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1
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.
Full textAbstract:
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.
2
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.
Full textAbstract:
Master of SciencePeriodontal 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.
3
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.
Full textAbstract:
Master of SciencePeriodontal 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.
4
Hastings, William David. "Peritoneal B-2 cells comprise a distinct population that differentiates to a B-1b phenotype /." Citation, abstract and full text online, 2005. http://proquest.umi.com.ezproxy.bu.edu/pqdweb?did=913526461&sid=2&Fmt=2&clientId=374&RQT=309&VName=PQD.
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Sherwood, Tracy. "Characterization of Cannabinoid Receptor 2 Transcript Expression in B Cells." Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1767.
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Cannabinoids and cannabinoid receptors have been shown to play important roles in immune regulation particularly as modulators of anti-inflammatory cytokines and antibody production. The predominant cannabinoid receptor involved in this immune regulation is cannabinoid receptor 2 (CB2), which is robustly expressed in B cells. Utilizing a combination of bioinformatics, 5' RACE, real time RT-qPCR, and reporter assays, we showed that human B cells from peripheral blood mononuclear cells (PBMC) expressed one CB2 transcript while mouse B cells from spleen express three CB2 transcripts. Alignment of the sequenced B cell RACE products to either the mouse or human genome, along with the GenBank mRNA sequences, revealed that the transcripts isolated in this study contained previously unidentified transcriptional start sites (TSSs). In addition, expression construct testing of the genomic region containing the TSSs of the mouse CB2 exon 1 and 2 transcripts showed a significant increase of promoter activity. Bioinformatics analysis for cis-sequences in the promoter regions identified DNA binding sites for NF-kB, STAT6, and Elk1 transcription factors activated by LPS, IL-4 and anti-CD40. Regarding variations in CB2 transcript expression among the immune cell subtypes, RACE analysis showed that the exon 1b transcript is seen in B cells but not in T cells, dendritic cells or macrophages. Furthermore, RT-qPCR showed variations in transcript expression during B cell development as well as in resting versus LPS or IL-4/anti-CD40 stimulated B cells. The exon 1a transcript was predominant in pre-, immature and resting B cells whereas the exon 1b and 2 transcripts were enhanced in mature and activated B cells. These data showed for the first time that human B cells use one TSS for CB2 expression while mouse B cells use multiple TSSs for the expression of three CB2 transcripts, in which the expression of the individual transcript is related to immune cell type and/or cell activation state. Additionally, this is the first report in mouse B cells defining TSSs that are in genomic areas with promoter activity thus suggesting the location of two promoter regions. Defining the CB2 transcript expression during various stages of B cell activation provide clues to therapeutic methods.
6
Campbell, Michelle. "The immunomodulatory role of proteinase activated receptor-2 (PAR-2) in B cells." Thesis, University of the West of Scotland, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627909.
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Proteinase activated receptor-2 (PAR-2) is a seven transmembrane G protein coupled receptor (GPCR) which is activated by proteolytic cleavage to reveal a cryptic tethered ligand (Macfarlane et al, 2001). Whilst PAR-2 expression has been demonstrated in a number of immune related cells (Shpacovitch et al, 2008) and has been shown on human synovial B cells (Busso et al, 2007) however a functional role for the receptor has not been proposed. Previous studies have demonstrated the benefit of PAR-2 antagonism in inflammatory models. Utilising the antagonist ENMD-1068 as a treatment in the collagen induced arthritis (CIA) model resulted in the reduction of clinical disease severity as well as reducing the proportion of splenic B cells compared with vehicle treated mice. PAR-2 was shown to be expressed on B cell progenitors, splenic, bone marrow and peritoneal B cell subsets. Following induction of CIA this expression was up-regulated in the bone marrow Hardy fraction progenitor cells, and the innate like B cell subsets found in the peritoneum, spleen and bone marrow, consistent with up-regulated PAR-2 expression found on T cells and monocytes from patients with rheumatoid arthritis (Crilly et al, 2012b).
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Gombert, Wendy Marie. "Transcriptional regulation of the bcl-2 gene in human B cells." Thesis, King's College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312464.
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Symington, Hannah Lucy. "Mechanism of IL-2 mediated BACH2 regulation in the control of Human naive B cell differentiation into plasma cells." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1B009.
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La différenciation terminale des lymphocytes B qui se déroule dans les centres germinatifs des organes lymphoïdes secondaires est l’étape ultime de la réponse T dépendante et aboutit à la production de plasmocytes (PC) à longue durée de vie qui sécrètent des anticorps hautement affins spécifiques de l’antigène et caractéristiques de la réponse immune adaptative. La transition d’une cellule B naïve vers un PC est gouvernée par un réseau de régulation génique bien décrit et est largement influencée par l’intégration de stimuli externes qui contrôlent le devenir des cellules B tels que l’interaction BCR-antigène et les cytokines produites par les cellules T. La stimulation précoce des lymphocytes B humains activés par IL-2, induit la différenciation en PC via une signalisation ERK prolongée entraînant la baisse d’expression de BACH2, un facteur de transcription clef des cellules B. La répression transitoire de BACH2 est suffisante pour déclencher la différenciation en plasmablastes en l’absence d’IL-2, suggérant ainsi qu’il joue un rôle de « verrou moléculaire » de la différenciation en PC. Il est à noter que cette répression forcée de BACH2 aboutit à la production de plasmablastes caractérisés par un phénotype lymphoplasmocytaire. Ce travail de recherche s’est focalisé sur la caractérisation des mécanismes moléculaires régulant l’expression de BACH2 via la voie de signalisation ERK induite par IL-2. Nous avons identifié ELK-1 comme un médiateur de la répression de BACH2 par la voie IL-2/ERK, comme l’atteste sa capacité à se lier avec un élément de régulation d’un enhancer localisé dans l’intron 1 de BACH2, induisant ainsi la répression de l’enhancer et déverrouillant la différenciation en PC. La caractérisation de cet enhancer de BACH2 a confirmé qu’il est régulé de manière dynamique au cours de la différenciation terminale B et qu’il est localisé dans une région sujette aux mutations suggérant qu’il pourrait être impliqué dans la lymphomagenèseThe terminal differentiation of B cells, which takes places within germinal centres of secondary lymphoid organs, is the ultimate step of a T cell dependent response and results in the generation of long-lived plasma cells (PCs) that secrete protective, antigen-specific, high-affinity antibodies as part of adaptive immunity. The transition of a naive B cell into a PC is governed by a well-characterised gene regulatory network and is heavily influenced by the integration of externally received signals, including BCR-antigen binding and T cell help, such as cytokines which guide B cell fate. The early IL-2 priming of human primary activated B cells triggers PC differentiation through sustained ERK signalling resulting in the down regulation of B cell transcription factor BACH2. Transient BACH2 repression is sufficient to trigger plasmablast differentiation in the absence of IL-2 suggesting that it acts as a key lock of PC differentiation. Importantly, this enforced BACH2 repression results in the generation of plasmablasts with a lymphoplasmacytic phenotype. The focus of this thesis was to characterise the molecular mechanisms regulating BACH2 expression via the IL-2 ERK transduction pathway. We identify ELK-1 as the mediator of IL-2 ERK induced BACH2 downregulation as it binds to a regulatory enhancer element located within intron 1 of BACH2 instigating its repression and unlocking the PC programme triggering differentiation. The characterisation of this BACH2 enhancer confirms that it is dynamically regulated during PC differentiation and is located within a region targeted for mutation suggesting that it may have a potential role in lymphomagenesis
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Ceizar, Maheen. "B-cell Lymphoma-2 (Bcl-2) Is an Essential Regulator of Adult Hippocampal Neurogenesis." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23287.
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Of the thousands of dividing progenitor cells (PCs) generated daily in the adult brain only a very small proportion survive to become mature neurons through the process of neurogenesis. Identification of the mechanisms that regulate cell death associated with neurogenesis would aid in harnessing the potential therapeutic value of PCs. Apoptosis, or programmed cell death, is suggested to regulate death of PCs in the adult brain as overexpression of B-cell lymphoma 2 (Bcl-2), an anti-apoptotic protein, enhances the survival of new neurons. To directly assess if Bcl-2 is a regulator of apoptosis in PCs, this study examined the outcome of removal of Bcl-2 from the developing PCs in the adult mouse brain. Retroviral mediated gene transfer of Cre into adult floxed Bcl-2 mice eliminated Bcl-2 from developing PCs and resulted in the complete absence of new neurons at 30 days post viral injection. Similarly, Bcl-2 removal through the use of nestin-induced conditional knockout mice resulted in reduced number of mature neurons. The function of Bcl-2 in the PCs was also dependent on Bcl-2-associated X (BAX) protein, as demonstrated by an increase in new neurons formed following viral-mediated removal of Bcl-2 in BAX knockout mice. Together these findings demonstrate that Bcl-2 is an essential regulator of neurogenesis in the adult hippocampus.
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Stein, Merle [Verfasser], and Hans-Martin [Gutachter] Jäck. "A defined mitochondrial metabolic state in pre-B cells contributes to B cell homeostasis and is modulated by Swiprosin-2 / EFhd1 / Merle Stein ; Gutachter: Hans-Martin Jäck." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2016. http://d-nb.info/1114989932/34.
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Stein, Merle Verfasser], and Hans-Martin [Gutachter] [Jäck. "A defined mitochondrial metabolic state in pre-B cells contributes to B cell homeostasis and is modulated by Swiprosin-2 / EFhd1 / Merle Stein ; Gutachter: Hans-Martin Jäck." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2016. http://d-nb.info/1114989932/34.
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Karlsson, Hannah. "CD19-targeting CAR T Cells for Treatment of B Cell Malignancies : From Bench to Bedside." Doctoral thesis, Uppsala universitet, Klinisk immunologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-232638.
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Immunotherapy for cancer is a young research field progressing at high speed. The first chimera of an antibody and a signaling chain was designed by Zelig Eshhar and was later further developed to enhance existing T cell therapy by combining a single-chain fragment of an antibody with the CD3 zeta chain of the TCR complex. T cells expressing these chimeric antigen receptors (CARs) could recognize and specifically kill tumor cells. However the T cells, lacked in persistence and tumor rejection did not occur. Thus, the CAR constructs have been improved by providing the T cell with costimulatory signals promoting activation. The focus of this thesis has been to evaluate second and third generation αCD19-CAR T cells for the treatment of B cell leukemia and lymphoma. B cell tumors commonly upregulate anti-apoptotic proteins such as Bcl-2, which generates therapy resistance. In the first paper a second generation (2G) αCD19-CD28-CAR T cell was combined with the Bcl-2 family inhibitor ABT-737. ABT-737 sensitized tumor cells to CAR T cell therapy and may be an interesting clinical combination treatment. In paper II, the phenotype and function of a third generation (3G) αCD19-CD28-4-1BB-CAR T cell were evaluated. B cell-stimulated CAR T cells showed increased proliferation and an antigen-driven accumulation of CAR+ T cells. 3G CAR T cells had equal cytotoxic capacity, similar lineage, memory and exhaustion profile phenotype compared to 2G CARs. However, 3G CAR T cells proliferated better and had increased activation of intracellular signaling pathways compared to 2G CAR T cells. In paper III, αCD19-CD28-4-1BB-CAR T cells were used to stimulate immature dendritic cells leading to an upregulation of maturation markers on co-cultured dendritic cells. Hence, CAR T cells may not only directly kill the tumor cells, but may induce bystander immunity that indirectly aids tumor control. This thesis also include supplementary information about the development and implementation of protocols for GMP production of CAR T cell batches for a phase I/IIa clinical trial currently ongoing for patients with refractory B cell leukemia and lymphoma. So far, two patients have safely been treated on the lowest dose.
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Janani, Ramesh. "B cell development and death in mouse bone marrow : effect of a bcl-2 transgene and Iprgld mutations on in vivo dynamics and localisation of precursor B cells." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34647.
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The possible roles of the anti-apoptotic protein, Bcl-2, and pro-apoptotic Fas receptor-ligand interactions in cell death decisions during the development of B lymphocytes in mouse bone marrow and their maturation in the spleen have been evaluated in gene-modified and mutant mice.In Emu-bcl-2 transgenic mice, the population dynamics and tissue organisation of phenotypically defined precursor B cells, have been evaluated by immunofluorescence labeling, mitotic arrest, BrdU uptake, flow cytometry and in vivo radioimmunolabeling combined with light and electron microscope radioautography. In bone marrow of Emu-bcl-2 mice, the number and production rate of proliferating precursor B cells were increased. Immature B lymphocytes also increased in number, accumulating extravascularly around the central venous sinus, and the total rate of production of these rapidly-renewed IgM + B cells was increased. Phenotypically mature B lymphocytes and B lymphocytes having a slow turnover rate greatly increased in number. Many mature B cells were located within the lumen of venous sinusoids and in perisinusoidal locations. In the spleen, the usual population of rapidly-renewed IgM + B cells was undetectable. In contrast, both slowly renewing B cells and a further stable population of very long-lived B cells were greatly increased in numbers but had unchanged longevity. The rates of apoptosis among B cell subsets in short term bone marrow cultures from bcl-2 transgenic mice were reduced, while bcl-2/scid mice accumulated many B220+mu- pro-B cells in bone marrow. The results indicate that overexpression of bcl-2 inhibits apoptosis during B cell development in bone marrow and promotes survival of newly-formed B cells in the spleen and their entry into a long-lived recirculating B cell pool.
In Ipr and gld mutant mice lacking functional Fas and Fas ligand, respectively, pre-B cells were increased in number and production rate in bone marrow, while in spleen, in addition to an increase in number of mature B cells, a population of B220+mu - cells was expanded. Thus, Fas ligation may contribute to B cell death in bone marrow.
The findings suggest that Bcl-2 and Fas can help to regulate the developmental stage-specific apoptosis of B cells designed to prevent the persistence of nonfunctional, preneoplastic or autoreactive cells.
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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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Janani, Ramesh. "B cell development and death in mouse bone marrow, effect of a bcl-2 transgene and lpr/gld mutations on in vivo dynamics and localisation of precursor B cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ36988.pdf.
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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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Osei-Twum, Jo-Ann B. "Contribution of p-glycoprotein mediated-efflux to the epithelial transport of amphotericin b in caco-2 cells." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46529.
Full textAbstract:
Background:
Amphotericin B (AmB) is a highly efficacious therapeutic for invasive fungal infections (IFIs) and protozoal diseases. Increasing prevalence of these conditions necessitates the development of an oral AmB formulation, with reduced toxicity, improved tissue distribution, and improved affordability. Efflux transporters, such as the ABCB1 gene product P-glycoprotein (P-gp), affect the oral bioavailability and disposition of a diverse range of compounds. It remains to be ascertained whether AmB is a substrate of P-gp mediated efflux. Therefore, the objective of this study was to determine whether P-gp contributes to the epithelial transport of AmB in the enterocyte-like Caco-2 cell model.
Methods:
Transient knockdown of ABCB1 was achieved in Caco-2 cells using small interfering RNA. The effect of this knockdown on Caco-2 cell differentiation, transporter expression, and P-gp function were investigated using the measurement of trans-epithelial electrical resistance, Western blot analysis, bi-directional transport and accumulation of Rhodamine 123, a fluorescent P-gp substrate. The interaction between AmB and P-gp was examined using a P-gp ATPase activity and a LDH assay. The ABCB1 transient knockdown Caco-2 cell model and a cell-based AmB HPLC-UV assay were employed to quantify AmB cellular association.
Results:
Transfected and non-transfected Caco-2 cells formed confluent and differentiated monolayers. Transient knockdown of ABCB1 reduced P-gp expression and efflux efficiency by approximately 63% compared to non-transfected cells. AmB did not stimulate P-gp ATPase activity and AmB cytotoxicity did not differ between transfected and non-transfected cells. Increased association of AmB was demonstrated for ABCB1 siRNA transfected cells compared to non-transfected cells, at the highest tested AmB concentration (5 μg/mL).
Conclusions:
Small interfering RNA is a possible alternative to the physical inhibition of P-gp, as the transient knockdown of ABCB1 in Caco-2 cells decreased P-gp expression and function. Although there was an increased cellular association of AmB with ABCB1 siRNA transfected cells, differences were not observed for P-gp ATPase activity or between AmB cytotoxicity profiles. The data suggested that P-gp has a minimal contribution to the epithelial transport of AmB in Caco-2 cells.
Significance:
Clinically, it is unlikely that the oral bioavailability and drug disposition of AmB will be affected by P-gp mediated efflux.
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Arima, Hiroshi. "B cells with aberrant activation of Notch1 signaling promote Treg and Th2 cell-dominant T cell responses via IL-33." Kyoto University, 2019. http://hdl.handle.net/2433/236612.
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Pritts, Timothy A. "NUCLEAR FACTOR-KAPPA B ACTIVATION IN THE ENTEROCYTE AND INTESTINAL MUCOSA: REGULATION BY THE HEAT SHOCK RESPONSE AND PROTEASOME INHIBITORS." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin990705885.
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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.
Full textAbstract:
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.
Full textAbstract:
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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Saturno, Juvaní Lago. "Análise imuno-histoquímica da Bcl-2, Bcl-6, c-Myc e ciclina D1 em linfomas de células B da região oral." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/23/23141/tde-06082014-144841/.
Full textAbstract:
Neste trabalho foram analisados 30 casos de linfomas de células B da região oral, fixados em solução de formaldeído e incluídos em parafina, através da técnica de imuno-histoquímica para as proteínas c-Myc, Bcl-2, Bcl-6 e ciclina D1. Dos casos analisados 40% foram positivos para a marcação para c-Myc, 33,3% para a marcação para ciclina D1, 83,3% para a marcação para Bcl-2 e 53,3% para a marcação para Bcl-6. Todos os casos foram diagnosticados como linfomas difusos de grandes células B, o subtipo de linfoma com a maior casuística. A análise destas proteínas é de fundamental importância para o diagnóstico e direcionamento do tratamento de doenças hematopoiéticas, pois estão envolvidas em vários processos de controle da transcrição gênica, do ciclo celular e dos processos apoptóticos e o aumento do conhecimento sobre sua ação em diferentes subtipos de linfomas pode corroborar outros estudos.In this study, 30 cases of formalin-fixed and paraffin-embedded B-cell lymphomas of the oral region were submitted to immunohistochemistry for the detection of proteins c-Myc, Bcl-2, Bcl-6 and cyclin D1. Fourty percent (40%) of the studied cases were positive for c-Myc, 10% for cyclin D1, 83.3% for Bcl-2 and 53.3% for Bcl-6. The analysis of these proteins has fundamental importance for the diagnosis and treatment course of hematopoietic diseases, because they are involved in various processes controlling gene transcription and cell cycle. All cases were diffuse large B-cell lymphomas, the subtype with the highest incidence. The analysis of these proteins is very important for the diagnosis and treatment course of hematopoietic diseases, because they are involved in various processes controlling gene transcription, cell cycle and apoptotic processes and an increase in the knowledge of their action in different subtypes of lymphomas can corroborate to other studies.
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Padro, Caroline Jeannette. "A Study of the Distal Molecular Mechanism by which Beta-2 Adrenergic Receptor Stimulation on a B Cell Regulates IgE Production." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1384763500.
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Xu, Chenjia. "A Novel in vitro PDE7 Inhibitor Inhibits IL-2 Gene Expression in Activated T Cells and Induces Apoptosis in a B-cell Line and Monocytic Cell Line." Thesis, Boston College, 2013. http://hdl.handle.net/2345/3935.
Full textAbstract:
Thesis advisor: Thomas C. ChilesElevating intracellular cAMP levels can result in a wide range of anti-inflammatory effects and growth arrest and apoptosis in cancer cells, marking phosphodiesterases (PDEs) as potential targets for inflammatory diseases and cancer treatment. PDE7A is proposed to be a new therapeutic target for its ubiquitous expression in proinflammatory and immune cells. A Barbituric acid based compound, BC12 was identified as an in vitro PDE7 inhibitor in fission-yeast-based high-throughput screen. Analysis of this compound on the activation of Jurkat T lymphocytes, mouse and human primary T cells reveals inhibition of IL-2 production, though cell viability is not significantly impacted. Real-time RT-PCR and mRNA stability assays indicate that the inhibition of IL-2 production by BC12 is attributable to transcriptional repression without accelerating IL-2 mRNA decay. By contrast, compounds of similar structure with that of BC12 exhibit varying effects on IL-2 production that does not correlate with their in vitro PDE7 inhibitory activity, suggesting that the in vivo target of BC12 responsible for these effects may not be PDE7. Our study further reveals that BC12 inhibits IL-2 transcription through targeting NFAT and NFkB-mediated pathways. Preliminary investigation on other T helper cell cytokine secretion indicates that BC12 has a potential to selectively inhibit Th2 cytokines. Our data suggest that BC12 may present a novel anti-inflammatory drug for its immunosuppressive and potential immunomodulatory effects. Analysis of BC12 on a human B-cell line and a monocytic cell line demonstrate its pro-apoptotic effects in a dose-dependent manner. Titration of BC12 on human diffuse large B-cell lymphoma (DLBCL), LY18 cells, and human primary B cells reveals that BC12 induces cell death more effectively in DLBCL LY18 cells than normal B cells, suggesting the anti-cancer potential of this compound
Thesis (PhD) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
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Othman, Siti Sarah. "Interactions of an attenuated AroA-derivative of Pasteurella multocida B:2 with mammalian cells and its potential for DNA vaccine delivery." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2905/.
Full textAbstract:
The primary aim of this study was to investigate the potential of an aroA mutant of Pasteurella multocida B:2 (vaccine strain JRMT12) as a candidate for DNA vaccine delivery (bactofection). First, the invasive property of the vaccine strain was assessed for its interaction with different mammalian cell lines. Next, a eukaryotic expression plasmid that could be maintained in Pasteurella was modified to contain a prokaryotic reporter gene to help in determining the location and viability of the bacteria when moving from the extracellular environment into the intracellular compartment of the mammalian cells. This plasmid was further developed to function with a dual prokaryotic and eukaryotic reporter system in order to demonstrate expression of the plasmid DNA in the mammalian cells. During interaction of strain JRMT12 with mammalian cell lines, the ability of the bacterium to adhere, invade and survive intracellularly was monitored and assessed. Three mammalian cell lines were used: a mouse macrophage-like cell line, J774.2; a bovine-lymphoma cell line, BL-3; and an embryonic bovine lung cell line, EBL. The JRMT12 strain was compared with strains of the wild-type P. multocida B:2 (85020), bovine P. multocida A:3, Mannheimia haemolytica A:1 and Escherichia coli XL-1 BLUE. Both P. multocida B:2 strains were capable of adhering to and invading J774.2, BL-3 and EBL cells. All of the Pasteurella and Mannheimia strains tested were able to adhere to EBL cells but only B:2 strains were taken up intracellularly in significant numbers. The vaccine strain, JRMT12 was found to survive intracellularly in EBL cells for at least 7 h although a steady decline in the number of viable intracellular bacteria was noted with time. In an invasion inhibition assay, the use of the microfilament formation inhibitor cytochalasin D suggested that the entry into mammalian cells was by an actin-dependent process. Cell viability assessment by trypan blue staining indicated that none of the bacterial strains was toxic for the mammalian cells. Upon entry into the mammalian cells the JRMT12 strain resided in a vacuolar compartment, as demonstrated by transmission electron microscopy. However, P. multocida A:3 and M. haemolytica A:1 were only found loosely adhering to the cell surface of EBL cells and were not detected intracellularly. Further morphological assessment by TEM showed that only a low percentage of mammalian cells appeared to contain one or more JRMT12, suggesting that only certain cells in the population were capable of being invaded by, or taking up, the bacteria. Attempts were made to construct a Pasteurella eukaryotic expression plasmid using a gene sequence from the Pasteurella shuttle plasmid pAKA16, developed previously in this laboratory, and the commercial eukaryotic expression plasmid pCMV-sCRIPT, but these were only partially successful. The origin of replication gene (oriP) in the Pasteurella shuttle plasmid was isolated and sequenced. Analysis of oriP showed sequence similarity with the known origins of replication in other Pasteurella plasmids. The E. coli plasmid origin of replication (oriE) was removed from pCMV-sCRIPT and the oriP gene was ligated into the oriE-free pCMV-sCRIPT but attempts to transform the resulting plasmid into P. multocida B:2 were not successful. An alternative approach to plasmid development was made using another commercial eukaryotic expression vector, pEGFP-N1. This plasmid has the same properties as pCMV-sCRIPT but has an additional, fluorescent reporter gene under the control of a eukaryotic promoter. It was found to be able to replicate in P. multocida B:2 but positive transformants were only recovered after prolonged incubation after electroporation. The plasmid was stably maintained in strain JRMT12 for at least 14 days with or without antibiotic selection. It was also successfully transfected into EBL cells, as shown by expression of green fluorescent protein (GFP) in individual cells. The P. multocida vaccine strain JRMT12 was also able to deliver the plasmid into EBL cells, although the number of EBL cells expressing GFP after bacterial delivery was lower than by direct transfection of the plasmid. Next, plasmid pMK-Express, a Pasteurellaceae prokaryotic expression vector with a gfp reporter gene, was used. When this was electroporated into the vaccine strain, the strain was shown to express GFP maximally as measured by fluorimetry, during the early exponential phase of bacterial growth. The DsRed.M1 gene coding for red fluorescent protein (RFP) from plasmid pDsRed-Monomer was then used to replace the gfp gene in pMK-Express to make the construct pMK-RED. After electroporation of pMK-RED into the JRMT12, RFP expression was detected maximally during the early exponential phase of bacterial growth. The same strain expressing RFP could also be detected in the intracellular compartment of the EBL cells by fluorescence microscopy at 3 h post-invasion. Finally, plasmid pSRG, our so-called “traffic light” plasmid with a dual reporter system was constructed. This was made from plasmid pEGFP-N1 (with its existing eukaryotic expression system for GFP expression) and the sodRED fragment (with a Pasteurella promoter controlling the DsRED.M1 gene for RFP expression) isolated from plasmid pMK-RED. This plasmid was stable in strain JRMT12 with or without antibiotic selection for 14 passages. RFP expression from JRMT12 was detected maximally during the early exponential phase of bacterial growth. Transfection of pSRG into EBL cells gave individual cells expressing GFP. Invasion assays with EBL cells and P. multocida B:2 JRMT12 pSRG+ showed that RFP-expressing bacteria could be detected intracellularly at 3 h post-invasion. At this stage, some EBL cells harbouring RFP-expressing bacteria were observed to express GFP simultaneously. At 5 h post-invasion, some of the EBL cells were still harbouring RFP-expressing bacteria and at the same time expressing GFP themselves. Concurrently, some Pasteurella free-EBL cells were shown to express GFP. These experiments proved the functionality of the pSRG dual reporter system and the potential of P. multocida B:2 JRMT12 for bactofection and delivery of a DNA vaccine. An apparent immunosuppressive effect of P. multocida B:2 on the proliferative response to concanavalin A (ConA) of peripheral blood mononuclear cells (PBMC) had been reported by Ataei (2007). The PBMC had been taken from calves infected with P. multocida B:2 or from normal calves and treated in vitro with extracts of P. multocida B:2. In the present study, in vitro assays with PBMC from normal calves were undertaken in an attempt to confirm these findings. A cell-free extract (CFE) of the vaccine strain JRMT12 was found to suppress the subsequent proliferation of PBMC in response to ConA in a dose-dependent manner. However, the results were not consistently reproducible and the same effect could not be demonstrated with CFE from the wild-type strain 85020.
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Li, Qian [Verfasser], and Mengji [Akademischer Betreuer] Lu. "Toll-like receptor 2/7 activation enhances the metabolism and functions of CD8+ T and B cells / Qian Li ; Betreuer: Mengji Lu." Duisburg, 2020. http://d-nb.info/1209877619/34.
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Lyman, Rachel C. "Cell cycle control and its modulation in HPV infected cells." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/863.
Full textAbstract:
A key effect of human papillomavirus (HPV) infection is to disrupt the normal cell cycle in order to subvert the cellular DNA replication machinery. Morphologically, condylomata induced by high and low risk HPV types cannot be distinguished and many studies have shown that the pattern of viral gene expression is similar in condylomata caused by both high risk and low risk HPV types. Detailed morphological study of cell cycle protein expression has not previously been performed on condylomata infected with low risk HPV types. The findings presented suggest that the mechanisms employed by low risk HPV6 or HPV11 to subvert cellular functions in condylomata acuminata are similar to those employed by high risk HPVs, with the exception of cyclin D1 and p53 protein over-expression. The differences in p53 expression and cyclin D1 expression seen between high and low risk HPV infection, reflect the known differences between high and low risk types and are in agreement with the known differences between high risk and low risk E6 and E7 proteins. PHK transduction studies demonstrated HPV E6 and E7 induce changes in cell cycle protein expression and that there are differences in cell cycle abrogation between HPV6 and HPV16. Disruption of the p53-MDM2 interaction can lead to activation of the p53 pathway. HPV infected lesions almost always contain wild-type p53. The binding of HPV E6 to p53, and its subsequent targeting for degradation, prevents activation of the p53 pathway in HPV infected cells. Cells over expressing HPV genes were treated with Nutlin-3, a MDM2-small molecule antagonist. The findings presented suggest treatment with Nutlin-3 induces cell cycle arrest in cells expressing HPV16 E7 and HPV6 E6 and HPV6 E7. This suggests a potential role for Nutlin-3 in the treatment of HPV infected cells.
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Fuchs, Iris Judith. "Untersuchungen zur chemischen Transformation von intestinalen Epithelzellen der Ratte und des Menschen durch 2-Hydroxyamino-1-methyl-6-phenylimidazo(4,5-b)pyridin." Phd thesis, Universität Potsdam, 2006. http://opus.kobv.de/ubp/volltexte/2007/1180/.
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Golumba-Nagy, Viktória [Verfasser], Thomas [Gutachter] Wunderlich, and Hamid [Gutachter] Kashkar. "CAR modified T cells resist TGF-b mediated repression through engineered IL-7 triggered IL-2 signaling / Viktória Golumba-Nagy ; Gutachter: Thomas Wunderlich, Hamid Kashkar." Köln : Universitäts- und Stadtbibliothek Köln, 2019. http://d-nb.info/1188406531/34.
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Neil, Jason Robert. "TGF-ß promotes cancer progression through the xIAP:TAB₁:TAK₁:IKK axis in mammary epithelial cells /." Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2008.
Find full textAbstract:
Thesis (Ph.D. in Pharmacology) -- University of Colorado Denver, 2008.Typescript. Includes bibliographical references (leaves 117-147). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Tang, Kai Dun. "Dissecting the prostate cancer stem cell niche inside the bone marrow." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/88935/1/Kai%20Dun_Tang_Thesis.pdf.
Full textAbstract:
Prostate cancer frequently metastasizes to bone, which becomes incurable; yet how cancer cells manage to migrate and grow inside the bone remains unknown. In this study I have discovered that both bone and fat cells within the bone marrow actively promote the survival and expansion of prostate cancer cells, and have subsequently developed approaches that can effectively inhibit these processes. Therefore, my work offers opportunities for the development of new prognostic and therapeutic approaches against metastatic prostate cancer and have the potential for improving the treatment outcome of the patients.
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Zhou, Xiaodan [Verfasser]. "Investigations on the effects of peroxisome proliferator-activated receptors and of nuclear factor kappa B on novel organic cation transporter 2 and carnitine uptake in bovine kidney cells / Xiaodan Zhou." Gießen : Universitätsbibliothek, 2014. http://d-nb.info/106859151X/34.
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FLORIO, DANIEL Z. de. "Analise de eletrolitos de ZrO sub(2):Y sub(2) O sub(3) + B sub(2) O sub(3) e de eletrodos de La sub(0,8) Sr sub(0,2) Co sub (0,8) Fe sub (0,2) O sub (3-delta) por espectroscopia de impedancia." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11130.
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Made available in DSpace on 2014-10-09T12:48:42Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:59:46Z (GMT). No. of bitstreams: 1 09305.pdf: 5404217 bytes, checksum: 19eda8ad49f8cd247304fef0fb69c1bc (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Burén, Jonas. "Glucose and lipid metabolism in insulin resistance : an experimental study in fat cells." Doctoral thesis, Umeå universitet, Institutionen för folkhälsa och klinisk medicin, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-26.
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Type 2 diabetes is usually caused by a combination of pancreatic β-cell failure and insulin resistance in target tissues like liver, muscle and fat. Insulin resistance is characterised by an impaired effect of insulin to reduce hepatic glucose production and to promote glucose uptake in peripheral tissues. The focus of this study was to further elucidate cellular mechanisms for insulin resistance that may be of relevance for type 2 diabetes in humans. We used rat and human adipocytes as an established model of insulin’s target cells. Glucocorticoids, e.g. cortisol, can induce insulin resistance in vivo. In the present study, pretreatment of rat adipocytes in vitro for 24 h with the cortisol analogue dexamethasone produced a downregulation of glucose uptake capacity as well as a marked depletion of cellular insulin receptor substrate 1 (IRS-1) and protein kinase B (PKB), two proteins suggested to play a critical role in the intracellular signal transduction pathway of insulin. The amount of phosphorylated PKB in response to acute insulin treatment was decreased in parallel to total PKB content. The basal rate of lipolysis was enhanced, but insulin’s antilipolytic effect was not consistently altered following dexamethasone pretreatment. Alterations in blood glucose as well as insulin levels may be of great importance for cellular as well as whole-body insulin resistance. High glucose (≥15 mM) for 24 h induced a decrease in glucose uptake capacity in rat adipocytes and IRS-1 content was reduced whereas IRS-2 was increased. Long-term pretreatment with a high insulin concentration downregulated insulin binding capacity and when combined with high glucose, it produced a pronounced reduction of cellular IRS-1 and 2 content together with insensitivity to insulin’s effect to activate PKB and a decrease in glucose uptake capacity. A common denominator for a decrease in glucose uptake capacity in our rat adipocyte studies seems to be a decrease in IRS-1 content. Adipocytes from type 2 diabetes patients are insulin-resistant, but in our work the insulin resistance could be reversed by incubation of the cells at a physiological glucose level for 24 h. Insulin resistance in fresh adipocytes from type 2 diabetes patients was associated with in vivo insulin resistance and glycemic level and with adipocyte cell size and waist-hip ratio (WHR). As a potential mechanism for postprandial dyslipidemia in type 2 diabetes, we examined the nutritional regulation of subcutaneous adipose tissue lipoprotein lipase (LPL) activity. It was upregulated by ~40-50 % after a standardised lipid-enriched meal and this was very similar in type 2 diabetes patients and control subjects, suggesting that the postprandial hypertriglyceridemia found in type 2 diabetes is not explained by an altered nutritional regulation of LPL in subcutaneous fat. In conclusion, the present work provides evidence for novel interactions between glucocorticoids and insulin in the regulation of glucose metabolism that may potentially contribute to the development of insulin resistance. High levels of glucose and insulin produce perturbations in the insulin signalling pathway that may be of relevance for human type 2 diabetes. Cellular insulin resistance may be secondary to the diabetic state in vivo, e.g. via glucotoxicity. This is supported by our finding that insulin resistance in adipocytes from type 2 diabetes patients can be reversed after incubation at a physiological glucose level. Key words: adipocyte, insulin resistance, type 2 diabetes, insulin signalling, glucose uptake, insulin, glucose, dexamethasone, insulin receptor substrate, protein kinase B, GLUT4, lipoprotein lipase.
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Zhang, Lu. "IgG3 Complements IgM in the Complement-Mediated Regulation of Immune Responses." Doctoral thesis, Uppsala universitet, Institutionen för medicinsk biokemi och mikrobiologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-316618.
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An intact complement system is essential for the initiation of a normal antibody response. Antibodies can regulate their own production against the antigens that they are specific for. Both IgG3 and IgM are able to enhance the antibody response via complement. Here, we have compared the fate of OVA-TNP (ovalbumin-2,4,6-trinitrophenyl) administered intravenously to mice either alone or in complex with monoclonal IgG3 anti-TNP. IgG3-antigen complexes bind to marginal zone (MZ) B cells via complement receptors 1 and 2 (CR1/2) and are transported into splenic follicles. The majority (50% - 90%) of the antigens is deposited on follicular dendritic cells (FDC) and the antigen distribution pattern is strikingly similar to peripheral dendrites/processes of FDC already 2 h after immunization. The development of germinal centers (GC) induced by IgG3-antigen complexes is impaired in mice lacking CR1/2. Experiments on bone marrow chimeric mice show that CR1/2 expression on both MZ B cells and FDC is required for optimal IgG3-mediated enhancement of antibody responses. Complement factors C3 and C1q are essential for OVA-TNP delivery and deposition on splenic FDC. The production of IgG anti-OVA is abrogated in mice lacking CR1/2, C1q, and C3. Further, IgG3-antigen complexes dramatically upregulate the memory response against OVA-TNP by inducing OVA-specific memory cells. Besides small protein OVA, IgG3 can also upregulate humoral responses against large soluble keyhole limpet hemocyanin. To further study the role of MZ B-cells and CR1/2 in enhancement of antibody responses, a knock-in mouse strain, Cμ13, was used. IgM in this mouse strain is unable to activate complement due to a point mutation in the constant µ-heavy chain. Cμ13 mice have a higher proportion of MZ B cells, with higher CR1/2 expression, than wild-type mice. More IgG3-immune complexes are captured by MZ B cells and deposited on FDC in Cμ13 than in WT mice. In spite of this, IgG3 did not enhance the primary antibody response more efficiently in Cμ13 mice. The existence of endogenous IgM-mediated feedback regulation was suggested by the observation that GC development and antibody responses, after priming and boosting with suboptimal doses of SRBC, was lower in Cμ13 than in WT mice.
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Santos, da Silva Eveline. "Rôle des polymorphismes dans la région C-Terminale de l'enveloppe du VIH dans l'infection de cellules primaires." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0279/document.
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Le virus de l'immunodéficience humaine (VIH) est responsable du syndrome d'immunodéficience humaine acquise (SIDA). Le virus est très variable et est classé en divers sous-types dont le sous-type B qui est le plus étudié et le C qui est le plus répandu. L'enveloppe (Env) à la surface du virus lui permet d'infecter des cellules du système immunitaire, parmi lesquelles les lymphocytes T CD4 (LT CD4) et les macrophages sont des cibles privilégiées. Nous avons étudié le rôle de variations de séquences dans la partie de Env qui n'est pas exposée à la surface du virus (la queue intravirale (gp41CT)). Nos résultats montrent que ce domaine contribue à la réplication du virus dans les LT CD4 et que des variations dans ce domaine entravent l'assemblage des protéines de structure du virus, diminuant la production de nouveaux virus. Ce défaut n'est pas observé dans les macrophages, suggérant qu'un facteur cellulaire est impliqué. Identifier ce facteur pourrait fournir de nouvelles cibles antiviralesThe human immunodeficiency virus (HIV) is responsible for the pandemic of acquired immunodeficiency syndrome (AIDS). Being highly variable, the virus has been subdivided into viral subtypes. Subtype B is the most studied, while subtype C is the most spread. The envelope (Env) expressed at the surface of the virion enables infection of cells involved in the immune system, like CD4 cells (CD4 TL) and macrophages. We studied the Env region not exposed at the viral surface (intraviral tail, gp41CT), which also harbors sequence characteristics linked to viral subtype. Viruses with subtype C gp41CT had lower replication capacities in CD4 TL. Microscopy analysis showed a defect in clustering of the viral structural protein Gag, revealing that changes in gp41CT affect assembly of all viral components. This defect was seen in CD4 TL but not in macrophages, suggesting the involvement of a cellular factor. Identifying this factor could open new therapeutic leads
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Ristow, Gerhard. "Immunophänotypisierung des entzündlichen Infiltrates der Arthrose assoziierten Synovialitis." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2003. http://dx.doi.org/10.18452/14856.
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Die Entzündungsreaktion der Arthrose wird als eine sekundäre Reaktion auf einen degenerativen Prozeß des Gelenkknorpels angesehen. Die Ursache für die Degeneration kann im Mißverhältnis zwischen Belastbarkeit und Beanspruchung liegen, es können metabolische Störungen (Urämie, Diabetes mellitus) verantwortlich gemacht werden, weswegen von sekundärer Arthrose gesprochen wird. Die Ursache der primären Arthrose bleibt unbekannt. Es kann als bewiesen angesehen werden der Zusammenhang mit Alter und Geschlecht der Patienten, denn Arthrose ist in der Regel eine Erkrankung jenseits des fünfzigsten Lebensjahres und betrifft vornehmlich Frauen. In der vorliegenden Arbeit wurde die Synovialis von 20 Patienten aufgearbeitet und hinsichtlich des enthaltenen entzündlichen Infiltrates untersucht. Unter Anwendung der indirekten Immunperoxidase Technik und der indirekten Immunfluoreszenz Technik wurde die Expression der Antigene CD 20, CD 23, CD 40, CD 27, IgG, IgA, IgM, Kappa, Lambda, CD 3, CD 4, CD 8, Ki M4, CD 68, Ki 67 sowie die Expression der Cytokine IL 2 und IL 10 analysiert. Die Synovialmembran zeigte histologisch eine Verbreiterung der Deckzellschicht, Knorpelfragmente innerhalb der Synovialmembran und ein insgesamt schwach ausgeprägtes entzündliches Infiltrat. In lediglich drei von 20 Fällen fand sich eine stärkere entzündliche Infiltration. Diese entzündlichen Infiltrate wiesen eine perivaskuläre Verteilung auf. Am häufigsten wurden in gefäßnahen Regionen B Lymphozyten identifiziert, Plasmazellen wiesen in der Regel einen deutlich größeren Abstand zum Gefäß auf. Unter den nachgewiesenen Plasmazellen fand sich eine prädominante Expression an IgG bei ausgewogener Anwesenheit sowohl der Kappa- als auch der Lambda- Leichtketten. T Lymphozyten waren ebenfalls zirkulär um die Gefäße anzutreffen und zeigten eine prädominante Interleukin 10 Expression. Lymphozytäre Aggregate, mit follikelähnlicher Struktur ließen sich in lediglich in 4 von 20 Fällen nachweisen. Makrophagen waren sowohl perivaskulär als auch in der Deckzellschicht nachweisbar. Ki M4 positive Retikulumzellen (FDC) waren dagegen nur in einem von 20 Fällen nachweisbar. Alle Zellpopulationen der Membrana synovialis wiesen nur eine schwache Proliferationsaktivität auf. Das Fehlen von dem Keimzentrum des Lymphfollikels vergleichbaren Strukturen, die deutliche Abwesenheit von Ki M4 positiver FDC's sowie die schwache Expression von Ki 67, sprechen trotz Anwesenheit der ebenfalls zur Antigenpräsentation befähigten Makrophagen gegen eine Einwanderung und Maturation nativer B Lymphozyten in die Membrana Synovialis. Wandern dagegen Gedächtniszellen in die Membrana synovialis ein, so ist eine Maturation mit Follikelbildung nicht mehr notwendig. Unter der Mithilfe von T Lymphozyten und Makrophagen können die B Lymphozyten zu Plasmazellen differenzieren. T Lymphozyten zeichnen sich ebenfalls durch eine starke perivaskuläre Verteilung aus. Dabei ist die Expression von IL 10 prädominant, was sich als eine Immunantwort von TH2-Typus interpretieren läßt. Diese ermöglicht eine Differenzierung der B Lymphozyten zu Plasmazellen. Reife B Lymphozyten, die unter dem Einfluß einer TH2 Subpopulation von CD 4 positiven T Lymphozyten ohne Keimzentrum zu Plasmazellen differenzieren, könnten ein Grund dafür sein, daß follikuläre Strukturen fehlen. Vorgereifte B Lymphozyten benötigen auch keine inflammatorisch hochpotenten Zytokine um eine schnelle Reifung und eine Immunantwort zu ermöglichen. Dies könnte ein Grund sein, warum die entzündliche Reaktion bei Arthrose so schwach ausgeprägt ist.Inflammation in osteoarthritis is a secondary reaction to a degenerating process of the articular cartilage. Cause of Degeneration can be a disproportion of mechanical stress and resistance or metabolic diseases like diabetes mellitus. This kind of osteoarthritis is called "secondary osteoarthritis". Primary osteoarthritis has an unknown cause. Age and sex of the patient are a predictor for osteoarthritis, hense it is a disease of people above the age of 50 and more often it is found in women than in men. This paper investigated the synovial membranes of twenty patients to characterize the inflammatory Infiltrate. It characterized the cell surface antigen CD 20, CD 23, CD 40, CD 27, CD 3, CD 4, CD 8, Ki M4, CD 68, the antibodies IgG, IgA, IgM, Kappa, Lambda, the proliferating antigen Ki 67 and the expression profile of the cytokines IL 2 and IL 10 by using immunohistochemical staining (indirect immunoperoxidase technique and indirect immunofluorescence technique) with monoclonal antibodies. The synovial membrane shows in histology a dissemination of cover cells, fragments of cartilage and a slight expression of inflammatory infiltrate with a perivascular allocation. In only three of twenty cases we detected stronger inflammatory infiltrates. Most of the perivascular cells express CD 20. They are B lymphocytes. Plasma cells have more distance to the blood vessels and showed a predominant expression of IgG. T-lymphocytes were also detected perivascular. The expression of IL 10 was predominant. Lymphocytes aggregates like lymph follicle were detected in four of twenty cases. Macrophages were proved perivascular as well as in the cover cells. Ki M4 positive reticulum cells were found in only one of twenty cases. All kind of cells in the synovial membrane showed a low proliferation activity. The absence of germinal centers or comparable structures, the low expression of Ki M4 and Ki 67 speak against the immigration and maturation of native B lymphocytes in the synovial membrane. Memory B-lymphocytes don't need germinal centers or compatible structures for maturation, they can mature to plasma cells by help of T-lymphocytes, macrophages or other B-lymphocytes. It is more probably that the detected B lymphocytes are memory cells. The perivascular T lymphocytes in combination with the predominant expression of IL 10 may be interpreted as a TH2 immune reaction. This supports the maturation of B-lymphocytes to plasma cells. The maturation of memory B-lymphocytes under influence of TH2 immune reaction can be the reason for the missing of germinal centers or comparable structures. Matured B-lymphocytes don't need high-grade inflammatory cytokines for quick immune response. This is the possible reason for the low-grade inflammatory reaction of osteoarthritis.
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Scuderi, Richard. "G1-phase cyclin expression in neoplastic B cells /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-292-2/.
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Garrett, Joan Teresa. "Peptide-based B-cell epitope vaccines targeting HER-2/neu." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1189103626.
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Garrett, Joan T. "Peptide-based B-cell epitope vaccines targeting HER-2/neu." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1189103626.
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Thomenius, Michael James. "B-CELL LYMPHOMA-2 PROTEIN FAMILY, APOPTOSIS AND THE ENDOPLASMIC RETICULUM." Case Western Reserve University School of Graduate Studies / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=case1080679967.
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Zhang, Qiuheng, and 章秋桁. "The modulatory role of BCL-2 gene in the regulation of apoptosis inHL-60 cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31239754.
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Rodriguez, Rosie. "A study of the regulation of PLC 2 in B-cell signalling." Thesis, Institute of Cancer Research (University Of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404608.
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Merza, Mohammed. "Adherence to and invasion of mammalian cell lines by Pasteurella multocida B:2." Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/505/.
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Haemorrhagic septicemia (HS), caused by the Gram-negative bacterium Pasteurella multocida serotype B:2, is an economically important disease responsible for morbidity and mortality of bovines, especially buffaloes, in countries of South or Southeast Asia and Africa. A feature of this disease is the rapid spread of infecting bacteria from the respiratory tract to the blood and lymph to cause a fatal septicemia. To pass into the blood stream, the bacteria must migrate through the epithelial layer into the pulmonary interstitium. Avian serogroup A strains of P. multocida have been reported to invade cultured mammalian cells, but the behaviour of other of serogroups has not been reported. The main object of the work was to confirm that HS strains of P. multocida B:2 have the capacity to invade and survive within cultured mammalian cells, such as J774.2 cells (mouse macrophage-like cell lines) and BL-3 cells (bovine lymphoma cell line). Invasion, defined as adhesion to, followed by uptake by, or entry into, J774.2 macrophage cells or BL-3 cells was determined by: (I) counting of viable intracellular bacteria after killing extracellular bacteria with polymyxin and gentamicin, (II) Transmission electronic microscopy. Comparison of the invasiveness of a B:2 HS strain and its aroA derivative JRMT12 with that of P. multocida A:3 and E. coli XL1-Blue, showed that both P. multocida B:2 strains invaded both types of mammalian cells more readily than P. multocida A:3 and that E. coli XL1-Blue was essentially non-invasive. Both strains of P. multocida B:2 could survive within J774.2 macrophage and BL-3 cells for at least 2 h. A longer-term survival experiment (up to 6 h incubation) indicated that the numbers of intracellular bacteria declined between 4 to 6 h post-infection. It was shown by TEM that a significant proportion of the P. multocida B:2 bacteria were found within vacuoles in the cytoplasm of the mammalian cells with some free in the cytoplasm. A much reduced invasion capacity of P. multocida A:3 and E. coli XL1-Blue was detected. Different effects on the appearance and viability of J774.2 and BL-3 cells were observed by the trypan blue method and TEM when exposed to the P. multocida B:2 strains. Evaluation of cytotoxicity of P. multocida B:2 stains with J774.2 cells by the MTT assay produced unsatisfactory results.
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Cook, Sarah Louise. "The role of CC-chemokine receptor-like 2 in the B cell response." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5645/.
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CCRL2 is a member of the atypical chemattractant family. It has been proposed to bind the chemokines CCL19 and CCL5, as well as the adipokine chemerin. Unlike typical chemokine receptors, atypical chemoattractant receptors do not undergo conventional G protein signalling upon binding, but instead degrade, transcytose or present their ligands on the cell surface. This study aims to characterise the role of CCRL2 in B cells upon their activation and differentiation into either extrafollicular plasmablasts or germinal centre B cells. CCRL2 mRNA is upregulated upon plasmablast differentiation. Upon immunisation with NP-Ficoll, CCRL2 deficient mice produce more NP-specific antibody and larger numbers of NP-specific plasmablasts. Further assessment show this phenotype is due to B cell intrinsic effects. CCRL2 deficient plasmablasts tend to proliferate more and undergo less apoptosis than CCRL2 expressing plasmablasts. The role of CCRL2 in the germinal centre was also assessed. Germinal centres formed normally, including polarisation into light and dark zones in CCRL2 deficient mice. However, FDCs within the germinal centre appeared to extend further into the follicular mantle in CCRL2 deficient mice. This may be the cause of an increased proportion of germinal centres over the whole spleen in CCRL2 deficient mice. These differences did not result in significant changes in affinity maturation. Together, this shows a novel role for CCRL2 in the regulation of the extrafollicular plasmablast response to NP-Ficoll. However, minor differences in CCRL2 deficient germinal centres do not affect high affinity plasma cell output, suggesting a minimal role of CCRL2 in GC function.
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Sogwagwa, Nkosikho. "The role of Bcl-2 and bax protein expression on individual radiosensitivity." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2523.
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Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2017.Apoptosis is the dominant mechanism of cell death induced by radiation and is the key mechanism used to remove cells with significant DNA damage. Previous research investigated the feasibility of using the Leukocyte Apoptosis Assay (LAA) to determine individual sensitivity to radiation and it was found that an apoptotic response could be loosely linked to age, race and gender. Apoptosis is controlled by the Bcl-2 proteins and therefore the balance between Bax and Bcl-2 protein expression is important. With this background it would be relevant to know why certain individuals are more sensitive to radiation than others. The objectives of this study was to evaluate the effect of ionising radiation on apoptotic proteins, Bcl-2 (anti-apoptotic) and Bax (pro-apoptotic) expression and to explore if there is a relationship between radiation induced apoptosis (RIA) and Bcl-2 or Bax expression.
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Favre-Sahbi, Loëtitia. "Résistance à l’apoptose des cellules de lymphomes B infectées par le virus d’Epstein-Barr : rôle de l’autophagie et développement de nouveaux outils thérapeutiques." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS145.
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Notre équipe étudie les mécanismes de résistance à l’apoptose induite par divers agents dans les cellules de lymphomes B infectées ou non par le virus d’Epstein-Barr (EBV). EBV est un virus oncogénique de la famille des gamma-herpès virus qui est associé notamment au lymphome de Burkitt (LB) et aux syndromes lymphoprolifératifs post-transplantation (PTLD). Des résultats précédents ont montré que l’utilisation de la nutline-3, une molécule capable de se fixer sur MDM2, active p53 dans ces cellules tumorales. Cependant cette activation de p53 provoque l’apoptose des cellules B EBV(-) alors que les cellules B EBV(+) en latence III (exprimant toutes les protéines virales dites « de latence ») sont beaucoup plus résistantes. Mon travail de thèse a consisté à étudier les mécanismes impliqués dans cette résistance afin de mettre en place des stratégies thérapeutiques pour la contourner. La première partie de ma thèse a été consacrée à l’étude du rôle de l’autophagie dans la résistance des cellules EBV(+) en latence III à l’apoptose. L’autophagie est un processus de dégradation des protéines qui joue un rôle physiologique complexe impliqué à la fois dans la survie et dans la mort cellulaire. Les travaux effectués ont montré que: 1) l’autophagie est induite en réponse au traitement par la nutline dans les cellules EBV(+) en latence III ; 2) ces cellules expriment fortement la Bécline-1 et présentent une activation constitutive de l’autophagie ; 3) l’autophagie participe à la résistance de ces cellules à l’apoptose. La seconde partie de ma thèse a été consacrée au développement de nouvelles molécules ciblant les protéines anti-apoptotiques de la famille de Bcl-2. En effet, outre Bcl-2 qui est surexprimé dans les cellules EBV(+), les cellules de LB et les PTLD surexpriment aussi Mcl-1, une autre protéine anti-apoptotique. Or il a été montré que cette protéine était fréquemment à l’origine de résistance à des inhibiteurs déjà développés (et en essais cliniques) contre Bcl-2. Le développement de molécules ciblant Mcl-1 s’avère donc utile pour les contrer. Pour cela une collaboration avec une équipe de chimiste (dirigée par Fanny Roussi à l’Institut de Chimie des Substances Naturelles à Gif-sur-Yvette) a été mise en place. Nous avons identifié et étudié les mécanismes d’action de plusieurs molécules inhibitrices potentielles de Mcl-1 et/ou Bcl-xL capables d’induire l’apoptose dans nos deux modèles de lymphomesOur team investigates the mechanisms of resistance to apoptosis induced in various B-cell lymphomas including some infected by the Epstein-Barr virus (EBV). EBV is an oncogenic member in the gamma-herpesvirus family. Among other pathologies, it is associated with Burkitt’s lymphoma (BL) and post-transplant lymphoproliferative disorders (PTLD). Previously, our laboratory has found that in these tumor cells, the binding of nutlin-3 to MDM2 results in the activation of p53. However, although p53 activation leads to apoptosis in EBV(-) cells, EBV(+) latency III cells which express all viral « latency » proteins are much more resistant. During this PhD project, I studied the mechanisms involved in this resistance and made attempts to define new therapeutic strategies that would bypass them. First, the role played by autophagy was investigated. This catabolic process which degrades proteins and organelles is physiologically complex as it is involved in both cell survival and cell death. Our work has demonstrated that: 1) autophagy was induced in nutlin-3 treated EBV(+) latency III cells; 2) Beclin-1 was strongly expressed in these cells whose autophagy was constitutively activated; 3) autophagy was involved in the resistance to apoptosis observed in these cells. Second, I turned my efforts to the identification of new molecules targeting anti-apoptotic members of the Bcl-2 family. Like Bcl-2, the antiapoptotic protein Mcl-1 is heavily expressed in LB and PTLD cell lines but in this case, independently of their EBV status and this is a frequent cause for the observed resistance to Bcl-2 inhibitors that are currently tested in clinical trials. Molecules targeting Mcl-1 could thus prove promising to circumvent this resistance. In a collaboration with a Chemistry team supervised by Fanny Roussi at the Institut de Chimie des Substances Naturelles in Gif-sur-Yvette, we have identified the mechanisms of action of potential inhibitors of Mcl-1 and/or Bcl-xL, another anti-apoptotic molecules which induce apoptosis in our two lymphoma models
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Palerme, Jean-Sebastien. "Factors influencing the murine B and T cell response to human 2-glycoprotein I." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33818.
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Antiphospholipid syndrome (APS) is defined by the presence of antiphospholipid antibodies (aPL) and clinical manifestations. It is unclear why some patients have high levels of aPL, but no clinical symptoms, while others develop APS. Recent studies have demonstrated T cell reactivity to beta2-glycoprotein I (beta2GPI) in patients with APS. To understand why a T cell response develops selectively in some individuals the requirements for antigen presentation and T cell reactivity were evaluated in a murine model of aPL induction. aPL were readily induced in immunized mice, and required MHC class II, but not CD1, antigen presentation. In contrast, induction of a measurable T cell response to beta2GPI necessitated hyperimmunization in the presence of a polyclonal activator. T cells reacted more to reduced, than native, beta2GPI, suggesting that disulfide bond reduction facilitates antigen processing. These results suggest that a T cell response to beta2GPI occurs only in individuals repeatedly exposed to antigen in a proinflammatory environment.
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Dakappagari, Naveen K. "Evaluation of chimeric B-cell epitope vaccines of HER-2 : application to cancer patients /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu148639784122275.
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Knights, Kaori. "The role of hypoxia and complement receptor 2 or toll-like receptor 2 on B1 B cell effector function." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/15852.
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Master of ScienceDivision of Biology
Sherry D. Fleming
Professional phagocytes play a critical role in maintaining homeostasis within a host through phagocytic, microbicidal, and inflammatory activity. Complement receptors (CR) and toll-like receptors (TLRs) aid in phagocytosis and stimulate these cells to enhance the immune response. Environmental factors such as hypoxia, prevalent at sites of tissue damage or infection, induce a similar effect. Systemic components such as opsonins may further enhance phagocyte activity. Similar to professional phagocytes, B1 B cells exhibit a broad range of immunological activity as well as expression of CRs and TLRs. Despite extensive studies with other phagocytes, the effects of CRs and TLRs expression, hypoxic stimulation, or opsonization on B1 B cell function remain unclear. We tested the hypothesis that TLR2 stimulation, hypoxia, CR2 expression, or opsonins would enhance B1 B cell phagocytic and inflammatory activity. Negatively selected peritoneal cavity B1 B cells from the (PerC) of wild type, Tlr2[superscript]-[superscript]/[superscript]-, and Cr2[superscript]-[superscript]/[superscript]- mice, or a B1 B-like cell line, Wehi 231, were subjected to normoxia or hypoxia with or without particles for phagocytosis, TLR2 agonists, or CR2 ligands. The PerC of Tlr2[superscript]-[superscript]/[superscript]- mice contained an altered B1 B cell subset distribution while Cr2[superscript]-[superscript]/[superscript]- mice exhibited a normal repertoire. We demonstrated that hypoxia significantly downregulated inflammatory cytokine production by B1 B cells, while upregulating phagocytic activity in a TLR2 or CR2 dependent manner. TLR2 or CR2 deficiency altered constitutive production of B1 B cell associated cytokines. The CR2 ligand C3d, an opsonin, significantly enhanced the phagocytic activity of B1 B cells but failed to stimulate cytokine production. However, Cr2[superscript]-[superscript]/[superscript]- B1 B cells phagocytosed C3d-coated particles suggesting multiple CR may play a role in B1 B cell phagocytosis. Overall, the data suggest TLRs, CRs, hypoxia, and opsonization all contribute to B1 B cell effector function similar to professional phagocytes.