobacterial and nonenterobacterial lipopolysaccharide (LPS) to shed light on the pathogenesis of chronic periodontitis and other diseases involving B cell accumulation and autoantibody production. The hypotheses tested were: (1) B cells respond differently to enterobacterial and non-enterobacterial LPS. (2) B-1 cells are activated by a lower concentration of LPS than B-2 cells. (3) LPS stimulation results in preferential accumulation of B-1 cells. Findings consistent with these hypotheses would provide new evidence for different roles for B-1 and B-2 cells in immune responses and that LPS stimulation could lead to B-1 cell accumulation in diseases thus characterised. Initial experiments investigated the responses of representative B-1 (CH12) and B-2 (WEHI-279) cell lines to preparations of P. gingivalis and Salmonella enteritidis LPS utilising flow cytometric and quantitative molecular methods. The cell lines responded differently to the two LPS preparations. There were significant but limited effects on viability and proliferation in the WEHI-279 cell line, but no significant changes in mRNA expression levels for genes including Toll-like receptors (TLR2, TLR4, RP105), immunoglobulin (IgM), cytokines (IL-6, IL-10), co-stimulatory molecules (CD80, CD86), and regulators of apoptosis (Bcl-2, Bax). In the CH12 cell line however, LPS stimulation had greater effect. Addition of S. enteritidis LPS from a threshold level of 100ng/mL was found to rescue the cells from death, reflected by the percentage viability and proliferation. Stimulation of CH12 cells with S. enteritidis LPS also led to a decrease in expression of RP105 mRNA, which may be part of a negative feedback loop. Interestingly, stimulation with low concentrations P. gingivalis LPS appeared to inhibit proliferation but high LPS concentrations stimulated proliferation of CH12 cells, although no further significant effects were noted in other analyses. Evidence was found that CH12 cells have a high basal level of activation. This suggests that this line is constitutively activated. Stimulation with P. gingivalis or S. enteritidis LPS did not affect the level of CD80 mRNA expression. It is possible that the CH12 line constitutively expresses a maximal level of CD80 (and possibly CD86) and further stimulation will not cause any increase. Since S. enteritidis LPS appeared to have more pronounced effects on both B cell populations, this LPS was used to further investigate B cell subset responses in a mixed splenocyte culture system. Experiments examining percentage viability and number of viable cells indicated that B-1 and B-2 B cells responded differently to LPS stimulation. A threshold level for B-2 cell response (significant increase in cell number) was found to be 100ng/mL LPS, in contrast to the B-1 B cell subset which were only significantly different to the unstimulated cells when stimulated with 50μg/mL LPS. By examining the expression of CD80, the majority of murine splenic B-1 cells were found to activated prior to any LPS stimulation in vitro. In contrast, the B-2 subset showed significant increase in CD80 expression only at high (≥10μg/mL) LPS concentrations. Studies of the division index of B-1 and B-2 cells showed a significant response in both subsets following stimulation with 1μg/mL and 10μg/mL LPS. However, overall, the results are inconsistent with LPS driving the preferential accumulation of B-1 cells in disease states. These experiments provided useful evidence that supported the idea that B-1 and B-2 cells respond differently to LPS. However, these studies were unable to directly address the role of P. gingivalis LPS in periodontitis. It may be that P. gingivalis LPS could have different effects to S. enteritidis LPS on primary B cells. It is still possible that B-1 cells may be more sensitive to P. gingivalis, as opposed to S. enteritidis LPS. Studies by other groups have suggested that the TH1/TH2 profile is skewed towards TH2 in chronic periodontitis and that P. gingivalis may drive this shift via its ability to signal through TLR2 (and modulate TLR4 signalling). Further, recent studies in our laboratories have found that P. gingivalis gingipains are able to polyclonally activate B cells and to break down both IFNγ and IL-12. Future studies should further examine the effects of B-1 and B-2 interactions in the mixed lymphocyte system together with subsequent studies utilising human periodontitis biopsies. The results presented in this thesis, together with work undertaken by other investigators, suggests that LPS could perturb the normal homeostatic mechanisms of the B-1 B cell-subset and increase polyclonal activation therefore contributing to the genesis of pathologies such as chronic periodontitis.

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Philips, Julia Rachel. "B-1 And B-2 B Cell Responses To Lipopolysaccharide: Putative Roles In The Pathogenesis Of Periodontitis." Thesis, The University of Sydney, 2006. http://hdl.handle.net/2123/4395.

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Master of Science
Periodontal disease is one of the most widespread diseases in humans and is characterised by chronic gingival inflammation and B cell accumulation and resorption of the crest of alveolar bone with subsequent loss of teeth. Porphyromonas gingivalis has been identified as a putative aetiological agent for periodontitis. The aim of the research presented in this thesis was to investigate, using in vitro systems, the responses of autoreactive B-1 and B-2 cells to enterobacterial and nonenterobacterial lipopolysaccharide (LPS) to shed light on the pathogenesis of chronic periodontitis and other diseases involving B cell accumulation and autoantibody production. The hypotheses tested were: (1) B cells respond differently to enterobacterial and non-enterobacterial LPS. (2) B-1 cells are activated by a lower concentration of LPS than B-2 cells. (3) LPS stimulation results in preferential accumulation of B-1 cells. Findings consistent with these hypotheses would provide new evidence for different roles for B-1 and B-2 cells in immune responses and that LPS stimulation could lead to B-1 cell accumulation in diseases thus characterised. Initial experiments investigated the responses of representative B-1 (CH12) and B-2 (WEHI-279) cell lines to preparations of P. gingivalis and Salmonella enteritidis LPS utilising flow cytometric and quantitative molecular methods. The cell lines responded differently to the two LPS preparations. There were significant but limited effects on viability and proliferation in the WEHI-279 cell line, but no significant changes in mRNA expression levels for genes including Toll-like receptors (TLR2, TLR4, RP105), immunoglobulin (IgM), cytokines (IL-6, IL-10), co-stimulatory molecules (CD80, CD86), and regulators of apoptosis (Bcl-2, Bax). In the CH12 cell line however, LPS stimulation had greater effect. Addition of S. enteritidis LPS from a threshold level of 100ng/mL was found to rescue the cells from death, reflected by the percentage viability and proliferation. Stimulation of CH12 cells with S. enteritidis LPS also led to a decrease in expression of RP105 mRNA, which may be part of a negative feedback loop. Interestingly, stimulation with low concentrations P. gingivalis LPS appeared to inhibit proliferation but high LPS concentrations stimulated proliferation of CH12 cells, although no further significant effects were noted in other analyses. Evidence was found that CH12 cells have a high basal level of activation. This suggests that this line is constitutively activated. Stimulation with P. gingivalis or S. enteritidis LPS did not affect the level of CD80 mRNA expression. It is possible that the CH12 line constitutively expresses a maximal level of CD80 (and possibly CD86) and further stimulation will not cause any increase. Since S. enteritidis LPS appeared to have more pronounced effects on both B cell populations, this LPS was used to further investigate B cell subset responses in a mixed splenocyte culture system. Experiments examining percentage viability and number of viable cells indicated that B-1 and B-2 B cells responded differently to LPS stimulation. A threshold level for B-2 cell response (significant increase in cell number) was found to be 100ng/mL LPS, in contrast to the B-1 B cell subset which were only significantly different to the unstimulated cells when stimulated with 50μg/mL LPS. By examining the expression of CD80, the majority of murine splenic B-1 cells were found to activated prior to any LPS stimulation in vitro. In contrast, the B-2 subset showed significant increase in CD80 expression only at high (≥10μg/mL) LPS concentrations. Studies of the division index of B-1 and B-2 cells showed a significant response in both subsets following stimulation with 1μg/mL and 10μg/mL LPS. However, overall, the results are inconsistent with LPS driving the preferential accumulation of B-1 cells in disease states. These experiments provided useful evidence that supported the idea that B-1 and B-2 cells respond differently to LPS. However, these studies were unable to directly address the role of P. gingivalis LPS in periodontitis. It may be that P. gingivalis LPS could have different effects to S. enteritidis LPS on primary B cells. It is still possible that B-1 cells may be more sensitive to P. gingivalis, as opposed to S. enteritidis LPS. Studies by other groups have suggested that the TH1/TH2 profile is skewed towards TH2 in chronic periodontitis and that P. gingivalis may drive this shift via its ability to signal through TLR2 (and modulate TLR4 signalling). Further, recent studies in our laboratories have found that P. gingivalis gingipains are able to polyclonally activate B cells and to break down both IFNγ and IL-12. Future studies should further examine the effects of B-1 and B-2 interactions in the mixed lymphocyte system together with subsequent studies utilising human periodontitis biopsies. The results presented in this thesis, together with work undertaken by other investigators, suggests that LPS could perturb the normal homeostatic mechanisms of the B-1 B cell-subset and increase polyclonal activation therefore contributing to the genesis of pathologies such as chronic periodontitis.

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Philips, Julia Rachel. "B-1 and B-2 B cell responses to lipopolysaccharide putative roles in the pathogenesis of periodontitis /." University of Sydney, 2006. http://hdl.handle.net/2123/1852.

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Chen, Hui-Chen. "Role for cyclic adenosine monophosphate (cAMP) response element binding proteins in B lymphocyte development and functional maturation." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1061213266.

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Thesis (Ph. D.)--Ohio State University, 2003.
Document formatted into pages. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2005 Aug. 19.

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Kazbay, Kasim. "Leu 1+B cells in autoimmune human diseases." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55681.

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Le, Thuc-vy L. "B cell clonal abundance and madcam-1 mediate affinity maturation and fate of germinal center B cells." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2009r/le.pdf.

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Zao, Chih-Ling. "B Virus Circumvents Innate Responses in Human Cells." Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/biology_diss/41.

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B virus (Cercopithecine herpesvirus 1) is an alphaherpesvirus indigenous to macaque monkeys and is closely related to herpes simplex virus type 1 (HSV-1). Disease caused by B virus, which is often mild or asymptomatic in its natural host, the macaque monkey, is similar in infected macaques to HSV-1 infection in humans. When B virus zoonotically infects foreign hosts, e.g., humans, high morbidity and mortality are evidenced in > 80% of untreated cases. To explore the underlying reasons for differences in pathogenesis between B virus and HSV-1 infection in humans, human microarrays were used to comparatively examine global cellular gene expression patterns engaged as a result of infection of human foreskin fibroblasts (HFFs). Our results demonstrate that these closely related simplexvirus family members have divergent strategies to thwart host cell pathways related to innate defenses. In these studies, B virus did not induce detectable interferon, cytokine or chemokine genes, in sharp contrast to HSV-1, which induced innate immune responsive genes in infected cells. Although no innate immune response genes were found to be up-regulated by B virus infection, B virus induced I£eB£a, which was the only gene found to be involved in the NF-£eB signaling pathway within the innate immunity biological network. Quantification of NF-£eB p50 DNA binding activity in virus-infected nuclear extracts demonstrated that NF-£eB p50 DNA binding activity was lower in B virus-infected cells. Suppression of I£eB£a in B virus infected cells by siRNA restored NF-£eB-induced cytokine and chemokine expressions. Data presented here support the model that I£eB£a inhibits NF-£eB regulated immune responsive genes in B virus-infected HFF cells, and this response differs from that observed in HFF cells infected with HSV-1. The result is that B virus alters the NF-£eB regulated expression of cytokine and chemokine genes of HFF cells differently from HSV-1 early after infection. These differences in cytokine and chemokine expression may be associated with the delayed or reduced host responses observed in B virus infected humans and underlie the failure of adaptive responses in zoonotically infected humans.

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Cox, Selwyn Lewis Garvan Institute of Medical Research Faculty of Medicine UNSW. "The role of B cells in type 1 diabetes." Publisher:University of New South Wales. Garvan Institute of Medical Research, 2009. http://handle.unsw.edu.au/1959.4/43789.

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Type 1 Diabetes (T1D) is an autoimmune disease where the immune system destroys the insulin-producing beta cells within the pancreas. Due to the difficulty of obtaining relevant tissue samples from patients at risk of disease, many researchers have utilized the nonobese diabetic (NOD) mouse as a model of T1D due to their natural high susceptibility for this disease which shares many characteristics with human patients. This model has been critical for uncovering many mechanisms involved in the pathogenesis of T1D including the key roles played by autoreactive T cells in the destruction of beta cells. More recently, NOD mice have shown that self-reactive B cells act as important antigen presenting cells for activating and amplifying the T cell response against beta cells. In order to identify faulty self-tolerance mechanisms causing production and activation of B cells recognizing beta cell proteins, we have developed a transgenic mouse model whereby elevated numbers of B cells are made specific for a neo-self antigen whose expression is restricted to beta cells on the T1D-prone NOD genetic background and compared it to that of transgenic mice of the non-autoimmune prone C57BL/6 (B6) genetic background. These studies revealed that NOD and B6 B cells can both be effectively tolerized to the model beta cell-restricted antigen. However, provision of help from activated T cells readily overturned this tolerance on the NOD but not the B6 background. Prior evidence has associated Idd5 (chromosome 1) and Idd9/11 (chromosome 4) diabetes susceptibility loci in NOD mice with the development of self reactive B cells contributing to T1D. The gene encoding CTLA-4 has been identified as the major candidate susceptibility gene within Idd5, thus leading to our studies comparing B cell expression of this molecule in NOD and diabetes-resistant strains. Although almost always associated with down-modulating T cells responses, our studies and that of others confirm expression of CTLA-4 by activated B cells. We encountered B cell expression of CTLA-4 to vary from that of T cells, being expressed earlier and predominantly on the cell surface rather than within intracellular vesicles. Our studies also showed aberrant expression of different splice variants of CTLA-4 by NOD B cells compared to diabetes-resistant mice controlled by genes within and outside the Idd5 genetic locus. Hence, these studies raise the possibility that CTLA-4 may contribute to T1D through its actions on both T and B cells. Given the large nature of the Idd9/11 susceptibility locus in NOD mice and the absence of any strong candidate genes that may influence the diabetogenic capacity of B cells in this strain, we resorted to microarray technology to reveal putative genes within this genomic region with the potential to control the B cell phenotype. We focused our microarray studies on the first transitional (T1) B cell population in the spleen given that it is an important stage of tolerance to peripherally expressed self-antigens which have been found to possess various defects in NOD mice. Comparing gene expression profiles of NOD T1 B cells that expressed susceptibility or resistance alleles at the Idd9/11 locus identified 20 differentially expressed genes with the potential to contribute to development of diabetogenic B cells. Overall, data presented in this thesis provides a greater understanding of the molecular and cellular mechanisms underlying B cell contribution to T1D in NOD mice. These data are hoped to eventually lead to the development of selective strategies for removing or inhibiting only those B cells that contribute to development of T1D while ensuring that humoral immunity to foreign pathogens remains intact in human patients at risk of developing disease.

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Ekici, Rifat. "B cells in Type 1 diabetes : studies on cell surface antibody binding." Licentiate thesis, Umeå universitet, Immunologi/immunkemi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-37376.

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Schneider, Dina. "The role of paired box 5, B lymphocyte-induced maturation protein-1 and activation protein-1 in the suppression of B cell differentiation by 2,3,7,8-tetrachlorodibenzo-p-dioxin." Diss., Connect to online resource - MSU authorized users, 2008.

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Thesis (Ph.D.)--Michigan State University. Dept. of Pharmacology and Toxicology, 2008.
Title from PDF t.p. (viewed on Mar. 30, 2009) Includes bibliographical references (p.157-191). Also issued in print.

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Camargo, Da Rosa Larissa. "Regulatory B cells in an experimental model of type 1 diabetes." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/100517/.

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Regulatory B cells, producing IL-10, have been studied in many autoimmune diseases. However, less is known about these cells in Type 1 diabetes (T1D), a disease characterized by the destruction of beta-cells by the immune system, leading to deficient production of insulin. Although B cells play a role in development of T1D, most previous investigations have focused on their pathogenic involvement. B cell depletion has been shown to be protective against diabetes development. To examine regulatory B cells in T1D, we used Non-Obese Diabetic (NOD) mice and non-diabetes-prone B6g7 mice as controls. We compared both strains for the production of cytokines and expression of putative regulatory phenotypes in spleen B cells cultured with various stimulants, at different ages. We observed that NOD mice that were > 35 weeks old and naturally protected against T1D had more IL-10-producing B cells than B6g7 and diabetic NOD mice, and this number increased even more on stimulation with lipopolysaccharide (LPS) stimulation. When LPS-stimulated B cells from protected mice were cultured in vitro with CD8 T cells and DCs, their potential for suppression of T cell cytotoxic activity was higher than unstimulated B cells and B cells from diabetic mice. This inhibitory effect was associated with higher levels of IL-10. Lastly, we carried out an investigation where B cells were transiently depleted in transgenic NOD mice expressing human CD20, to enable depletion using a human anti-CD20 monoclonal antibody. We evaluated the effect of depletion and repopulation on regulatory B cells, testing whether the protection afforded by B cell depletion was due to a change in regulatory B cell number or function. B cells with putative regulatory phenotypes were susceptible to depletion and, although the treatment with anti-CD20 reduced the incidence and delayed the onset of diabetes, there was no difference in the IL-10 producing B cell population by the time of full repopulation of B cells. Thus, this protective effect of B cell depletion was unlikely to be due to IL-10-producing B cells. In conclusion, for the first time, regulatory B cells were extensively studied in NOD mice and we demonstrated that protected NOD mice had higher frequencies of spleen B cells producing IL-10 than diabetic NOD mice. Further investigation is warranted to understand how these IL-10-producing B cells contribute to protection against type 1 diabetes.

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Fortunati, Jennifer L. "Development of a human plasmacytoma cell line with inducible expression of activated B-cell factor-1." Scholarly Commons, 2004. https://scholarlycommons.pacific.edu/uop_etds/594.

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The basic helix-loop-helix protein, activated B-cell factor-l (ABF-l), is a transcription factor involved in cellular proliferation and differentiation. ABF-1 shows patterns of expression that are stimulated in activated B cells, which may suggest ABF-1 is involved in the regulation of B-cell differentiation. To investigate the functional role of ABF-1, we have generated a human plasmacytoma cell line with inducible expression of ABF-1. We were able to induce expression of ABF-1 by using the tetracycline repressor system (teton/off). With addition of tetracycline we were able to stimulate the expression of the full-length ABF-1 in the cells. We also got induction of the truncated form of ABF-1, lacking the protein dimerization domain (HLH), with the addition of tetracycline. We then compared these two cell lines to uninduced cells. We confirmed that ABF-1 expression was induced by western blot analysis. We conclude that we have developed a human plasmacytoma cell line with inducible expression of ABF-1 and can use this cell line for further studies.

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Richmond, Jennifer Mary. "Development of a Burkitt Lymphoma cell line with inducible expression of activated B-cell factor-1." Scholarly Commons, 2004. https://scholarlycommons.pacific.edu/uop_etds/595.

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Activated B-cell Factor-I (ABF-1) is a class II basic helix-loop-helix protein expressed in activated B-cells, EBV -immortalized lymphoblastoid cell lines and embryonic skeletal muscle in mice. ABF -1 dimerizes with another bHLH protein E4 7 to form a transcriptional repressor ofE2A, which is a gene essential to the proper development of B- and T -cells. In an effort to study genes in B-cells regulated by ABF- 1, I have attempted to construct a Burkitt Lymphoma cell line allowing tetracycline regulated expression of ABF-1. The tetracycline repressor gene was first added to these cells, creating a parental line oftet repression. Next, both a full-length and a truncated version of ABF -1 were added to the cell line. The truncated version of the protein is expressed in the presence of tetracycline, but completely repressed in its absence, demonstrating a tightly-regulated system of inducible expression. The full-length version of ABF-1 has yet to be expressed in this cell line; however, it has been expressed in a HeLa cell line, demonstrating that the construct has been properly made.

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Noal, Vanessa Rosa. "Estudo da interação de linfócitos B-1 com antígenos de Paracoccidioides brasilienses." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-03052010-160726/.

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Diversos dados na literatura têm demonstrado a participação de linfócitos B-1 em diferentes fenômenos imunológicos, tanto na resposta imune inata quanto na resposta imune adaptativa. Para melhor entendermos a ativação da resposta imune eficaz contra fungos patogênicos, pesquisamos a interação entre os linfócitos B-1 e o Paracoccidioides brasiliensis (P. brasiliensis), uma vez que este expressa moléculas antigênicas que podem ser reconhecidas pelo sistema imune. Utilizamos preparação antigênica do P. brasiliensis obtida de sua superfície leveduriforme denominada de CFA (antígeno livre da parede do fungo) e células leveduriforme do fungo. Observou-se que a maioria das células do sobrenadante da cultura celular de 4 dias de células totais aderentes peritoneais eram constituídos por linfócitos B-1; estas células expressam altos níveis de MHC-II (100%) e CD80 (90%). Contudo, não houve expressão significativa da molécula co-estimuladora CD86. Pela análise fenotípica, os linfócitos B-1 podem atuar como células apresentadoras de antígeno pois expressam CD80, CD86 e MHC-II; então realizamos o ensaio de proliferação celular utilizando linfócitos B-1 como células apresentadoras de antígenos e observamos proliferação celular de linfócitos TCD4+ significativa. Em relação às citocinas, analisamos a secreção de IL-10 e TNF-α do sobrenadante da cultura de linfócitos B-1 sem nenhum estímulo e observamos que estas células secretam tanto IL-10 quanto TNF-α; após estímulo de CFA, os valores aumentam significantemente. Analisamos a expressão de TLR-2, TLR-4, MyD88 e IL-10, por RT-PCR, dos linfócitos B-1 na presença de CFA. Encontramos expressão de TLR-2, MyD88 e IL-10 nas células com e sem estímulo. Analisamos a migração dos linfócitos B-1 da cavidade peritoneal de camundongos BALB/c após estímulo intraperitoneal (ip) com leveduras de PB. Decorridas 5 horas, foi observada grande diminuição dos linfócitos B-1 na cavidade peritoneal, que permanecia por 24 horas e 7 dias pós-infecção. Para melhor compreendermos a migração dos linfócitos B-1, foram utilizados camundongos CBA/N Xid (desprovidos de linfócitos B-1), cujo o peritônio foi reconstituído com linfócitos B-1, sendo infectados ip com leveduras de P brasiliensis. Os resultados demonstram que, após a infecção, os linfócitos B-1 migram da cavidade peritoneal para o baço. Também, observou-se aumento no número de células T com fenótipo de célula regulatória (CD4+CD25+Foxp3+). Nossos resultados sugerem que a elevada produção de IL-10 por células B-1, mediada provavelmente pela ligação de TLR-2, juntamente com a capacidade dos linfócitos B-1 em ativar linfócitos T, com a capacidade de migrar do peritônio para o baço e ativar células T regulatórias, poderia favorecer a sobrevivência do fungo no hospedeiro.
Innumerous data published in the literature have shown the involvement of B-1 cells in different immunological phenomena, both in the innate immnune response and the adaptive immune response. To better understand the activation of effective immune response against pathogenic fungi, we researched the interaction between B-1 cells and Paracoccidioides brasiliensis (P. brasiliensis), since it expresses that antigenic molecules can be recognized by the immune system. We used antigenic preparation of P. brasiliensis obtained from the surface of yeast called CFA (cell free antigen) and yeast cells of the fungus. It was observed that most cells in the cell culture supernatant 4 days of total adherent peritoneal cells consisted of B-1 cells, these cells express high levels of MHC-II (100%) and CD80 (90%). However, no significant expression of co-stimulatory molecule CD86 was observed. After phenotypic analysis, the B-1 cells can act as anyigen-presenting cells because they express C80, CD86 and MHC-II, then realized proliferation assay using B-1 cells as antigen presenting cells inducing was performed, and our results showed the significant proliferation of CD4 T cells. Regarding cytokines, we analyzed the IL-10 secretion and TNF-α in culture supernatant of B-1 cells without stimulation and found that these cells secrete both IL-10 and TNF-α, after stimulation of CFA. We analyzed the expression of TLR-2, TLR-4, MyD88 and IL-10 by RT-PCR, of the B-1 cells in the presence of CFA. We found expression of TLR-2, MyD88 and IL-10 cells with and without stimulus. We analyzed the migration of peritoneal B-1 cells after intraperitoneal (ip) infection with yeast from P. brasiliensis. After 5 hours, high decrease of B-1 cells in the peritoneal cavity was observed, which remained for 24 hours and 7 days post-infection. To better understand the migration of B-1 cells, we used mice CBA/N Xid (destitute of B-1 cells), reconstituted with B-1 cells, and infected with yeast P. brasiliensis. The results show that after the infection, the B-1 cells migrate from the peritoneal cavity to the spleen. Also, there was an increase in the number of T cells with regulatory cell phenotype (CD4+CD25+Foxp3+). Our results suggest that high production of IL-10 by B-1 cells, probably mediated by the binding of TLR-2, along with the ability of B-1 cells in activating T lymphocytes, with the ability to migrate from the peritoneum to the spleen and activate T regulatory cells, could favor the survival of the fungus in the host.

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DeLuca, Carmela. "Molecular analysis of NF-[kappa]B activation in HIV-1 infected myeloid cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/NQ55319.pdf.

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Tremblay, Michel 1955. "Biological factors governing infection by HIV-1 of T cells and EBV- carrying B cells : (infection par le VIH-1 de lymphocytes T et de lymphocytes B transformes par EBV: caracteristiques biologiques)." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74257.

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The potential relationship between the Epstein-Barr Virus (EBV) and the Human Immunodeficiency Virus type 1 (HIV-1) in lines of EBV-carrying B cells that had been super-infected by HIV-1 was investigated. We found that such cells can produce high levels of viral particles, over long periods, with a minimal cytopathic effect and were less susceptible to HIV-1 infection than primary cultures of human peripheral blood mononuclear cells (PBMC).
We also investigated whether an alternative receptor, other than the well-known CD4 receptor, could permit HIV-1 infection of B cells immortalized by EBV. We detected a mechanism of complement-mediated antibody-dependent enhancement of HIV-1 infection in these cells implicating the CD4 receptor, the complement receptor type 2, and the alternate pathway of complement.
The fact that AZT is actually the most widely used drug in treating HIV-1 infections prompted us to investigate the ability of AZT to prevent infection and replication of HIV-1 in EBV-positive B cells. Three concentrations of AZT (1, 5 and 10 $ mu$M) prevented infection by one clinical isolate (334). In contrast, no such inhibitory effect was observed with each of a second clinical isolate (336) or with the HIV-III$ sb{ rm B}$ laboratory strain of HIV-1. Nevertheless, in these two particular cases, AZT significantly delayed and attenuated viral expression.
Finally, we determined that exposure of PBMC from HIV-1-infected individuals to preparations of HSV-1, HSV-2, or CMV stimulated the cells to become active producers of HIV-1 and point to a possible role for these viruses as co-factors in the pathogenesis of AIDS.

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Ferreira, Natália Soares. "Papel das células B-1 na infecção por Leishmania (L.) amazonensis." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/42/42135/tde-17082016-115850/.

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Parasitos do gênero Leishmania causam um espectro de doenças chamadas de leishmaniose. Para compreender de melhor forma a imunobiologia da Leishmania, o estudo de outras células envolvidas no processo de infecção do parasito se torna importante. As células B-1 são encontradas principalmente nas cavidades peritoneal e pleural, tendo como característica a capacidade de se diferenciar em células fagocíticas. Este trabalho teve como objetivo avaliar o papel das células B-1 na infecção por L. (L.) amazonensis. Os resultados mostraram que, assim como os macrófagos, os B-1CDPs são infectados pelo mecanismo de fagocitose e permitem a multiplicação da Leishmania no seu interior. Além disso, os vacúolos parasitóforos formados nos B-1CDPs apresentaram ser maiores do que dos macrófagos. Portanto, os dados com B1CDPs sugerem que estas células podem possuir um papel relevante na infecção por L. (L.) amazonensis, podendo ser considerados células hospedeiras importantes durante a infecção devido à incapacidade de responder de maneira eficaz para a eliminação dos parasitos.
The genus Leishmania parasites cause a spectrum of diseases called leishmaniasis. To better understand the immunobiology of Leishmania, the study of other cells involved in parasite infection process becomes important. The B-1 cells are found predominantly in the peritoneal and pleural cavities, whose feature consist on an ability to differentiate into phagocytic cells. This study aimed to evaluate the role of B-1 cells in the infection by L. (L.) amazonensis. The results showed that, like macrophages, B-1CDPs are infected by a mechanism of phagocytosis and allow the multiplication of Leishmania within. Furthermore, the parasitophorous vacuoles in the B-1CDPs showed to be larger than those formed in the macrophages. Therefore, B1CDPs can have an important role in infection by L. (L.) amazonensis and can be considered important host cells during infection due to inability to respond effectively to the elimination of parasites.

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Hansi, Navjyot Kaur. "Role of the inhibitory receptor LAIR-1 on NK cells in chronic hepatitis B." Thesis, Queen Mary, University of London, 2018. http://qmro.qmul.ac.uk/xmlui/handle/123456789/43992.

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There are multiple immune mechanisms identified for persistence of hepatitis B virus (HBV) infection. This thesis considers the vital role that inhibitory receptors play in contributing to impairment of the adaptive immune system in chronic hepatitis B (CHB), and the potential role they play in the innate immune system, focusing on the inhibitory receptor leucocyte-associated immunoglobulin-like receptor (LAIR)-1. The unique aspect of this work is that for the first time LAIR-1 expression has been investigated on natural killer (NK) cells in CHB. Our striking findings of increased LAIR-1 expression on peripheral NK cells in CHB and an inverse correlation between expression and effector function suggest this inhibitory receptor could have a potential role in exhaustion of NK cells in CHB. We therefore additionally explored the expression of LAIR-1 on circulating NK cells from patients with hepatocellular carcinoma (HCC) and non-alcoholic fatty liver disease (NAFLD). The particular relevance of LAIR-1 to liver disease is that one of its major ligands is collagen. We demonstrated a downregulation of LAIR-1 expression on intrahepatic NK cells, which we postulate might occur following repetitive engagement with abundant collagen within the liver. In line with this, intrahepatic NK cells with a liver-resident (CXCR6+) phenotype had even lower LAIR-1 expression than liver infiltrating (non-resident, CXCR6-) NK cells. Furthermore, preliminary experiments display attenuation of the cytotoxic degranulation capacity (CD107a) by circulating NK cells from CHB patients upon exposure to plate-bound collagen. We demonstrate differential expression of LAIR-1 on NK cells in viral hepatitis, HCC and NAFLD and between peripheral and intrahepatic NK cells. Preliminary experiments demonstrate a role in inhibiting NK cell function suggesting this as a novel therapeutic target to harness the capacity of NK cells to control chronic infection and cancer.

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Berg, Anna-Karin. "Enterovirus infections of b[beta]-cells a mechanism of induction of type 1 diabetes? /." Uppsala : Uppsala Universitet, 2005. http://www.diva-portal.org/smash/get/diva2:167155/FULLTEXT01.

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Thibult, Marie-Laure. "PD-1 et BTLA au coeur des lymphocytes B : du physiologique aux lymphomes." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX20701.

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La réponse immunitaires est régulée par des molécules de co-signalisation, qui, en apportant des signaux inhibiteurs ou activateurs, modulent les fonctions lymphocytaires. Nous avons focalisé notre étude sur deux co-effecteurs et membres de la famille CD28/B7 : PD-1 (Programmed Death 1) et BTLA (B and T Lymphocyte Attenuator), tous deux décrits, à l’image de CTLA-4, comme inhibitrices de l’activation lymphocytaire T. Au cours de ma thèse, nous avons pu évaluer l’expression et le rôle de PD-1 et BTLA sur les lymphocytes B normaux et pathologiques. Dans une première partie, nos travaux ont montré que ces molécules sont exprimées à la surface des sous populations B du sang périphérique et des tissus et qu’elles sont également finement régulées au cours de l’activation B. Par la suite nous avons démontré pour la première fois que BTLA et PD-1, à l’image des cellules T, sont recrutées, après activation, au niveau du récepteur de la cellule B et qu’elles exercent un rôle inhibiteur sur l’activation de ces mêmes cellules. Dans une seconde partie, grâce au développement d’un outil en cytométrie multicouleurs, nous avons analysé, dans une cohorte de 72 lymphomes B, l’infiltrat immunitaire ainsi que l’expression de PD-1, BTLA et leurs ligands. Ce travail, par son analyse de la physiologie B d’une part et de pathologies tumorales B d’autre part, donne un nouvel éclairage sur les rôles complexes des co-récepteurs BTLA et PD-1
The immune response is regulated by co-signaling molecules, which, by providing signals inhibitors or activators, modulate lymphocyte functions. We focused our study on two co-effectors and CD28/B7 family members: PD-1 (Programmed Death 1) and BTLA (B and T Lymphocyte Attenuator), both described, like CTLA-4, as inhibitors of T lymphocyte activation. This work allowed us to evaluate the expression and the role of BTLA and PD-1 on normal and tumoral B lymphocytes. In the first part, our work has shown that these molecules are expressed on B cell subsets of peripheral blood and tissues and are also finely regulated during the B cell activation. Subsequently, we have demonstrated for the first time that BTLA and PD-1, like T cells, are recruited after activation at the B cell receptor, and they exert an inhibitory role on the activation of these cells. In the second part, through the development of a multicolor cytometry tool, we analyzed the immune infiltrate and the expression of PD-1, BTLA and their ligands in a cohort of 72 B-cell lymphomas. Taken together, these results, by his analysis of the physiology of B cell from B cell malignancies, give a new insight into the complex roles of BTLA and PD-1 co-receptors

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Sampangi, Sandeep. "Autologous human kidney proximal tubule epithelial cells (PTEC) modulate dendritic cell (DC), T cell and B cell responses." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/82033/1/Sandeep_Sampangi_Thesis.pdf.

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This is a comprehensive study of human kidney proximal tubular epithelial cells (PTEC) which are known to respond to and mediate the pathological process of a range of kidney diseases. It identifies various molecules expressed by PTEC and how these molecules participate in down-regulating the inflammatory process, thereby highlighting the clinical potential of these molecules to treat various kidney diseases. In the disease state, PTEC gain the ability to regulate the immune cell responses present within the interstitium. This down-regulation is a complex interaction of contact dependent/independent mechanisms involving various immuno-regulatory molecules including PD-L1, sHLA-G and IDO. The overall outcome of this down-regulation is suppressed DC maturation, decreased number of antibody producing B cells and low T cell responses. These manifestations within a clinical setting are expected to dampen the ongoing inflammation, preventing the damage caused to the kidney tissue.

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Eusebio, Anthony R. "Characterization of downstream target genes regulated by ABF-1 in different states of B cell development." Scholarly Commons, 2005. https://scholarlycommons.pacific.edu/uop_etds/618.

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The ABF-1 gene encodes for a protein that belongs to the basic helix-loop-helix family of transcription factors. ABF-1 mRNA molecules have been detected in the lymphoid tissues, which include the bone marrow, lymph nodes, and appendix, as well as transformed B cells lines infected with Epstein-Barr virus. This study investigates the role of ABF-1 in regulating downstream target genes in the human mature B cell line RAJI, as well as the plasma cell line, ARH-77. Quantitative real-time polymerase chain reaction and DNA microarray technology was used to investigate target genes that are subjected to transcriptional regulation by ABF-1. Using ABF-1 inducible cell lines or B cell lines that overexpress ABF -1 by transient transfection experiments, we discovered many cellular genes that change in their transcriptional profiles in response to ABF -1 expression. Based upon the analysis of genes being affected following ABF-1 induction, our results support the hypothesis that ABF-1 primarily functions as a transcriptional repressor in vivo. Many genes that regulate the cellular processes of apoptosis, as well as the cell cycle, were repressed following ABF-1 expression. Because EBV has been reported to control ABF-1 gene expression, the identification of downstream target genes regulated by ABF-1 may provide insight into the molecular events that follow after EBV infection.

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Fujisawa, Akihiro. "Disease-associated mutations in CIAS1 induce cathepsin B-dependent rapid cell death of human THP-1 monocytic cells." Kyoto University, 2008. http://hdl.handle.net/2433/135800.

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Salomonsson, Maya. "Exploring innate type B cells in an animal model for autoimmune arthritis." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229792.

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B cells have a central role in the pathogenesis of collagen-induced arthritis (CIA), an animal model of the autoimmune disease rheumatoid arthritis. In this report, a specific subset of an innate type of B cells, B-1 B cells, have been studied for the involvement in CIA. The B-1 B cells were shown to produce small amounts of collagen-specific antibodies upon stimulation in vitro, suggesting that they play a minor role in the development of CIA. This report also includes how marginal zone B cells, another innate type of B cells with natural collagen-reactivity, can be identified in the medullary sinuses of lymph nodes of collagen-immunized mice, implying involvement in auto antigen trapping.

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Stevens, Joseph. "Coxsackievirus Infection of B Cells: Towards a Better Understanding of the Etiology of Type 1 Diabetes." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522418340151761.

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Prokopec, Kajsa. "B cells in Autoimmunity : Studies of Complement Receptor 1 & 2 and FcγRIIb in Autoimmune Arthritis." Doctoral thesis, Uppsala universitet, Molekylär immunologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-109428.

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B cells are normally regulated to prevent activation against self-proteins through tolerance mechanisms. However, occasionally there is a break in tolerance and B cells can become self-reactive, which might lead to the development of autoimmune disease. The activation of self-reactive B cells is regulated by receptors on the B cell surface, such as Fc gamma receptor IIb (FcγRIIb), complement receptor type 1 (CR1), and CR type 2 (CR2). In this thesis I have studied the role of FcγRIIb, CR1 and CR2 on B cells in autoimmune arthritis. By using a model for rheumatoid arthritis, I discovered that the initial self-reactive B cell response in arthritis was associated with the splenic marginal zone B cell population. Marginal zone B cells express high levels of CR1/CR2 and FcγRIIb, suggesting that they normally require high regulation. Further, female mice deficient in CR1/CR2 displayed increased susceptibility to arthritis compared to CR1/CR2-sufficient female mice. When investigating whether sex hormones affected arthritis susceptibility, we found that ovariectomy, of the otherwise fairly resistant CR1/CR2-sufficient mice, reduced the expression of CR1 on B cells and rendered the mice more susceptible to arthritis. In humans, a significantly reduced CR1 and FcγRIIb expression was found on B cells in aging women, but not in men. This may contribute to the increased risk for women to develop autoimmune disease as reduced receptor expression may lead to the activation of self-reactive B cells. In agreement, lower CR1, CR2 and FcγRIIb expression was seen in patients with rheumatoid arthritis. Finally, a soluble form of FcγRIIb was used to investigate FcγRIIb’s ability to bind self-reactive IgG in an attempt to treat autoimmune arthritis. Treatment of mice with established arthritis was associated with less self-reactive IgG antibodies and consequently less disease, suggesting that soluble FcγRIIb may be used as a novel treatment in arthritis.

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Jones, Gareth John. "The role and function of dendritic cells in HIV-1 infection with non-clade B isolates." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398254.

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Balzano-Foucher, Marielle. "Influence du microenvironnement stromal de la moelle osseuse sur le développement des lymphocytes B normaux et pathologiques." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4048.

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Chez l’adulte les premières étapes du développement hématopoïétique se déroulent dans la moelle osseuse (MO). La contribution de cellules d’origine mésenchymateuse, appelées niches stromales, a été démontrée dans le cas de la maintenance des cellules souches hématopoïétiques (CSH) et du développement des lymphocytes B (LB). Ainsi la maintenance des CSH dépend de niches périvasculaires sécrétant CXCL12 et SCF. Par ailleurs les LB les plus précoces (preproB) sont en contact de cellules stromales CXCL12+, puis migrent vers des cellules stromales exprimant l’interleukine-7 lors de leur différentiation en cellules proB. L’expression du préBCR, marque ensuite l’entrée dans le stade préB. À ce stade, les cellules sont au contact de cellules stromales galectine-1+.Malgré les progrès obtenus dans la compréhension du rôle des niches stromales, leur hétérogénéité et les mécanismes contrôlant la migration et l’adhésion des cellules hématopoïétiques en différenciation restent à mieux définir. Dans cet objectif, nous avons caractérisé phénotypiquement les cellules stromales de la MO mais aussi démontré l’existence d’une niche multi-spécifique, associée aux sinusoïdes et capable de soutenir les CSH et les LB.La contribution des niches dans le développement et la résistance aux traitements des Leucémies Aigues Lymphoblastiques de type B (LAL-B), équivalents pathologiques des LB en développement, a aussi été démontrée. Au cours de mon travail de thèse nous avons révélé l'influence d'un facteur exprimé par des cellules stromales de la MO sur la prolifération des LAL-B. À terme, ces travaux permettront de développer des traitements ciblant les fonctions protectrices des niches tumorales
In adults, the early stages of hematopoietic development take place in the bone marrow (BM). The contribution of specialized cells of mesenchymal origin, called stromal niches, has been demonstrated in the case of hematopoietic stem cell (HSC) maintenance and B lymphocyte development. Indeed, the maintenance of HSC depends on perivascular niches secreting CXCL12 and SCF. Furthermore progenitor B cells (preproB) are in contact with CXCL12+ stromal cells and migrate towards interleukin 7 expressing stromal cells during their differentiation into proB cells. PreBCR expression then marks the entrance into the preB cell stage. At this point, the cells are in contact with galectin-1+ stromal cells.Although progress have been made in understanding the role of stromal cell niches, their heterogeneity and the mechanisms controlling migration and adhesion of differentiating hematopoietic cells are controversial and remain to be defined. With this objective, we characterized phenotypically BM stromal cells but also demonstrated the existence of a multi-specific niche, associated to sinusoids and able to support both HSC and early B cells.The contribution of BM niches in the development and resistance to treatment of B cell Acute Lymphoblastic Leukemia (B-ALL), pathological equivalent of developing B cells has also been demonstrated. During my PhD, our work revealed the influence of a factor expressed by BM stromal cells on the proliferation of B-ALL. Ultimately, this work will allow the development of treatments targeting the protective functions of tumor niches

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CAMPOS, Patrícia Isabel Figueiredo. "Characterization of T follicular helper (Tfh) cells and B cell isotype switching induced by type 1 and type 2 adjuvants." Master's thesis, Instituto de Higiene e Medicina Tropical, 2016. http://hdl.handle.net/10362/20059.

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A principal função dos linfócitos T CD4+ é fornecer apoio a outras células no sentido de gerar uma resposta imunitária eficiente. As interações entre as células T e B são essenciais para a produção de respostas humorais, sendo que foi recentemente demonstrado que as células T foliculares auxiliares (Tfh) desempenham um papel crucial neste processo. Caracteristicamente, expressam o fator de transcrição Bcl-6, o recetor de quimiocinas CXCR5 e o marcador de superfície PD-1. A expressão destes marcadores é única e fundamental para que estas células possam aceder ao folículo de células B, onde orientam as reações no centro germinativo (GC), levando à consequente mudança de isótipo, maturação da afinidade, produção de anticorpos de alta afinidade e células B de memória. Neste projeto, foram testadas duas hipóteses opostas no sentido de caracterizar fenotipicamente as células Tfh. Propomos investigar se estas são especializadas no fornecimento de auxílio do tipo Th1 ou Th2, que designamos de células hipotéticas "Tfh1" e "Tfh2" (Hipótese 1) ou se são uma subpopulação genérica que responde igualmente na presença de diferentes antigénios, células Tfh (Hipótese 2). Deste modo, murganhos C57BL/6J e Balb/c foram imunizados na almofada plantar da pata traseira, utilizando proteína Ovalbumin (OVA) combinada com diferentes tipos de adjuvantes: CpG ODNs isoladamente e em combinação com TiterMax® Gold (TMX), Sigma Adjuvant System (SAS) e Montanide ISA 720 VG, testados como adjuvantes tipo 1, e por sua vez Incomplete Freund’s Adjuvant (IFA) e Alum experimentados como adjuvantes do tipo 2. A técnica de ELISA permitiu determinar no soro dos murganhos o tipo de resposta gerada, através da medição de imunoglobulinas específicas para OVA (IgG2a para Th1, IgG1 e IgE total para Th2). CpG ODNs e IFA foram considerados como os adjuvantes mais apropriados para induzir respostas Th1 e Th2, respetivamente. Células T que reconhecem especificamente OVA foram colhidas de murganhos OT-II Rag-/- e DO11.10 Rag-/- e transferidas para murganhos congénicos. De seguida, procedeu-se à imunização tal como descrito acima. Os nódulos linfáticos drenantes foram recolhidos no pico da reação do centro germinativo (11 dias após imunização), assim como as células Tfh específicas para OVA (CD4+CD44+ CXCR5+PD-1+ Thy1.2+Vβ5+Vα2+/DO11.10+) e as células T auxiliares ativadas específicas para OVA (CD4+CD44+CXCR5-PD-1- Thy1.2+Vβ5+Vα2+/DO11.10+). A caracterização molecular destas populações de células T está a ser analisada através da sequenciação dos seus transcritos pela técnica de RNA-sequencing. Além disso, a expressão de marcadores de Th1 e Th2 em células Tfh foi analisada através de citometria de fluxo e Reação em Cadeia da Polimerase quantitativa por Transcrição Reversa (RT-qPCR). Neste estudo, foi demonstrado que as células Tfh co-expressam Bcl-6 e T-bet e também produzem IFN-γ, quando sensibilizadas com OVA-CpG ODNs, características concordantes com os marcadores fenotípicos de uma célula Tfh e célula Th1. A expressão de Gata-3 (marcador Th2) só foi detetada sob estimulação IFA-OVA, embora em níveis mais baixos do que as determinadas para T-bet.
The major function of CD4+ T cells is to provide help to other lymphocytes to mount an efficient immune response. T and B cell interactions are essential for humoral responses and it was recently shown that T follicular helper (Tfh) cells play a crucial role in this process. They characteristically express the transcription factor Bcl-6, chemokine receptor CXCR5 and PD-1. These markers are unique as their expression is pivotal to acquire access to the B cell follicle and drive germinal centre (GC) reactions, leading to isotype switching, affinity maturation, and production of high affinity antibodies and memory B cells. In this project, two competing hypothesis investigating the phenotype of Tfh cells were tested. We propose to dissect whether Tfh cells are specialized in providing Th1 or Th2 help, which we call putative “Tfh1” and “Tfh2” cells (hypothesis 1), or if they are a more generic Th subset that responds equally in the presence of different antigens, which we designate as Tfh cells (hypothesis 2). Therefore, we immunized C57BL/6J and Balb/c mice in the footpad using Ovalbumin (OVA) protein combined with different adjuvant types: CpG ODNs only and combined with TiterMax® Gold (TMX), Sigma Adjuvant System (SAS) and Montanide ISA 720 VG, as type 1 adjuvant, and Incomplete Freund’s Adjuvant (IFA) and Alum as type 2 adjuvants. Using ELISA assays to determine the type of response generated by measuring serum immunoglobulins of distinct clones (OVA-specific IgG2a for Th1 and OVA-specific IgG1 and total IgE for Th2), we considered CpG ODNs and IFA as the most appropriate adjuvants to induce Th1 and Th2 responses, respectively. OVA-specific cells were transferred from OT-II Rag-/- and DO11.10 Rag-/- mice into congenic mice subsequent to immunization as described above. Draining LNs were collected at the peak of the GC reaction (day 11 post-immunization) and OVA-specific Tfh cells (CD4+ CD44+ CXCR5+PD-1+ Thy1.2+Vβ5+Vα2+/DO11.10+) and OVA-specific activated-Th cells (CD4+ CD44+ CXCR5-PD-1- Thy1.2+Vβ5+Vα2+/DO11.10+) were sorted. The molecular signature of these T cell populations is being analysed via RNA-Sequencing. Moreover, the expression of Th1 and Th2 markers on Tfh cells was investigated via flow cytometry and Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR). In this study, it could be shown that Tfh cells of mice immunized with OVA-CpG ODNs co-expressed Bcl-6 and T-bet and also produced IFN-γ, both concordant features with the phenotypic markers of a Tfh cell and of a Th1 cell. As for the expression of Gata-3, it has only been detected in mice under IFA-OVA stimulation, even though at levels lower than the ones determined for T-bet.

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Yang, Cheng-Tao. "Manipulating transcription factors in human induced pluripotent cell-derived cells to enhance the production and the maturation of red blood cells." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28928.

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The most widely transfused blood component is red blood cells (RBCs), and voluntary donation is the main resource for RBC transfusion. In the UK, 7,000 units of RBCs are transfused daily but this life-saving cell therapy is completely dependent on donors and there are persistent problems associated with transfusion transmitted infections and in blood group compatibility. Furthermore, the quality, safety and efficiency of donated RBCs gradually decrease with storage time. A number of novel sources of RBCs are being explored including the production of RBCs from adult haematopoietic progenitor cells, erythroid progenitor cell lines and induced pluripotent stem cells (iPSCs). The iPSC source could essentially provide a limitless supply and a route to producing cells that are matched to the recipient. A number of protocols have been described to produce mature RBCs from human pluripotent stem cells but they are relatively inefficient and would be difficult to scale up to the levels required for clinical translation. We tested and evaluated a defined feeder- and serum-free differentiation protocol for deriving erythroid cells from hiPSCs. RBC production was not efficient, the cells that were produced did not enucleate efficiently and they expressed embryonic rather than adult globin. We hypothesised that the production of RBCs from iPSCs could be enhanced by enforced expression of erythroid-specific transcription factors (TFs). Previous studies had demonstrated that Krüppel-like factor 1 (KLF1) plays an important role in RBC development and maturation so we generated iPSC lines expressing a tamoxifen-inducible KLF1-ERT2 fusion protein. Using zinc finger nuclease technology, we targeted the expression cassette to the AAVS1 locus to ensure consistent expression levels and to avoid integration site specific effects and/or silencing. These iKLF1 iPSCs were applied to our defined RBC differentiation protocol and the activity of KLF1 was induced by adding tamoxifen. Activation of KLF1 from day 10 accelerated erythroid differentiation and maturation with an increase in the proportion of erythroblasts, a higher level of expression of erythroid genes associated with maturation and an apparently more robust morphology. However, KLF1 activation had an anti-proliferation effect resulting in significantly less cell generated overall and HPLC analysis demonstrated that KLF1-activated cells expressed higher levels of embryonic globin compared to control iPSCs-derived cells. Many of the effects that were observed when KLF1 was activated from day 10 were not observed when activated from day 18. We therefore concluded that activation of exogenous KLF1 is able to promote erythroid cell production and maturation in progenitors (day 10) but not at the later stage of erythropoiesis (day 18). We hypothesised that KLF1 might require a co-factor to regulate RBC maturation and adult globin expression at the later stage of erythropoiesis. The TF, B-cell lymphoma/leukaemia 11a (BCL11A), plays a key role in the suppression of foetal globin expression, thereby completing globin switching to adult globin. Preliminary data showed that iPSC-derived erythroid cells were able to express adult globin when transduced with a BCL11A-expressing lentiviral-vector. Based on that finding we then generated an iPSC line expressing tamoxifen-inducible BCL11AERT2 and KLF1-ERT2 fusion proteins, applied this iBK iPSC line to our differentiation protocol. Activation of both TFs from day 18 slightly increased the expression of genes associated with RBC maturation and the inclusion of BCL11A appeared to eliminate the anti-proliferation effect of KLF1. Most importantly, activation of both BCL11A and KLF1 from day 18 of the differentiation protocol increased the production of α- globin (foetal / adult globin) indicating that some definitive-like erythroid cells might be generated by activation of both TFs at the later stage of erythroid differentiation. Collectively, these findings demonstrate that enforced expression of erythroid TFs could be a useful strategy to enhance RBC maturation from iPSCs.

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Fauteux, Lucy J. "Regulation of B lymphopoiesis within bone marrow microenvironment, in vivo role of IL-1 and expression of surrogate light chains by precursor B cells in the mouse." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ29932.pdf.

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Fauteux, Lucy J. (Lucy Jacinthe). "Regulation of B lymphopoiesis within bone marrow microenvironment : in vivo role of IL-1 and expression of surrogate light chains by precursor B cells in the mouse." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=42027.

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The control of B lymphocyte production in bone marrow is of central importance in maintaining a supply of new B cells for primary humoral immune responses throughout life, while its perturbation may underlie states of immunodeficiency, neoplasia and autoimmunity. Molecules expressed by developing B cells and stromal cells within bone marrow, as well as systemic factors, may all play key roles in regulating proliferation and survival of precursor B cells in bone marrow. Candidate regulatory molecules investigated in the present work include surrogate light chains (SL) of immunoglobulin (Ig) expressed intracellularly by precursor B cells before and during the synthesis of CI heavy (H) chains of IgM, and interleukin (IL)-1, a systemic pleiotropic macrophage-derived factor. In vivo administration of radiolabeled mAbs specific for SL and IL-1 receptors type I and type II revealed that both SL and IL-1 receptors are normally expressed in bone marrow, displayed on the surface of lymphoid precursors and stromal cells, respectively. Ex vivo analysis of the DNA content of SL/$ mu$H$ sp+$ pre-B cells revealed a low incidence of apoptosis. Systemic administration of rIL-1 followed by analysis of precursor B cell dynamics using double immunofluorescence labeling and stathmokinetic techniques revealed that systemic IL-1 can either stimulate or depress B lymphopoiesis in a dose-dependent manner. Stimulation of cytoplasmic (c) $ mu sp+$ pre-B cell proliferation following activation of systemic macrophages by injecting sheep red blood cells (SRBC) is partially abrogated by rIL-1ra. Bone marrow IL-1 receptors, assayed by binding of radiolabeled anti-IL-1R monoclonal antibodies to plasma membrane fractions, undergo changes in levels of expression following SRBC administration. The work supports the hypotheses that surface SL is involved in the positive selection of precursor B cells with productively-rearranged $ mu$ chain genes, and suggests that the elevated proliferative level o

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Thyagarajan, Radha. "Anomalies in humoral immunity in the NOD mouse : contribution to the progression of type 1 diabetes." Doctoral thesis, Umeå universitet, Immunologi/immunkemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-125001.

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The non-obese diabetic (NOD) mouse is widely used model Type 1 diabetes (T1D), a chronic inflammatory disease characterized by destruction of the insulin producing β cells in the islets of Langerhans by immune cells. The classical symptoms include increased glucose levels in urine and blood, frequent urination and enhanced thirst. The disease has a strong genetic component and is also influenced by the environment. NOD mice develop T1D spontaneously. The disease occurs in two phases; insulitis - the infiltration of immune cells in the islets of Langerhans and overt diabetes caused by the destruction of insulin producing β cells. Several disease associated gene regions or loci [termed insulin dependent diabetes (Idd) loci] have been associated with T1D development. Although, T1D is recognized as a T cell mediated disease in both mouse and man, many studies have shown the importance of B cells in the pathogenesis of the disease. Autoantibodies appear prior to islet infiltration and several molecular and cellular events precede this beta-cell autoimmunity. Although the pathogenesis of T1D is well characterized, less is known about the environmental and immunological factors that trigger the disease. In this thesis, we studied the contribution of B cell anomalies to the skewed immune response observed in the NOD mouse. In our studies covered in the thesis we observed that NOD mice display enhanced IgE in the serum already at one week of age. In addition, upon treatment of pre-diabetic NOD mice with anti-IgE antibodies, diabetes incidence was delayed. We hypothesize that the presence of IgE in the system may be explained due to enhanced class switching. Antibody feedback however, is an essential component of the immune response and can lead to either enhanced or dampened responses. Thus, increased IgE may provide positive feedback that might sustain an immune response. We also aimed to analyze the biological consequence of this feature. In vitro stimulation of B cells by the TACI ligand APRIL resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. In addition, TACI+ cells were observed in NOD germinal centers facilitating increased BAFF uptake and subsequent escape of low affinity antibody producing clones. NOD mice elicited an enhanced and prolonged immune response towards T-dependent antigens such as hen-egg lysozyme (HEL). Serum HEL-specific IgG level was significantly increased and was predominantly of the IgG1 isotype. Immunofluorescence analysis of NOD spleen revealed the presence of spontaneous germinal centers which others have perceived to provide a ready niche for the entry of naïve B cells that encountered novel antigen. Adoptive transfer experiments of purified B and T cells from NOD into NOD.Rag2-/- (NOD-RAG) mice illustrated the importance of B cell intrinsic defects in the reproduction of the original phenotype as observed in NOD.

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Fehlner-Gardiner, Christine C. "Expression and function of B-1 integrins during the development of murine bone marrow-derived mast cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0001/NQ40257.pdf.

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Banday, Viqar. "Metab-Immune analysis of the non-obese diabetic mouse." Doctoral thesis, Umeå universitet, Immunologi/immunkemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-119444.

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Type 1A diabetes mellitus or T1D is a chronic disease characterized by T cell mediated destruction of the insulin producing β cells in the islets of Langerhans. The classical symptoms include high glucose levels in urine and blood, polyuria, and polydipsia. Complications associated with T1D include blindness, amputations, and end-stage renal disease, and premature death. The non-obese diabetic (NOD) mouse, first described in 1980, is widely used as a model organism for T1D. T1D disease in the NOD mouse shares a number of similarities to human T1D including dependence on genetic and environmental factors. More than 30 disease associated gene regions or loci (termed insulin dependent diabetes, or Idd, loci) have been associated with T1D development in NOD. For some of these Idds, the corresponding region in human has been linked to the development of T1D in human. T1D, both in humans and mice, is recognized as a T cell mediated disease. However, many studies have shown the importance of both the metabolome and the immune system in the pathogenesis of the disease. Appearance of autoantibodies in the serum of patients is the first sign of pathogenesis. However, molecular and cellular events precede the immune attack on the β-cell immunity. It has been shown that patients who developed T1D have an altered metabolome prior to the appearance of autoantibodies. Although much is known about the pathogenesis of T1D, the contribution of the environment/immune factors triggering the disease is still to be revealed. In the present study both metabolic and immune deviations observed in the NOD mouse was analyzed. Serum metabolome analysis of the NOD mouse revealed striking resemblance to the human metabolic profile, with many metabolites in the TCA cycle significantly different from the non-diabetic control B6 mice. In addition, an increased level of glutamic acid was of the most distinguishing metabolite. A detailed bioinformatics analysis revealed various genes/enzymes to be present in the Idd regions. Compared to B6 mice, many of the genes correlated to the metabolic pathways, showed single nucleotide polymorphism (SNP), which can eventually affect the functionality of the protein. A genetic analysis of the increased glutamic acid revealed several Idd regions to be involved in this phenotype. The regions mapped in the genetic analysis harbor important enzymes and transporters related to glutamic acid. In-vitro islet culture with glutamic acid led to increased beta cell death indicating a toxic role of glutamic acid specifically towards insulin producing beta cells. In the analysis of the immune system, B cells from NOD mice, which are known to express high levels of TACI, were stimulated with APRIL, a TACI ligand. This resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. NOD mice have previously been shown to react vigorously to T-dependent antigens upon immunization. In this study we confirmed this as NOD mice showed an enhanced and prolonged immune response to hen egg lysozyme. Thus, serum IgG levels were significantly increased in the NOD mice and were predominantly of the IgG1 subtype. Immunofluorescence analysis revealed increased number of germinal centers in the NOD mice. Transfer of purified B and T cells from NOD to an immune deficient mouse could reproduce the original phenotype as seen in the NOD mice. Collectively, this thesis has analyzed the metabolomics and immune deviations observed in the NOD mice.

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Palm, Anna-Karin E. "Function and Regulation of B-cell Subsets in Experimental Autoimmune Arthritis." Doctoral thesis, Uppsala universitet, Kemisk biologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-265024.

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B lymphocytes play a significant role in autoimmune arthritis, with their function stretching beyond autoantibody production to cytokine secretion and presentation of autoantigen. However, the involvement and activation of different B-cell subset in the autoimmune response is not fully clear. The main focus of this thesis has been to understand the contribution of marginal zone (MZ) B cells in the induction of collagen-induced arthritis (CIA), a mouse model for rheumatoid arthritis (RA). We show that MZ B cells in the spleen of naïve mice display a natural self-reactivity to collagen type II (CII), the autoantigen used for immunization of CIA. The CII-reactive MZ B cells expand rapidly following immunization with CII, and produce IgM and IgG antibodies to CII. They also very efficiently present CII to cognate T cells in vitro and in vivo. Moreover, absence of regulatory receptors such as CR1/2 or FcγRIIb on the MZ B cells increases their proliferation and cytokine production in response to toll-like receptor, but not B-cell receptor, activation. Further, FcγRIIb-deficient MZ B cells present CII to T cells more efficiently than wild-type MZ B cells. We additionally demonstrate for the first time the existence of a small population of nodal MZ B cells in mouse lymph nodes. Similar to splenic MZ B cells, the nodal MZ B cells expand after CIA induction, secrete IgM anti-CII antibodies and can present CII to cognate T cells. Finally, we show that mast cells, associated with ectopic B cell follicles in inflamed RA joints, in coculture with B cells promote their expansion, production of IgM and IgG antibodies as well as upregulation of CD19 and L-selectin. Coculture with mast cells further causes the B cells to upregulate costimulators and class II MHC, important molecules for antigen-presenting function. In summary, my findings suggest that splenic and nodal self-reactive MZ B cells participate in breaking T-cell tolerance to CII in CIA. B-cell intrinsic regulation is needed to keep such autoreactive B cells quiescent. Mast cells can potentiate B-cell responses locally in the arthritic joint, thus feeding the autoimmune reaction.

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Creery, W. David. "Effects of immunoregulatory cytokines on B7-1 and B7-2 isoform expression on human monocytes and B cells." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/10195.

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T cell activation and the generation of effective immune responses is critically dependent on APC-derived signalling. The relative expression of B7 isoforms on APC may be important in determining the nature and extent of the immune response, and immunoregulatory cytokines may mediate their effects through alterations in B7 isoform expression. The effects of a panel of cytokines on B7 isoform expression on resting and activated monocytes and B cells was evaluated. IL10 and IL4, which induce the development of Th2 type T cells, downregulated expression of B7-2 and modestly upregulated expression of B7-1 on unstimulated human monocytes. IFN$\gamma,$ a potent inducer of Th1 type T cells, upregulated both B7-1 and B7-2 expression. TNF$\alpha$ downregulated B7-2 expression, but did not alter B7-1 expression. Addition of anti-IL10 antibodies did not abrogate the effects of TNF$\alpha$ on B7-2 expression. LPS had effects on B7 isoform expression on purified monocytes similar to those of IL10 in PBMC, namely marked B7-2 downregulation and modest B7-1 upregulation. None of the cytokines influenced the levels of expression of B7 isoforms on either resting or activated B cells. Thus cytokines that influence development of T helper type immune responses have differential effects on expression of individual B7 isoform on monocytes but not on B cells. These findings may have important implications in activation and control of immune responses in infections, autoimmunity and malignancies.

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Anhê, Fernando Forato. "Regulação do perfil transcricional pelas SMADs 1, 5 e 8 em células b da linhagem INS1E." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/42/42137/tde-11082010-131326/.

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BMPs ocupam papel central na diferenciação e crescimento celulares. A sinalização intracelular das BMPs depende de substratos conhecidos como BR-SMADs (SMAD1/5/8). Em ilhotas pancreáticas de ratas grávidas, onde ocorre aumento da massa endócrina e da síntese e secreção de insulina, houve aumento da expressão do receptor BMPR1A. Em camundongos knockout para BMPR1A houve diminuição da expressão de genes-chave na exocitose de grânulos de insulina. Tais eventos estão associados à redução da atividade das BR-SMADs. O objetivo deste trabalho foi avaliar, em células b INS1E, o perfil de expressão gênica em larga escala após silenciamento das BR-SMADs. As expressões relativas de Munc18a, Munc18b e Snap23 foram reduzidas quando do silenciamento das BR-SMADs (n=3, p<0,05 vs CTL). O silenciamento de SMAD1 (n=3, p<0,05 vs CTL) ou SMAD5 (n=3, p<0,05 vs CTL) acarretaram redução do mRNA de Sintaxina 4. Conclui-se que as BR-SMADs estão envolvidas na regulação da secreção de insulina modulando proteínas envolvidas na fusão de vesículas contendo grânulos de insulina à membrana plasmática de células INS1E.
BMPs play a determinant role in cell differentiation and growth. BMP intracellular signaling involves the substrates know as BR-SMADs (SMAD1/5/8). BMPR1A receptor expression was upregulated in pancreatic islets from pregnant rats, in wich endocrine mass and insulin secretion are increased. Mice with attenuated BMPR1A signaling in b cells showed decreased expression of key genes involved in insulin exocytosis. These events are associated with reduction of BR-SMADs activity. The aim of this work was to perform a screening to evaluate changes in expression profiles after knockdown of BR-SMADs in INS1E b cells. Relative expressions of Munc18a, Munc18b and Snap23 were diminished after knockdown of the BRSMADs (n=3, p<0,05 vs CTL). Only SMAD1 (n=3, p<0,05 vs CTL) and SMAD5 (n=3, p<0,05 vs CTL) silencing caused reduction of sintaxin 4 expression. These data point to the involvement of BR-SMADs in the regulation of insulin secretion by modulating the expression of proteins responsible by fusion of insulin-containing granules to the membrane of INS1E cells.

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Landgraf, Taise Natali. "Receptor de aerobactina férrica de Escherichia coli - IutA: um novo antígeno T-independente do tipo 1." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/17/17147/tde-30072012-174116/.

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Alguns fatores de virulência em bactérias de microbiota normal, tais como sideróforos moléculas captadoras de ferro e determinadas fímbrias, possibilitam que esses microorganismos causem infecção quando a colonização ocorre fora de seu habitat normal. Dentre as diferentes espécies bacterianas da microbiota normal com potencial para causar doenças, como as infecções do trato urinário (ITUs), destaca-se Escherichia coli. Certas cepas dessa espécie bacteriana apresentam um plasmídeo (pColV) que contém um gene que codifica IutA, o receptor para a aerobactina férrica, que é um sideróforo frequentemente associado às ITUs. Recentemente, nosso grupo estabeleceu que IutA apresenta a capacidade de induzir proliferação de linfócitos B. Neste trabalho, objetivamos identificar as moléculas e os mecanismos que modulam a proliferação de linfócitos B induzida por IutA recombinante (rIutA) de E. coli. Para avaliar se a proliferação era dependente de outras células, foram realizados ensaios de proliferação de células B marcadas com CFSE utilizando o sobrenadante de macrófagos ou células dendríticas estimulados com rIutA, por 24 horas, ou coculturas em placas de transwell. As análises desses ensaios revelaram que a proliferação das células B induzida por rIutA é dependente de moléculas liberadas por células acessórias, ou seja, ocorre de forma indireta. Os resultados dos ensaios utilizando células deficientes da molécula adaptadora MyD88 mostraram dependência da sinalização por essa molécula nos linfócitos B, mas não nas células acessórias, para que ocorresse a proliferação. Posteriormente, os ensaios in vitro utilizando células de animais deficientes para TLR4, TLR2 e IL-33R mostraram que a sinalização por esses receptores é dispensável. Contrariamente, a utilização do antagonista do receptor de IL-1 reduziu significativamente a proliferação de células B tratadas com esse antagonista. Além disso, identificamos que rIutA leva à expressão de IL-1 em macrófagos e células dendríticas estimuladas com essa proteína. Assim, nossos resultados sugerem que rIutA de E. coli induz a proliferação policlonal de linfócitos B de maneira independente de células T, por um mecanismo mediado por células acessórias, como macrófagos e células dendríticas. Embora não identifiquemos o receptor macrofágico ou das células dendríticas a qual rIutA se liga, sugerimos que a ação de rIutA sobre essas células induz a produção de IL-1 que age sobre seu receptor em células B, induzindo-as a proliferação. Esses resultados abrem perspectivas de estudo de IutA como molécula estimuladora do tecido linfóide associado a mucosa, assim como evasina de E. coli patogênicas.
Indigenous bacteria may contain some virulence factors, such as siderophores iron chelator molecules and fimbriae, that allow these microorganisms to become pathogens in sites others than their normal habitat. Among the different indigenous bacterial species in the gut, Escherichia coli is one with potential to cause infections, mainly urinary tract infection (UTI). Certain strains of E. coli have a plasmid (pColV), which encode ferric aerobactin outer membrane receptor, IutA, often associated with UTI. Our group has recently described IutA as an inducer of B cell proliferation. Here, we identify the molecules and mechanisms that modulate the proliferation of B lymphocytes induced by recombinant IutA (rIutA) from E. coli. To determine whether the B cell proliferation induced by rIutA is dependent on other cell, we carried out assays with CFSE-labeled B cells cocultured separately with macrophages or dendritic cells stimulated with rIutA using transwell membranes or incubated with conditioned medium from these cells. The analysis of the results showed that rIutA indirectly induced the proliferation of B cells in a manner dependent on molecules released by accessory cells. When we analyzed the ability of rIutA in inducing proliferation of cells from mice deficient in adapter molecule MyD88, we found that this signaling molecule is crucial for signaling induced by rIutA in B cells, but not in accessory cells. A similar analysis with cells from mice deficient in Toll like receptor (TLR) 4, TLR2 or inteukin (IL-) 33 receptor revealed that these receptors were not required for rIutA signaling of any tested cells. Conversely, the pretreatment of the B cells with IL-1 receptor antagonist significantly decreased the proliferation of these cells in response to conditioned medium from cultures of IutAstimulated macrophages. Moreover, we determined that rIutA induced the expression of IL-1 in macrophages and dendritic cells stimulated with IutA. Altogether, our results suggest that IutA from E. coli induces polyclonal B-cell proliferation independently of T cells in a mechanism mediated by accessory cells such as macrophages and dendritic cells. Although the IutA-binding receptors from macrophages and dendritic cells have not been identified, we suggested that rIutA induces these cells to produce IL-1, which in turns acts on its receptor on B cells, triggering proliferation. These results open perspectives for studying IutA as a molecule that stimulates the mucosa-associated lymphoid tissue and as an immune-evasion molecule from pathogenic E. coli.

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Maho, Maud. "Evaluation des effets des traitements par Rituximab versus corticothérapie seule sur la réponse auto-réactive des patients atteints de pemphigus. First-line Rituximab combined with short-term Prednisone versus Prednisone alone for the treatment of Pemphigus (RITUX 3) : a prospective, multicentre, parallel-group, open-label randomised trial Risk factors for short-term relapse in patients with pemphigus treated by Rituximab as first-line therapy Rituximab and corticosteroid effect on Desmoglein specific B cells and T follicular helper cells in patients with Pemphigus Modifications or the transcriptomic profile of autoreactive B cells from pemphigus patients after treatment with Rituximab or standard corticosteroid regimen Long-term increase of Kcnn4 potassium channel surface expression on B cells in pemphigus patients after Rituximab treatment Rituximab is an effective treatment in patients with Pemphigus Vulgaris and demonstrates a steroid-sparing effect Modifications of the BAFF/BAFF-Receptor axis in patients with pemphigus treated with rituximab versus standard corticosteroids regimen. CD11C+ B cells are mainly memory cells prone to differentiate into antibody-secreting cells." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR132.

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Le pemphigus est une maladie auto-immune spécifique de la peau et des muqueuses provoqué par des auto-anticorps (Ac) spécifiques des desmogléines (Dsg) 1 ou 3. Ces Ac pathogéniques inhibent l'adhésion cellulaire des kératinocytes. Le pemphigus se déclenche par la conjonction d’événements rares impliquant l’émergence puis la coopération de lymphocytes B (LB) et de lymphocytes LT auto-réactifs dans un contexte génétique et environnemental particulier. Jusqu’à présent, la première ligne de traitement du pemphigus était constituée de fortes doses de corticoïdes, qui sont de puissants immunosupresseurs systèmiques. Le Rituximab (RTX), un Ac monoclonal chimérique anti-CD20, constitue une thérapeutique innovante aboutissant à l’élimination des LB. L’étude clinique RITUX 3 a été conçue pour évaluer l’efficacité et l’innocuité du traitement utilisant le RTX associé à une courte corticothérapie dans le traitement de première intention du pemphigus par rapport au traitement de référence par la corticothérapie standard (CS). Dans un premier temps, notre analyse clinico-biologique des patients après 24 mois a démontré que l’utilisation du RTX associé à de la prednisone à court terme en traitement de première intention chez les patients atteints de pemphigus foliacé et vulgaire modéré à sévère est à la fois plus efficace et mieux toléré que le traitement de référence par la prednisone seule (89% de patients versus 34%). Cette efficacité a été confortée à plus long terme après la reconstitution du répertoire lymphocytaire B avec un risque de rechute de 2% à 36 mois. La présence d’une forme sévère de pemphigus au diagnostic (PDAI ≥ 45) et d’un taux d’Ac anti-Dsg à 3 mois supérieur aux valeurs seuils (anti-Dsg1 ≥ 20 ou anti-Dsg3 ≥ 120) sont associés à un risque de rechute précoce de 50%. Ces deux facteurs prédictifs permettent d'identifier un sous-groupe de patients présentant un risque élevé de rechute nécessitant une perfusion d'entretien de RTX au 6ème mois. Dans un deuxième temps, nous avons étudié l’impact des traitements par RTX et par CS chez les patients atteints de pemphigus afin de mieux appréhender la réponse auto-immune. La caractérisation phénotypique des LB auto-réactifs et l’analyse de la fréquence des LB capables de sécréter des immunoglobulines (Ig)G anti-Dsg par une approche ELISPOT a permis d’établir que l’efficacité du traitement par RTX dans le pemphigus semble liée à l’élimination des LB mémoires CD27+IgG+ spécifiques des Dsg. Des LB auto-réactifs Dsg restent détectables après RTX suite à la reconstitution lymphocytaire B, mais ces LB ont un phénotype naïf et non commuté (IgM) et ne secrètent plus d’IgG. En revanche, la persistance des LB auto-réactifs capables de sécréter des IgG anti-Dsg après traitement par CS est certainement à l’origine des rechutes fréquentes. L’analyse de l’expression génique ciblée à l’échelle unicellulaire a démontré qu’initialement, les LB spécifiques des Dsg ont un profil pro-inflammatoire avec l’expression de trois gènes codant pour les interleukines (IL)-1β, IL-12p35 et IL-23p19 et pour le gène de l’IRF5 (Interferon regulatory factor 5) par rapport aux LB non auto-réactifs. Le RTX et la CS ont des effets différents sur l'expression de ces gènes mais les deux réduisent l’expression génique d’IL-1β qui semble jouer un rôle important dans la physiopathologie du pemphigus. Parallèlement, l’analyse transcriptomique puis protéique des LB isolés des patients en rémission complète ou incomplète 6 ans après l’étude RITUX 1 a mis en évidence une augmentation d'expression de KCNN4 (Potassium calcium-activated channel subfamily N member 4) à la surface des LB chez les patients atteints de pemphigus en rémission complète pouvant influencer la maturation des LB
Pemphigus is an autoimmune disease of the skin and mucous membranes caused by autoantibodies (Ab) specific to desmoglein (Dsg) 1 or 3. These pathogenic Ab inhibit cell adhesion of keratinocytes. The development of pemphigus is associated with the conjunction of many uncommon events involving the emergence and then the cooperation of auto-reactive B cells and T cells link to genetic and environmental factors. Until now, the first line of treatment consisted of high doses of corticosteroids. Rituximab (RTX), an anti-CD20 chimeric monoclonal antibody, is an innovative therapy that results in B cells depletion. The RITUX 3 clinical trial was designed to evaluate the efficacy and safety of RTX combined with a short-course glucocorticoid therapy as a first-line treatment of pemphigus versus the standard treatment with standard corticosteroids (CS). As a first step, our clinico-biological analysis of patients after 24 months has shown that the use of RTX combined with short-term prednisone as a first-line treatment in patients with moderate to severe pemphigus is both more effective and better tolerated than the reference treatment with prednisone alone. Respectively, 89% of patients versus 34% in each group and both pemphigus foliaceus and pemphigus vulgaris patients responded. This efficacy was confirmed in the longer term after reconstitution of the B lymphocyte repertoire with a risk of relapse of only 2% at 36 months. The presence of a severe form of pemphigus at diagnosis (PDAI ≥ 45) and an anti-Dsg Ab level at 3 months above threshold values (anti-DSG1 ≥ 20 or anti-DSG3 ≥ 120) are associated with 50% risk of early relapse. These two predictive factors make it possible to identify a subgroup of patients at high risk of relapse requiring a maintenance infusion of RTX at the 6th month. In a second step, we studied the impact of RTX and CS treatments in patients with pemphigus in order to better understand the autoimmune response. The phenotypic characterization of auto-reactive B cells and the analysis of the frequency of B cells able of secreting anti-Dsg immunoglobulin (Ig) G by an ELISPOT approach demonstrated that the efficacy of RTX treatment in pemphigus seems related to the elimination of IgG-switched Dsg memory B-cells. Dsg specific B cells remain detectable after RTX when B cells return, but these B cells have a naïve and non-switched (IgM) phenotype and no longer secrete IgG. On the other hand, the persistence of self-reactive Dsg B cells capable of secreting IgG anti-Dsg after treatment with CS is certainly at the origin of the frequency of relapses. The unicellular targeted gene expression analysis demonstrated that initially, Dsg-specific B cells have a pro-inflammatory profile with the overexpression of three genes encoding Interleukin (IL) -1β, IL-12p35 and IL-23p19 and for the IRF5 gene (Interferon regulatory factor 5) compared to non-self-reactive B cells. RTX and CS have different effects on the expression of these genes, but both reduce the gene expression of IL-1β, which seems to play an important role in the pathophysiology of pemphigus

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Akbay, Burkitkan. "Regulation of the Akt/mTORC1 Pathway by HIV Transcriptional Activator Tat in B Cells Modulation of mTORC1 Signaling Pathway by HIV-1 Production of Stable Cell Lines on the Basis of the Cultured RPMI 8866 B-Cells with Constant and Inducible Expression of the Human Immunodeficiency Virus Tat Protein HIV-1 Tat Activates Akt/mTORC1 Pathway and AICDA Expression by Downregulating Its Transcriptional Inhibitors in B Cells." Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASL026.

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Les lymphomes agressifs à cellules B sont la principale cause de décès chez les personnes infectées par le VIH-1, bien que les cellules B ne soient pas ciblées par le virus. Les mécanismes exacts du développement de ces lymphomes ne sont pas connus. Des études antérieures de notre équipe ont révélé que le HIV-1 Tat peut pénétrer les cellules B, où il peut induire la production de ROS, endommager l'ADN et augmenter les chances de translocations oncogènes spécifiques au lymphome de Burkitt. En outre, dans de nombreuses cellules immunitaires, le VIH-1 et ses protéines (par exemple Tat) peuvent réguler la voie Akt/mTORC1, un intégrateur central de nombreux signaux intra et extracellulaires, y compris l'infection virale et les dommages à l'ADN. Cependant, aucune étude n'a examiné la régulation de la voie Akt/mTORC1 par Tat dans les cellules B. J'ai testé dans cette thèse l'hypothèse selon laquelle Tat pourrait produire des effets oncogènes dans les cellules B en modulant la voie de signalisation Akt/mTORC1 et en régulant l'expression des gènes impliqués dans la lymphomagenèse. J'ai découvert que HIV-1 Tat activait la voie de signalisation Akt/mTORC1, ce qui entraîne une activation aberrante de l'AICDA (cytidine désaminase induite par l'activation) en raison de l'inhibition des répresseurs transcriptionnels c-Myb et E2F8 de l'AICDA. Ces perturbations peuvent finalement conduire à une instabilité génomique accrue et à une prolifération qui pourrait provoquer des malignités des cellules B
Aggressive B cell lymphomas are the main cause of death in HIV-1 infected individuals, although B cells are not targeted by the virus. The exact mechanisms of the development of these lymphomas are not known. Previous studies of our team revealed that HIV-1 Tat can penetrate B cells, where it can induce ROS production, DNA damage and increase the chances of the oncogenic translocations specific for Burkitt lymphoma. In addition in many immune cells HIV-1 and its proteins (e.g. Tat) can regulate Akt/mTORC1 pathway, a central integrator of many intra and extracellular signals including viral infection and DNA damage. However, no studies have examined the regulation of Akt/mTORC1 pathway by Tat in B cells. In this thesis I have tested the hypothesis that HIV-1 Tat might produce oncogenic effects in B cells by modulating Akt/mTORC1 signaling pathway and regulating expression of genes involved in lymphomagenesis. I found that HIV-1 Tat activated Akt/mTORC1 signaling pathway, which leads to aberrant activation of AICDA (activation induced cytidine deaminase) due to inhibition of AICDA transcriptional repressors c-Myb and E2F8. These perturbations may ultimately lead to an increased genomic instability and proliferation that might cause B cell malignancies

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Decaudin, Camille. "Impacts fonctionnels et conséquences sur la différenciation hématopoïétique d’une mutation somatique récurrente du gène PU.1/SPI1 identifiée dans la macroglobulinémie de Waldenström A Recurrent Activating Missense Mutation in Waldenström Macroglobulinemia Affects the DNA Binding of the ETS Transcription Factor SPI1 and Enhances Proliferation." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL004.

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Le facteur de transcription PU.1/SPI1 de la famille ETS est un régulateur majeur de l'hématopoïèse, et de la différenciation des cellules souches, myéloïdes et lymphoïdes. Précédemment identifié comme un suppresseur de tumeur dans les malignités myéloïdes humaines, nous avons identifié une mutation somatique récurrente faux sens (Q226E) du gène PU.1 dans la macroglobulinémie de Waldenström, un syndrome lymphoprolifératif à cellules B. La mutation affecte la liaison à l'ADN de la protéine et permet au mutant de se lier et d'activer plus fréquemment les régions promotrices par rapport à la protéine de type sauvage. La liaison du mutant aux promoteurs active la transcription de gènes généralement activés par d'autres facteurs ETS, comme Ets1, entraînant une prolifération accrue dans les modèles de lignées cellulaires et les lymphocytes B primaires de souris. Pour analyser les propriétés du mutant dans des conditions physiologiques, nous avons développé un modèle de souris portant un allèle conditionnel Pu.1 Q226E Knock-In. L'utilisation d'un transgène CD19-Cre induit l'expression de la protéine mutée dans la lignée lymphoïde B. L'analyse du développement précoce des cellules B montre une augmentation de la réponse des cellules pré-B à l'IL-7, entraînant l'amplification de cette population in vivo. La protéine mutante stimule la prolifération cellulaire des lymphocytes B et augmente la différentiation des lymphocytes B en plasmocytes (CD138+). Plus précisément, ce mutant de Pu.1 semble augmenter précocement l'expression des facteurs de transcription spécifiques des plasmocytes, comme Blimp1 et Xbp1, et augmente l'activation de la voie UPR, permettant une différenciation plus importante des cellules B matures en plasmocytes. Ces résultats décrivent un mécanisme de subversion oncogénique de la fonction d’un facteur de transcription suite à la modification subtile de la spécificité de liaison à l'ADN de la protéine, qui affecte la prolifération et la différenciation
The ETS transcription factor PU.1/SPI1 is a major regulator of hematopoiesis. It is implicated in HSC, myeloid but also lymphoid biology and has been described as a tumor suppressor in human myeloid malignancies. We identified a PU.1 activating missense mutation in Waldenström macroglobulinemia (Q226E), a B-cell lympho-proliferative neoplasm, highlighting new oncogenic features for this transcription factor. This mutation affects the DNA-binding affinity of the protein and allows the mutant to more frequently bind to promoter regions with respect to wild-type protein, resulting in transcriptional activation of gene sets typically regulated by other ETS factors, such as ETS1, resulting in enhanced proliferation in model cell lines and murine primary B-cells. To analyze the properties of the mutant protein in physiological conditions, I developed mouse model carrying a Pu.1 Q226E Knock-In conditional allele. The use of a CD19-Cre transgene triggers the expression of the mutated protein in the B lymphoid lineage. Analysis of the early B cells development shows an increase response of pre-B cells to IL-7, associated to the accumulation of this population in vivo. I confirmed that the mutant protein stimulates B cell proliferation and showed that it also increases the differentiation of B cells into plasma cells (CD138+). Specifically, Pu.1 mutant induce an early increase of the expression of plasma-specific transcription factors, such as Blimp1 or Xbp1, and increases activation of the UPR pathway, which likely increases differentiation of mature B cells into plasma cells. These results describe a mechanism of oncogenic subversion of the function of a transcription factor as a result of the subtle modification of the DNA binding specificity of the protein, which affects proliferation and differentiation

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Li, Yuanhao. "Structural and functional study of bovine herpesvirus 1 glycoprotein B in the interaction with Madin Darby bovine kidney cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24030.pdf.

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Vasireddi, Mugdha. "Subversion of Natural Killer Cell Defenses Induced by a Deadly Zoonotic Virus." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/biology_diss/65.

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B virus (Macacine herpesvirus 1, Cercopithecine herpesvirus 1, herpes B virus) is an Old World monkey simplex virus endemic in macaques. B virus infection in its natural host, macaque, is very similar to HSV-‐1 infection in humans causing mild or asymptomatic infection. On the other hand, zoonotic infection in humans results in death in the absence of early initiation of antiviral drugs. Viruses evade host immune responses in order to survive and propagate. Most herpes viruses including HSV-‐1 down-‐regulate major histocompatibility complex class I (MHC class I) surface expression on infected cells in order to prevent CD8+ T-‐cell recognition and subsequent cell lysis. MHC class I molecules bind to the inhibitory receptors of NK cells and prevent NK cell activity. Thus, this mechanism protects HSV-‐1 infected cells from CD8+ T-‐cell lysis, making them sensitive to natural killer (NK) cell cytotoxicity. To investigate if B virus pathogenicity is a result of novel immune evasion mechanisms employed by B virus, we determined NK cell regulation during B virus infection. To this end, our experiments demonstrate that B virus does not down-‐ regulate MHC I expression as effectively as HSV-‐1, leading us to hypothesize that B virus in-‐ fected cells are resistant to NK cell activity. We examined the expression of MHC I chain related genes (MICA/ MICB), which are activation ligands to NKG2D receptors on NK cells. Our results show that there is no significant difference in MICA and MICB expression between HSV-‐1 and B virus infected cells. Furthermore, we tested for the up-‐regulation of cytokines and chemokines responsible for NK cell activation and migration. Our results indicate a significant up-‐regulation of IFN-‐α from PBMCs co-‐cultured with HSV-‐1 infected cells, which plays an important role in activating NK cells. NK cells within these PBMCs up-‐regulate perforin release indicative of NK cell activity. PBMCs co-‐cultured with B virus infected cells do not up-‐regulate any cytokines or chemokines responsible for NK cell activity. As a result the NK cells within these PBMCs do not significantly up-‐regulate perforin release. These results demonstrate that B virus employs a novel immune evasion mechanism to subvert NK cell activity.

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Motta, Vinícius. "The genetic basis of T and B cell contribution to autoimmune diabetes in NOD mice." Doctoral thesis, Umeå universitet, Medicinsk och klinisk genetik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-728.

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The nonobese diabetic mouse (NOD) is an excellent animal model to study type 1 diabetes. As with some humans, disease in the NOD mouse is effected by a combination of genetic and environmental factors. At least 20 insulin dependent diabetes (Idd) susceptibility loci have been identified so far, both in humans and in the NOD mouse. In this thesis, the overall aim has been to understand the genetic basis of diabetes in the NOD mouse by assessing immunogically-related phenotypes. As lymphocytes are the main players in the onset and progression to overt diabetes, we searched for physiological abnormalities in T and B cells, which could contribute to the breakdown of tolerance to pancreatic antigens. Ultimately, we postulate that abnormalities in the T or B cell compartments, under the genetic control of a previously defined diabetes susceptibility regions (Idds) could unravel the biological mechanisms underlying diabetes susceptibility and facilitate the identification of etiological polymorphisms involved in the disease. NOD T cells are defective in upregulating CTLA-4 upon in vitro activation. Previous studies have shown that this defect is, at least in part, controlled by gene(s) in the Idd5 region on chromosome 1. In paper I, we provide evidence that defective upregulation of the CTLA-4 in NOD T cells is not controlled by the Idd5.1 and Idd5.2 regions, but rather by genes linked to the telomeric region of chromosome 1 and to the Idd3 locus, for which the prime candidate gene is Il-2. Interestingly, we could restore some of the defective CTLA-4 expression in NOD T cells by the addition of exogenous IL-2 during T cell activation in vitro. In paper II, we show that NOD thymocytes are resistant to superantigen-mediated negative selection and that this trait is under control of the Idd5.2 region. Interestingly, it appears to operate in a T cell non-autonomous manner. In paper III, we describe a competitive advantage of NOD thymocytes to mature when they co-develop with B6 thymocytes in embryo aggregation chimeras. These results imply that defects exist in the positive/negative selection mechanisms in the NOD thymus. Apart from T cells, B cells also play an important role in the initiation of diabetes in NOD mice, probably as antigen presenting cells. In paper IV, we report that the genetic basis of an enlarged marginal zone (MZ) B cell population observed in the NOD mice is linked to the Idd9/Idd11 region. Together, these findings contribute to the dissection of the molecular mechanisms underlying diabetes pathogenesis, and shed light on the contribution of central and peripheral tolerance mechanisms to this process.

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Mc, Mullen C. B. Tara. "Comparison of herpes simplex virus type 1 and cytokine induction of ICAM 1 and NF#kappa#B expression on endothelial cells from different origins." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252310.

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Heine, Arndt Guido. "Der Einfluss von 1 alpha,25-Dihydroxy-Vitamin-D 3 auf die Aktivierung humaner B-Lymphozyten." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2001. http://dx.doi.org/10.18452/14695.

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Die Erkrankungen des atopischen Formenkreises sind durch eine hypererge Immunreaktion auf harmlose Umwelt-Antigene gekennzeichnet und umfassen u.a. die klinischen Bilder der allergischen Rhinokonjunktivitis, des allergischen Asthmas und der atopischen Dermatitis. Die Pathogenese atopischer Krankheiten ist zwar noch nicht hinreichend aufgeklärt, aber man schreibt der Regulation des IgE bei der Entstehung und Erhaltung dieser Krankheiten eine zentrale Rolle zu. Auf der Suche nach potentiellen anti-allergischen Therapeutika wurde in dieser Arbeit erstmalig der Einfluß von 1alpha,25-Dihydroxyvitamin-D3 (VD) und dem niedrigkalzämischen Derivat EB1089 in vitro auf die IgE-Produktion humaner B-Zellen gesunder Spender untersucht, die zuvor mit anti-CD40+IL-4 stimuliert wurden, wodurch der Isotypenklassenwechsel nativer B-Zellen nach IgE resultierte. Das Steroidhormon VD ist für die Kalziumhämostase essentiell, jedoch sind die immunregulatorischen Funktionen des VD noch relativ unerforscht. Die Experimente dieser Arbeit zeigen eine starke, dosisabhängige Hemmung der IgE-Produktion in diesem Modell, die spezifisch von VD und dem Derivat EB1089 vermittelt wird. Auch bei PBMC atopischer Spender konnte die basale IgE-Produktion mit VD dosisabhängig signifikant gehemmt werden. Eine mögliche Proliferationshemmung, die diese Wirkung erklären könnte, konnte ausgeschlossen werden. Die Messung der Produktion der anderen Immunglobulinklassen (Ig) IgA, IgG und IgM bestätigte, daß die Zellviabilität und die Ig-Produktion außer der von IgE durch VD und EB1089 in diesem Modell nur wenig beeinflußt wird. Diese Beobachtungen weisen auf eine selektive, spezifische Inhibition der IgE-Synthese durch das Molekül aus der Familie der Steroidhormone hin. Auf der Suche nach möglichen indirekten Mechanismen der IgE-Regulation, die die VD-vermittelte Inhibition der IgE-Synthese erklären könnten, wurde der Einfluß von VD auf die Expression der kostimulatorischen Faktoren der IgE-Produktion CD23 (Fc(-RII), CD54 (ICAM-1) und CD86 (B7.2) sowie auf die Sekretion der Zytokine, IL-6, sCD23 und IFN-gamma untersucht. Die Ergebnisse dieser Arbeit deuteten jedoch nicht auf eine Beteiligung der genannten Faktoren an der Regulation der VD-vermittelten Hemmung der IgE-Produktion hin. Diese in vitro Arbeit stellt einen wichtigen Hinweis auf eine potentielle Nutzung von VD in der anti-allergischen Therapie dar, jedoch deutet die beobachtete Hemmung der IgE-Synthese von PBMC atopischer Spender darauf hin, daß auch in vivo die IgE-Synthese gehemmt werden kann. Es sind daher weitere Studien des Signalweges des VD auf molekularer Ebene, sowie in vivo Versuche notwendig, um zu klären, ob VD selbst oder ein möglichst nicht-kalzitropes VD-Derivat mit ausgeprägten immunologischen Eigenschaften für die anti-allergische Therapie geeignet ist.
Atopic diseases are characterized by a hyperergic immunoreaction towards harmless environmental antigens, expressed by the clinical phenotype of allergic rhinitis, allergic asthma and atopic dermatitis. Even though the pathogenesis of atopic diseases are not completely clear, the regulation of IgE plays a crucial role in the development and maintenance of these disorders. In search of new potentially anti-allergic drugs, the effect of 1alpha,25-Dihydroxyvitamin-D3 (VD) and the low-calcemic synthetic analogue EB1089 was determined in anti-CD40+Il-4-mediated IgE-production by B-cells of healthy donors in vitro. The essential role of VD in calcium hemostasis is well understood, but the immunoregulatory functions of the hormone are still quite unclear. The present data show for the first time, that VD and the analogue EB1089 mediate a strong, dose-dependent inhibition of IgE-synthesis. In PBMC of atopic donors, the baseline IgE-production was also significantly inhibited by VD. Anti-CD40+IL-4-mediated proliferation of B-cells in the presence of VD was only modestly modulated, as well as the production of the other immunoglobulin-isotypes IgA, IgG and IgM. Taken together these data suggest a specific and selective inhibition of IgE-synthesis by VD and EB1089. In order to explore possible mechanisms of VD induced IgE-inibition, the expression of CD23 (Fc(-RII), CD54 (ICAM-1) and CD86 (B7.2) on anti-CD+IL-4 stimulated B-cells was determined as well as IL-6, sCD23 und IFN-gamma. However, none of these molecules were significantly modulated in the presence of VD. Taken together, these in vitro experiments suggest a potential role of VD as a new anti-allergic drug, which is underlined by the observed inhibition of IgE-production by PBMC in allergic donors.

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Ifie, Eseoghene. "An investigation of Coxsackie and Adenovirus receptor in the human pancreatic beta cells." Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/34559.

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Human pancreatic beta cells are susceptible to infection by enteroviruses, especially Coxsackie B viruses, and such infections could contribute to the development of Type 1 diabetes. Enteroviruses gain entry via cell surface receptors, one of which, the Coxsackie and Adenovirus receptor (CAR), is a transmembrane cell adhesion protein which serves as a key entry receptor for Coxsackie B viruses and is thought to be localised mainly within regions where contacts are formed between adjacent cells. CAR exists as at least 5 isoforms and this study has examined their expression profile and distribution in the human pancreas utilising; formalin-fixed paraffin-embedded pancreatic sections from non-diabetic individuals, type 1 diabetes patients and a human tissue microarray. Isolated human islets, human pancreatic beta and ductal cell lines were also studied. Immunological and molecular approaches were employed to examine the expression and cellular localisation of the known CAR isoforms in human pancreas. One specific isoform of CAR (CAR-SIV) with a unique C terminal PDZ binding domain, was highly expressed in human beta cells at the protein level. Surprisingly, it was distributed in a punctate manner mainly within the cytoplasm of the cells, rather than at the cell surface. In human beta cells, within the cytoplasm CAR-SIV co-localised with ZnT8, PC1/3 and insulin but less so with proinsulin suggesting that CAR-SIV is associated with insulin secretory granules. Immunogold labelling and electron microscopic analysis revealed that CAR-SIV is localised both to maturing insulin secretory granules and to fully mature, dense-core (insulin) secretory granules. Intriguingly, CAR-SIV colocalises and interacts with a cytosolic protein, PICK1, which plays a role in the budding, maturation and trafficking of insulin secretory granules. On this basis, a model is proposed whereby CAR-SIV and PICK1 interact to regulate the maturation and trafficking of insulin secretory granules. Overall, this study suggests that the specialised role and subcellular localisation of CAR-SIV in human beta cells may contribute to their sensitivity to enteroviral infection following externalisation of the protein at the cell surface, during insulin exocytosis.

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Miloudi, Hadjer. "Étude des anomalies de XPO1 dans les lymphomes B Anomalies de l’exportine 1 dans les he´mopathies malignes : des mutations au ciblage the´rapeutique Cytoplasmic cyclin D1 controls the migration and invasiveness of mantle lymphoma cells STAT6 is a cargo of exportin 1: Biological relevance in primary mediastinal B-cell lymphoma Mutant E571K and wild-type XPO1 effects are balanced in B-cell lymphoma." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMC409.

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L'exportine-1 (ou XPO1) joue un rôle clé dans le transport de nombreux ARN et près de 200 protéines cargos. La mutation « hot-spot » XPO1-E571K est présente chez près de 25% des patients atteints par le lymphome primitif du médiastin (PMBL) et la forme classique du lymphome de hodgkin (cHL), et à plus faible fréquence dans la leucémie lymphoïde chronique (LLC) (3%). Des mutations touchant la voie JAK2/STAT6 sont aussi retrouvées dans le PMBL et le cHL. C’est pourquoi nous avons étudié l’implication de XPO1 dans la voie JAK2/STAT6. Nous avons montré que STAT6 est une protéine cargo de XPO1 par les technique immunofluorescence et PLA (Proximity Ligation Assay). Nous avons montré que le traitement au selinexor induit une accumulation nucléaire de STAT6 sauvage et mutée et que STAT6 peut interagir avec les formes mutée et sauvage de XPO1.Afin de rechercher l’impact fonctionnel de la mutation E571K de XPO1 nous avons comparé plusieurs paramètres physiologiques entre les trois lignées de PMBL. Aucune différence n’a été observée. En effet, la présence de l’amplification de l’allèle sauvage dans la lignée présentant la mutation E571K (MedB1) pourrait masquer les éventuels effets de la mutation. De plus, dans la cohorte de patients que nous avons étudiée la mutation n’est jamais retrouvée à l’état homozygote ou hémizygote indiquant l’importance du dosage génique. Nos expériences de CRISPR-Cas9 sur la lignée U2940 dont le gène XPO1 est sauvage ont confirmé notre hypothèse. De manière intéressante, la présence de la mutation E571K modifie l’affinité de XPO1 pour le selinexor. En effet, le KO de l’allèle muté dans la lignée de cHL UH-01 rend les cellules moins sensibles au selinexor. Nous avons conclu que la balance entre l’allèle sauvage et l’allèle muté est un élément clé pour définir les propriétés oncogéniques de XPO1. Dans une étude préliminaire, une étude protéomique dans les lignées PMBL indique que XPO1-E571K est liée à l’importine-β1 ce qui pourrait modifier la localisation subcellulaire de XPO1.Nous avons montré que la localisation cytoplasmique de cycline D1 contrôle le mécanisme d’invasion et de migration dans cellules de lymphome à cellules du manteau (MCL). Cycline D1 étant une protéine cargo de XPO1 nous avons recherché d’éventuelles anomalies de XPO1 dans les lignées de MCL. Aucune anomalie d’expression de localisation ou de fonction de n’a été observée. Il pourrait être intéressant de déterminer la localisation subcellulaire de cycline D1 au moment du diagnostic afin de proposer une meilleure prise en charge pour les patients. De plus, bien que le selinexor soit toujours en essai clinique, son utilisation pour le traitement du MCL pourrait être envisagée dans les cas les plus agressif où cycline D1 est cytoplasmique
Exportin-1 (or XPO1) plays a key role in the nuclear export of several RNAs and more than 200 proteins. The XPO1-E571K "hot-spot" mutation is present in nearly 25% of patients with primary mediastinal B-cell lymphoma (PMBL), and the classical form of Hodgkin lymphoma (cHL) but at a lower frequency (3%) in chronic lymphocytic leukemia (CLL). Mutations affecting the JAK2/STAT6 pathway are common in PMBL and cHL. We first studied the role of XPO1 in the nuclear export of STAT6 in PMBL cell lines. Using immunofluorescence and proximity ligation assay (PLA) techniques, we showed that STAT6 is a cargo of XPO1. We also showed that a selinexor treatment induced a nuclear accumulation of wild-type and mutant STAT6 whatever the XPO1 status.In order to investigate the functional impact of the XPO1-E571K mutation, we compared several physiological parameters between the three PMBL cell lines bearing or not the mutation. No differences were observed despite the expression of the XPO1E571K allele. However, in the cell line harboring the XPO1 mutation (MedB1), the wild-type (wt) allele was amplified possibly masking the effects of the mutation. In addition, in the cohort of patients we studied, the mutation was never found in the homozygous or hemizygous state indicating the importance of the gene dosage. CRISPR-Cas9 experiments allowing the introduction of the mutation in the U2940 wt cell line confirmed our hypothesis. Interestingly, the presence of the E571K mutation changed the affinity of XPO1 for selinexor. Indeed, the knockout of the mutated allele in the cHL UH-01 line decreased its sensitivity to selinexor. We concluded that the balance between the wt and the mutated alleles is a key element in defining the oncogenic properties of XPO1. In a preliminary study, we conducted a proteomic analysis to identify XPO1E571K partners in the PMBL lines. Our results showed that XPO1E571K interacts with the importin-β1 which could modify the subcellular localization of XPO1.Mantle cell lymphoma (MCL) cells are characterized by the overexpression of cyclin D1. Cyclin D1 being an XPO1 cargo protein, we looked for possible XPO1 abnormalities in several MCL cell lines. No abnormalities in the expression, localization neither function of XPO1 were observed. But, we showed that the cytoplasmic portion of cyclin D1 controlled the invasion and migration of MCL cells. It might be interesting to determine the subcellular localization of cyclin D1 at the time of diagnosis in order to offer a better treatment management for MCL patients. In addition, although selinexor is still in clinical trials, its use for the treatment of MCL could be considered in the most aggressive cases where cyclin D1 is cytoplasmic

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Hussain, Shaista. "Signalling pathways implicated in the growth factor and cytokine mediated up regulation of gelantinase B, collagenase 1 and stromelysin-1 in rabbit aortic smooth muscle cells in vitro." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340275.

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