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1
Lin, Tzu-yin. "The world according to mast cells the role of Kit in normal and neoplastic canine mast cells /." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1189098916.
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Bennett, Haley Lorraine Garvan Institute of Medical Research Faculty of Medicine UNSW. "Co-operation between the docking protein GAB2 and the protein tyrosine kinase src in human mammary epithelial cells." Awarded by:University of New South Wales, 2008. http://handle.unsw.edu.au/1959.4/39486.
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The Gab2 docking protein is a target of several oncogenic protein tyrosine kinases and potentiates activation of the Ras/extracellular signal regulated kinase and phosphatidylinositol 3-kinase (PI3-kinase) pathways. The prototypical member of the Src family of protein tyrosine kinases, c-Src, phosphorylates Gab2 and both proteins are overexpressed in breast cancers. However, whether overexpression of these two proteins contributes to mammary tumourigenesis had not been previously investigated. Pharmacological inhibition of c-Src in breast cancer cell lines reduced Gab2 tyrosine phosphorylation while overexpression of these two proteins increased this effect, demonstrating a contribution of c-Src to Gab2 tyrosine phosphorylation in breast cancer cells. The biological effects of Gab2 and c-Src overexpression were determined in a three-dimensional cell culture model using the human mammary epithelial cell line MCF-10A. When cultured on a basement membrane, MCF10A cells form acini that model mammary lobules in vivo. Overexpression of Gab2 in MCF10As conferred increased acinar size and independence of the morphogenetic program from exogenous EGF. While overexpression of c-Src alone did not affect acinar morphogenesis, it potentiated the EGF-independent acinar growth induced by Gab2 overexpression. As enhanced c-Src kinase activity is often observed in breast cancer, the effect of Gab2 co-expression with active Src constructs was next determined. Expression of v-Src or c-SrcY527F altered acinar morphology and the resulting structures were categorised as spheroidal, discohesive or dispersed, according to the degree of phenotypic disruption. Gab2 co-expression shifted the proportion of structures towards the dispersed phenotype. This shift reflects a negative role for Gab2 at adherens junctions in the context of active Src expression, as in monolayer cells Gab2 significantly decreased E-cadherin-based adhesive strength without altering the surface expression of this adhesion molecule. Furthermore, Gab2 associated with the E-cadherin complex. The ability of Gab2 to weaken the strength of cell-cell contacts in active Src-expressing cells may be due to enhanced activation of PI3-kinase signalling at adherens junctions, as the potentiating effects of Gab2 in both monolayer and three-dimensional cultures were dependent upon Gab2 recruitment of the p85 subunit of PI3-kinase. Finally, Gab2 increased migration and invasion of v-Src-expressing cells in transwell assays, however these effects were p85-independent. This is the first study to demonstrate Gab2 co-operation with various forms of Src to augment proliferative, invasive and migratory signals, as well as revealing a novel mechanism whereby Gab2 may promote metastatic spread. This study thus demonstrates multiple roles for Gab2 in contributing to breast cancer progression.
3
Zhang, Deyong, and 張德勇. "The regulation of cardiac potassium channels by protein tyrosine kinases." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41508294.
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Zhang, Deyong. "The regulation of cardiac potassium channels by protein tyrosine kinases." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41508294.
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Ekman, Niklas. "The Bmx tyrosine kinase : a signal mediator in hematopoietic and endothelial/epithelial cells." Helsinki : University of Helsinki, 2003. http://ethesis.helsinki.fi/julkaisut/mat/bioti/vk/ekman/.
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Jiang, Liying. "Exposure of endothelial cells to shear stress stimulates protein tryosine phosphorylation." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/25421.
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Edling, Charlotte. "Receptor tyrosine kinase c-Kit signalling in hematopoietic progenitor cells." Doctoral thesis, Umeå : Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-888.
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Gavériaux, Claire. "Etude de l'interaction entre l'immunoglobuline e et son recepteur de forte affinite : mise au point d'un nouvel essai immunoenzymatique sur cellules, le celisa, importance de la n-glycosylation et de l'activation de la proteine kinase c dans l'expresion fonctionnelle de ce recepteur." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13014.
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Heinonen, Juhana E. "Molecular dissection of Bruton's tyrosine kinase signaling in hematopoietic cells using RNAi /." Stockholm : Karolinska institutet, 2007. http://diss.kib.ki.se/2007/978-91-7357-320-7/.
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Kerner, James David. "The significance of Bruton tyrosine kinase in multiple stages of B lymphopoiesis /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/8347.
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Annerén, Cecilia. "The Tyrosine Kinase GTK : Signal Transduction and Biological Function." Doctoral thesis, Uppsala University, Department of Medical Cell Biology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1384.
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Protein tyrosine kinases play an important role in the regulation of various cellular processes such as
growth, differentiation and survival. GTK, a novel SRC-like cytoplasmic tyrosine kinase, was recently cloned from a mouse insulinoma cell line and the present work was conducted in order to find a biological function of GTK in insulin producing and neuronal cells. It was observed that kinase active GTK-mutants, expressed in RINm5F cells, transferred to the cell nucleus and increased the levels of the cell cycle regulatory protein p27KIP1, reduced cell growth and stimulated glucagon mRNA expression. Furthermore, wild type GTK induces neurite outgrowth in the rat adrenal pheochromocytoma PC12 cell line, through activation of the RAP1-pathway, suggesting a role of GTK for cell differentiation. Studies using transgenic mice, expressing GTK under the control of the rat insulin 1 promoter, demonstrated a dual role of GTK for β-cell growth: Whereas GTK increases the β-cell mass and causes enhanced β-cell proliferation in response to partial pancreatectomy it also induced β-cell death in response to proinflammatory cytokines and impaired the glucose tolerance in mice treated with the β-cell toxin streptozotocin suggesting a possible role of GTK for β-cell destruction in Type 1 diabetes. We have also observed that GTK-transgenic islets and GTK-expressing RINm5F cells exhibit a reduced insulininduced activation of the insulin receptor substrate (IRS-1 and IRS-2)-pathways, partly due to an increased basal activity of these. GTK was found to associate with and phosphorylate the SH2 domain adapter protein SHB, which could explain many of the GTK-dependent effects both in vitro and in vivo. In summary, the present work suggests that the novel tyrosine kinase GTK is involved in various signal transduction pathways, regulating different cellular responses, such as proliferation, differentiation and survival.
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Knights, Victoria E. E. "Tumour cell responses to novel fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608393.
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Xu, Yuekang. "Biochemical basis of B cell dysfunction in lyn kinase deficient mice /." Connect to thesis, 2003. http://eprints.unimelb.edu.au/archive/00002881.
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Thesis (Ph.D.)--University of Melbourne, The Walter & Eliza Hall Institute of Medical research, Dept. of Medical Biology, 2004.Typescript (photocopy). Includes bibliographical references (leaves 161-190).
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Hirai, Kennzo. "Protein-tyrosine-kinase-dependent expression of cyclo-oxygenase-1 and -2m RNAs in human endothelial cells." Kyoto University, 1999. http://hdl.handle.net/2433/181753.
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Geng, Wei. "The role of proline rich tyrosine kinase 2 (Pyk2) on cisplatin resistance in HCC." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43224106.
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Yamasaki, Masahide. "Monocyte chemoattractant protein-1 causes differential proline-rich tyrosine kinase 2-mediated signaling in THP-1 cells." Kyoto University, 2001. http://hdl.handle.net/2433/150583.
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Geng, Wei, and 耿瑋. "The role of proline rich tyrosine kinase 2 (Pyk2) on cisplatin resistance in HCC." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43224106.
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Lavens-Phillips, Sandra Elizabeth. "The role of tyrosine kinases in signal transduction mechanisms utilised by human lung mast cells and basophils." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243050.
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Conway, Ann Marie. "Growth factor receptor tyrosine kinase-, G-protein coupled receptor- and sphingolipid-dependent regulation of the extracellular signal-regulated kinase cascade in cultured airway smooth muscle cells." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366970.
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Drube, Julia [Verfasser], Frank-D. [Gutachter] Böhmer, Christian [Gutachter] Kosan, and Wilhelmus J. [Gutachter] Hendriks. "The role of protein-tyrosine phosphatases for sensitivity and resistance of CML-cells to tyrosine-kinase inhibitors / Julia Drube ; Gutachter: Frank-D. Böhmer, Christian Kosan, Wilhelmus J. Hendriks." Jena : Friedrich-Schiller-Universität Jena, 2018. http://d-nb.info/1170587267/34.
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Macêdo, Thais Rodrigues. "Comparação da eficácia do mesilato de imatinibe com a vimblastina associada a prednisona no tratamento do mastocitoma canino: estudo clínico, histopatológico, imunohistoquímico e molecular." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/10/10137/tde-05012015-094225/.
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O objetivo deste trabalho foi avaliar a eficácia do mesilato de imatinibe, em comparação com a quimioterapia usual com vimblastina e prednisona, no tratamento do mastocitoma canino e descrever os efeitos colaterais apresentados pelas medicações. Bem como analisar a expressão do VEGF (fator de crescimento endotelial), a relação da expressão do gene c-kit por RT-PCR e marcação imunoistoquímica do KIT com a presença de mutações na justamembrana e a relação desta mutação com a resposta à terapia. Para tanto foram incluídos 29 animais com diagnóstico citológico de mastocitoma, estes animais foram submetidos a tomografia computadorizada para determinação das medidas das formações cutâneas e em seguida divididos em 2 grupos. O grupo 1 foi tratado com o protocolo quimioterápico de vimblastina e prednisona por 12 semanas e o grupo 2 com o mesilato de imatinibe na dose de 10 mg/Kg a cada 24 horas por 8 semanas. A avaliação da resposta ao tratamento foi realizada com mensurações periódicas das formações com paquímetro e nova tomografia ao final do tratamento para mensuração do maior diâmetro e volume tumoral. Um fragmento das formações cutâneas foi coletado antes do início do tratamento para graduação histológica da neoplasia, determinação do índice mitótico e imunomarcação para KIT, VEGF e Ki- 67. Parte do material coletado teve o DNA e RNA extraídos e posterior sequenciamento dos exons 11 do gene c-kit e determinação da expressão deste e do seu ligante por RT-PCR. A toxicidade a medicação foi avaliada segundo as normas do VCOG 1.1.A taxa de resposta do grupo VP foi de 7,7 % e no grupo MI de 28,6%, embora os pacientes tratados com mesilato de imatinibe tenham apresentado maior chance de resposta a terapia, não foi observado diferença entre os dois grupos. Os dois protocolos foram bem tolerados, os pacientes do grupo MI d menor número de efeitos colaterais. O grau histológico, Indice mitótico, padrão imunohistoquimico do KIT, além da quantificação do ki-67 foram homogêneos nos dois grupos e não influenciaram na resposta ao tratamento. A quantificação do VEGF foi mais intensa nos pacientes com remissão parcial e total. Não foi observado relação entre a quantificação do KIT e a expressão do gene c-kit, que foi maior nos pacientes que responderam ao tratamento, porém a associação desta com a resposta a terapia não pode ser determinada. Mutações ativantes no exon11 do gene c-kit não foram identificadas. O tratamento com o mesilato de imatinibe é bem tolerado pelos animais, no entanto este não se mostrou superior ao protocolo padrão de quimioterapia para o tratamento do mastocitoma; este resultado pode ter sido influenciado pelo número de animais incluídos no estudo. Mutações em outros domínios do receptor KIT e a ação do ITK em receptores como do PDGF e o VEGF podem estar relacionados a resposta a esta classe de fármacos observada neste estudo, a despeito da ausência de mutações ativantes no exon 11 do gene c-kit.The objective of this study was to evaluate the efficacy of imatinib mesylate, compared with the usual chemotherapy with vinblastine and prednisone in the treatment of canine mast cell tumor and describe the side effects submitted by medications. Well as analyzing the expression of VEGF (vascular endothelial growth factor), the relationship between the expression of c-kit gene by RT-PCR and immunohistochemical staining of KIT with the presence of mutations in the juxtamembrane and the relationship of this mutation with response to therapy. For both 29 animals with cytological diagnosis of mast cell tumor were included, these animals underwent computed tomography to determine the measured skin formations and then divided into 2 groups. Group 1 was treated with the chemotherapeutic protocol vinblastine and prednisone for 12 weeks and the second group with the imatinib mesylate in a dose of 10 mg / kg every 24 hours for 8 weeks. The assessment of response to treatment was performed with periodic measurements of the formations Caliper and a new computed tomography in the end of treatment to measure the largest tumor diameter and volume. A fragment of skin formations was collected before the initiation of treatment for histological grading, determination of mitotic index, KIT and VEGF staining patterns and the proliferation marker Ki67. Part of the collected material was extracted RNA and DNA and subsequent sequencing of 11 exons of the c-kit gene and determination and expression of its ligand by RT-PCR. The medication toxicity was evaluated according to the standards of VCOG 1.1.A response rate of the VP group was 7.7% and 28.6% MI group, although patients treated with imatinib had a higher chance of response therapy, no difference in response between the two groups was observed. The two protocols were well tolerated, patients in the MI group had a smaller number of side effects. The histological grade, mitotic index, staining patterns KIT, beyond the quantification of Ki-67 were homogeneous in both groups and did not influence the response to treatment. Quantification of VEGF was intensely in patients with partial and total remission. It was no relationship between KIT and quantification of the expression of c-kit gene, which was higher in patients who responded to treatment, but its association with response to therapy cant be determined. Exon11 activating mutations in the c-kit gene were not identified. Treatment with imatinib mesylate is well tolerated by the animals, however this was not superior to standard chemotherapy protocol for the treatment of mast cell tumors; this result may have been influenced by the number of animals included in the study. Mutations in other domains of the KIT receptor and action in ITK receptors as PDGF and VEGF may be related to response to this class of drugs in this study, despite the absence of activating mutations in exon 11 of c-kit gene.
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Christiansson, Lisa. "Myeloid-Derived Suppressor Cells and Other Immune Escape Mechanisms in Chronic Leukemia." Doctoral thesis, Uppsala universitet, Klinisk immunologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-197604.
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Chronic myeloid leukemia (CML) is characterized by the Philadelphia chromosome, a minute chromosome that leads to the creation of the fusion gene BCR/ABL and the transcription of the fusion protein BCR/ABL in transformed cells. The constitutively active tyrosine kinase BCR/ABL confers enhanced proliferation and survival on leukemic cells. CML has in only a few decades gone from being a disease with very bad prognosis to being a disease that can be effectively treated with oral tyrosine kinase inhibitors (TKIs). TKIs are drugs inhibiting BCR/ABL as well as other tyrosine kinases. In this thesis, the focus has been on the immune system of CML patients, on immune escape mechanisms present in untreated patients and on how these are affected by TKI therapy. We have found that newly diagnosed, untreated CML patients exert different kinds of immune escape mechanisms. Patients belonging to the Sokal high-risk group had higher levels of myeloid-derived suppressor cells (MDSCs) as well as high levels of the programmed death receptor 1 (PD-1)-expressing cytotoxic T cells compared to control subjects. Moreover, CML patients had higher levels of myeloid cells expressing the ligand for PD-1, PD-L1. CML patients as well as patients with B cell malignacies had high levels of soluble CD25 in blood plasma. In B cell malignacies, sCD25 was found to be released from T regulatory cells (Tregs). Treatment with the TKIs imatinib or dasatinib decreased the levels of MDSCs in peripheral blood. Tregs on the other hand increased during TKI therapy. The immunostimulatory molecule CD40 as well as NK cells increased during therapy, indicating an immunostimulatory effect of TKIs. When evaluating immune responses, multiplex techniques for quantification of proteins such as cytokines and chemokines are becoming increasingly popular. With these techniques a lot of information can be gained from a small sample volume and complex networks can be more easily studied than when using for example the singleplex ELISA. When comparing different multiplex platforms we found that the absolute protein concentration measured by one platform rarely correlated with the absolute concentration measured by another platform. However, relative quantification was better correlated.
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Condon, Peter J. "Novel, Functional Interactions Between TrkA Kinase and p75 Neurotrophin Receptor in Neuroblastoma Cells: A Dissertation." eScholarship@UMMS, 2003. http://escholarship.umassmed.edu/gsbs_diss/148.
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To understand the functional interactions between the TrkA and p75 nerve growth factor (NGF) receptors, we employed several lines of investigation including biophysical, biochemical and cellular assays. A high-affinity nerve growth factor (NGF) receptor is thought to be a complex of two receptors, p75 and the receptor tyrosine kinase, TrkA. The existence of a gp75-TrkA complex was demonstrated by a copatching technique. p75 on the surface of intact cells is patched with an anti-p75 antibody and fluorescent secondary antibody, the cells are then fixed to prevent further antibody-induced redistributions, and the distribution of TrkA is probed with an anti-TrkA antibody and fluorescent secondary antibody. We utilize a baculovirus-insect cell expression system, which allows high level expression of wild-type and mutated NGF receptors. TrkA and p75 copatch in both the absence and presence of NGF. This association is specific, since p75 does not copatch with other tyrosine kinase receptors, including TrkB, platelet-derived growth factor receptor-β and Torso (Tor). To determine which domains of TrkA are required for copatching, we used a series of TrkA-Tor chimeric receptors and show that the extracellular domain of TrkA is sufficient for copatching with p75. A chimeric receptor with TrkA transmembrane and intracellular domains shows partial copatching with p75. Deletion of the intracellular domain of p75 decreases but does not eliminate copatching. A point mutation that inactivates the TrkA kinase has no effect on copatching, indicating that this enzymatic activity is not required for association with p75. Hence, although interactions between the p75 and TrkA extracellular domains are sufficient for complex formation, interactions involving other receptor domains also play a role.
To study what signal transduction mechanisms were activated by the two receptors to bring about differentiation and survival, we stably transfected LAN5 neuroblastoma cells with an expression vector for ET-R, a chimeric receptor with the extracellular domain of the epidermal growth factor receptor (EGFR) and the TrkA transmembrane and intracellular domains. EGF activated the ET-R kinase and induced partial differentiation. NGF, which can bind to endogenous p75, did not induce differentiation, but enhanced the EGF-induced response, leading to differentiation of almost all of the cells. A mutated NGF, 3T-NGF, that binds to TrkA but not to p75 did not synergize with EGF. Enhancement of EGF-induced differentiation required at least nanomolar concentrations of NGF, consistent with the low-affinity p75 binding site. EGF may induce a limited number of neuronal cells because it also enhances apoptosis. Both NGF and a caspase inhibitor reduced apoptosis and, thereby, enhanced differentiation. NGF appears to enhance survival through the phosphatidylinositol-3 kinase (PI3K) pathway. Consistent with this hypothesis, Akt, a downstream effector of the PI3K pathway, was hyperphosphorylated in the presence of EGF+NGF. These results demonstrate that TrkA kinase initiates differentiation, and p75 enhances differentiation by rescuing differentiating cells from apoptosis via the PI3K pathway.
Even though both EGF and NGF are required for differentiation of LAN5/ET-R cells, only NGF is required for survival of the differentiated cells. In the absence of NGF, the cells die by an apoptotic mechanism, involving caspase-3. An anti-p75 antibody blocked the survival effect of NGF. Brain-derived neurotrophic factor also enhanced cell survival, indicating that in differentiated cells, NGF acts through the p75 receptor to prevent apoptosis.
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Miller, Andrew Todd. "The Function of the Tyrosine Kinase, Itk, in CD4+ T Cell Differentiation and Death: a Dissertation." eScholarship@UMMS, 2003. https://escholarship.umassmed.edu/gsbs_diss/58.
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The Tec family tyrosine kinase, Itk, plays an important role in signal transduction following T cell receptor engagement. Several prior studies have established the importance of Itk in immune system processes, such as T cell development and T cell activation. Additional biochemical studies have found that Itk specifically functions within a multi-molecular signalosome complex, which ultimately functions to provide a platform by which Itk can phosphorylate and activate PLC-γ1, a crucial step in T cell activation. To further study how Itk regulates distinct immune outcomes via T cell effector processes within the peripheral immune system, and to further understand how Itk functions in T cells in response to a physiological ligand-receptor interaction, I crossed Itk-deficient mice to mice transgenic for a TCR specific for a moth cytochrome C peptide. My studies have established a unique role for Itk in several important aspects of T cell function. Following T cell activation, I identified an imperative role for Itk in activation-induced cell death via FasL, a mechanism of immune homeostasis. Furthermore, I found Itk plays a unique role in the process of T cell differentiation, where Itk positively regulates the induction of cytokine genes, such as IL-4, while negatively regulating the induction of T-bet, a transcription factor important for Th1 differentiation. Lastly, following T cell differentiation, I found that Itk mRNA and protein are up-regulated during Th2 differentiation, while Rlk, a related Tec kinase, disappears rapidly from Th2 cells, indicating a critical role for Itk in Th2 cell function. Collectively, my thesis work has more clearly defined an important function for Itk not only in TCR signaling, but also in immune processes such as T cell differentiation and activation-induced cell death that are required for proper immune function.
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Prince, Amanda L. "The Role of Inducible T Cell Kinase (Itk) in the Development of Innate T Cells and in the Formation of Protective Memory Responses: A Dissertation." eScholarship@UMMS, 2002. http://escholarship.umassmed.edu/gsbs_diss/660.
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T cell development in the thymus produces multiple lineages of cells, including conventional naïve CD4+ and CD8+ T cells, regulatory T cells, and innate T cells. Innate T cells encompass γδ T cells, invariant natural killer (iNKT) cells, mucosal-associated invariant T (MAIT) cells, and H2-M3-restricted cells (Berg, 2007). Although they are a minor subset of all thymocytes, innate T cells develop in the thymus and share characteristics of the innate and adaptive immune systems (Berg, 2007). These lymphocytes undergo antigen receptor rearrangement and are able to exert their effector function immediately upon ex vivo stimulation (Berg, 2007). However, in several strains of mice harboring mutations in T cell signaling proteins or transcriptional regulators, conventional CD8+ T cells develop as innate cells that share characteristics with memory T cells (Atherly et al., 2006b; Broussard et al., 2006; Fukuyama et al., 2009; Gordon et al., 2011; Verykokakis et al., 2010b; Weinreich et al., 2010). One of these signaling proteins, inducible T cell kinase (Itk) is a nonreceptor protein tyrosine kinase that signals downstream of the T cell receptor (TCR) (Berg et al., 2005). Upon TCR activation, Itk is activated and recruited to the TCR signaling complex, where Itk interacts with Src homology 2 (SH2) domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76), linker for activation of T cells (LAT), and phospholipase C γ1 (PLCγ1) (Berg et al., 2005). Thus, in Itk-deficient mice, TCR signaling is disrupted, which results in mature CD4- CD8+ (CD8SP) thymocytes that are CD44high, CD62Lhigh, CD122+, and CXCR3+ and that express high levels of the transcription factor, Eomesodermin (Eomes) (Atherly et al., 2006b; Broussard et al., 2006; Weinreich et al., 2010). Recently, it was determined that the development of these innate CD8SP thymocytes in itk-/- mice is dependent on IL-4 produced in the thymic environment by a poorly characterized subset of CD3+ thymocytes expressing the transcriptional regulator, promyelocytic leukemia zinc finger (PLZF) (Gordon et al., 2011; Verykokakis et al., 2010b; Weinreich et al., 2010). Here we show that a sizeable proportion of mature CD4+ CD8- (CD4SP) thymocytes in itk-/- mice also develop as Eomesodermin+ innate T cells. These Eomes+ innate CD4+ T cells are CD44high, CD62Lhigh, CD122+, and CXCR3+ (Atherly et al., 2006b; Broussard et al., 2006; Dubois et al., 2006; Weinreich et al., 2010). Surprisingly, neither CD4SP nor CD8SP innate thymocytes in itk-/- mice are dependent on γδ T cells for their development as was previously hypothesized (Alonzo and Sant'Angelo, 2011). Instead, both subsets of innate itk-/- T cells require the presence of a novel PLZF-expressing, SAP-dependent thymocyte population that is essential for the conversion of conventional CD4+ and CD8+ T cells into Eomesodermin-expressing innate T cells with a memory phenotype. This novel subset of PLZF-expressing SAP-dependent innate T cells preferentially home to the spleen and mesenteric lymph nodes and have a restricted TCR repertoire. Thus, we have christened this subset as CD4+ PLZF + MAIT-like cells. We have characterized multiple subsets of innate T cells that expand in the absence of Itk. Therefore, we were interested in how innate T cells respond to infection. Although Itk KO mice have defects in cytolytic function and cytokine production during an acute infection, these mice are able to clear viral infections (Atherly et al., 2006a; Bachmann et al., 1997). Hence, we hypothesized that Itk-deficient memory CD8+ T cells would be able to provide protection upon a challenge infection. Conversely, we found this not to be true although Itk-deficient memory CD8+ T cells were present in similar frequencies and cell numbers as WT memory CD8+ T cells at 42 days post-infection. Furthermore, Itk-deficient memory CD8+ T cells were able to produce IFNγ and exert cytolytic function upon stimulation. Although the function of Itk-deficient memory CD8+ T cells appeared to be intact, we found that these cells were unable to expand in response to a challenge infection. Remarkably, conventional memory CD8+ T cells lacking Itk were able to expand and form protective memory responses upon challenge. Thus, the inability of Eomes+ innate CD8+ T cells to form protective memory responses does not appear to be intrinsic to cells deficient in Itk. This thesis is divided into six major chapters. The first chapter will provide an introduction to T cell development and the role of Itk in T cell development. Additionally, it will introduce a variety of innate T cell subsets that will be discussed throughout this thesis and will provide an overview of CD4+ and CD8 + T cell differentiation during infection. This section will explain the role of Itk in CD4+ helper T cell differentiation and describe how Itk-deficient CD8+ T cells respond to acute infection. The introduction will also discuss the generation of conventional memory CD8+ T cells. The second chapter will provide the details of the experimental procedures used in this thesis. The third chapter will describe the characterization and development of Eomes+ innate CD4+ T cells that develop in the absence of Itk. Additionally, this chapter will address the subset of PLZF+ innate T cells that induce the expression of Eomes in innate T cells. The fourth chapter will further characterize and explore the development of itk-/- CD4+ PLZF+ MAIT-like T cells. The fifth chapter will examine the role of Eomes + innate CD8+ T cells in protective memory responses. Chapters three through five will display work that is in preparation to be submitted to a peer-reviewed journal. The sixth chapter will discuss the results of this thesis and their implications.
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Prince, Amanda L. "The Role of Inducible T Cell Kinase (Itk) in the Development of Innate T Cells and in the Formation of Protective Memory Responses: A Dissertation." eScholarship@UMMS, 2013. https://escholarship.umassmed.edu/gsbs_diss/660.
Full textAbstract:
T cell development in the thymus produces multiple lineages of cells, including conventional naïve CD4+ and CD8+ T cells, regulatory T cells, and innate T cells. Innate T cells encompass γδ T cells, invariant natural killer (iNKT) cells, mucosal-associated invariant T (MAIT) cells, and H2-M3-restricted cells (Berg, 2007). Although they are a minor subset of all thymocytes, innate T cells develop in the thymus and share characteristics of the innate and adaptive immune systems (Berg, 2007). These lymphocytes undergo antigen receptor rearrangement and are able to exert their effector function immediately upon ex vivo stimulation (Berg, 2007). However, in several strains of mice harboring mutations in T cell signaling proteins or transcriptional regulators, conventional CD8+ T cells develop as innate cells that share characteristics with memory T cells (Atherly et al., 2006b; Broussard et al., 2006; Fukuyama et al., 2009; Gordon et al., 2011; Verykokakis et al., 2010b; Weinreich et al., 2010). One of these signaling proteins, inducible T cell kinase (Itk) is a nonreceptor protein tyrosine kinase that signals downstream of the T cell receptor (TCR) (Berg et al., 2005). Upon TCR activation, Itk is activated and recruited to the TCR signaling complex, where Itk interacts with Src homology 2 (SH2) domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76), linker for activation of T cells (LAT), and phospholipase C γ1 (PLCγ1) (Berg et al., 2005). Thus, in Itk-deficient mice, TCR signaling is disrupted, which results in mature CD4- CD8+ (CD8SP) thymocytes that are CD44high, CD62Lhigh, CD122+, and CXCR3+ and that express high levels of the transcription factor, Eomesodermin (Eomes) (Atherly et al., 2006b; Broussard et al., 2006; Weinreich et al., 2010). Recently, it was determined that the development of these innate CD8SP thymocytes in itk-/- mice is dependent on IL-4 produced in the thymic environment by a poorly characterized subset of CD3+ thymocytes expressing the transcriptional regulator, promyelocytic leukemia zinc finger (PLZF) (Gordon et al., 2011; Verykokakis et al., 2010b; Weinreich et al., 2010). Here we show that a sizeable proportion of mature CD4+ CD8- (CD4SP) thymocytes in itk-/- mice also develop as Eomesodermin+ innate T cells. These Eomes+ innate CD4+ T cells are CD44high, CD62Lhigh, CD122+, and CXCR3+ (Atherly et al., 2006b; Broussard et al., 2006; Dubois et al., 2006; Weinreich et al., 2010). Surprisingly, neither CD4SP nor CD8SP innate thymocytes in itk-/- mice are dependent on γδ T cells for their development as was previously hypothesized (Alonzo and Sant'Angelo, 2011). Instead, both subsets of innate itk-/- T cells require the presence of a novel PLZF-expressing, SAP-dependent thymocyte population that is essential for the conversion of conventional CD4+ and CD8+ T cells into Eomesodermin-expressing innate T cells with a memory phenotype. This novel subset of PLZF-expressing SAP-dependent innate T cells preferentially home to the spleen and mesenteric lymph nodes and have a restricted TCR repertoire. Thus, we have christened this subset as CD4+ PLZF + MAIT-like cells. We have characterized multiple subsets of innate T cells that expand in the absence of Itk. Therefore, we were interested in how innate T cells respond to infection. Although Itk KO mice have defects in cytolytic function and cytokine production during an acute infection, these mice are able to clear viral infections (Atherly et al., 2006a; Bachmann et al., 1997). Hence, we hypothesized that Itk-deficient memory CD8+ T cells would be able to provide protection upon a challenge infection. Conversely, we found this not to be true although Itk-deficient memory CD8+ T cells were present in similar frequencies and cell numbers as WT memory CD8+ T cells at 42 days post-infection. Furthermore, Itk-deficient memory CD8+ T cells were able to produce IFNγ and exert cytolytic function upon stimulation. Although the function of Itk-deficient memory CD8+ T cells appeared to be intact, we found that these cells were unable to expand in response to a challenge infection. Remarkably, conventional memory CD8+ T cells lacking Itk were able to expand and form protective memory responses upon challenge. Thus, the inability of Eomes+ innate CD8+ T cells to form protective memory responses does not appear to be intrinsic to cells deficient in Itk. This thesis is divided into six major chapters. The first chapter will provide an introduction to T cell development and the role of Itk in T cell development. Additionally, it will introduce a variety of innate T cell subsets that will be discussed throughout this thesis and will provide an overview of CD4+ and CD8 + T cell differentiation during infection. This section will explain the role of Itk in CD4+ helper T cell differentiation and describe how Itk-deficient CD8+ T cells respond to acute infection. The introduction will also discuss the generation of conventional memory CD8+ T cells. The second chapter will provide the details of the experimental procedures used in this thesis. The third chapter will describe the characterization and development of Eomes+ innate CD4+ T cells that develop in the absence of Itk. Additionally, this chapter will address the subset of PLZF+ innate T cells that induce the expression of Eomes in innate T cells. The fourth chapter will further characterize and explore the development of itk-/- CD4+ PLZF+ MAIT-like T cells. The fifth chapter will examine the role of Eomes + innate CD8+ T cells in protective memory responses. Chapters three through five will display work that is in preparation to be submitted to a peer-reviewed journal. The sixth chapter will discuss the results of this thesis and their implications.
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Abbott, Mary-Alice. "Structural and Signaling Proteins at the Synapse: Dystroglycan & Insulin Receptor Tyrosine Kinase Substrate p58/53: a Dissertation." eScholarship@UMMS, 1999. https://escholarship.umassmed.edu/gsbs_diss/124.
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The synapse is the primary locus of cell-cell communication in the nervous system. The elaboration of a functional synapse requires both a specialized structure and an efficient communication system. For my thesis work, I studied proteins implicated in each of these functions: the structural molecules dystroglycan and dystrophin, and the signaling elements Insulin Receptor Substrate p58/53 and insulin receptor.
The α/β-dystroglycan complex, believed to be the heart of cellmatrix adhesion in muscle and other tissues, provides a link between dystrophin, a cytoskeletal protein at the base of the muscle cell's Dystrophin Associated Protein Complex, and the extracellular matrix. In addition, dystrophin is found at central synapses, tightly associated with the postsynaptic density. The absence of dystrophin and the secondary loss of its associated proteins causes the genetic disease Duchenne Muscular Dystrophy. DMD affects both muscle and brain, causing a severe muscular dystrophy and lower IQs than control groups.
In the first portion of my thesis work, I sought to determine the role of dystroglycan, dystrophin's peripheral partner, at central synapses. I probed Northern blots of brain regions to delineate the distribution of brain β-dystroglycan mRNA and to uncover any β-dystroglycan-related transcripts in brain. Then, using subcellular brain fractions, and cultured hippocampal neurons, I determined that whereas α-dystroglycan is associated with central synapses, β-dystroglycan is not. This discovery is surprising, and differs from the finding that dystrophin and α- and β-dystroglycan colocalize at the presynaptic membrane of retinal photoreceptors.
In the course of the above mentioned work, using the anti-β-dystroglycan antiserum Ab98, I discovered a pair of proteins that were tightly associated with the postsynaptic density. These polypeptides of 58 kDa and 53 kDa (p58/53) were highly enriched in postsynaptic density (PSD) fractions from rat cerebral cortex, hippocampus, and cerebellum. In pursuit of a potential synapse-specific dystroglycan relative, I purified p58 and p53 by a combination of hydrophobic interaction chromatography and two-dimensional gel electrophoresis. Mass spectroscopy and peptide microsequencing revealed that p58/53 is identical to the insulin receptor tyrosine kinase substrate p58/53 (IRSp53). Whereas IRSp58/53 has no significant homology to β-dystroglycan other than the one span of peptides that confers its antibody cross-reactivity, its localization to the PSD newly implicates insulin signaling at synapses.
Analysis of IRSp58/53 mass profiles, peptides, and mRNA indicated that IRSp58 and IRSp53 are the product of the same coding sequence. Immunolocalization showed that IRSp58/53 is expressed in the synapserich molecular layer of the cerebellum. Immunostaining of cultured hippocampal neurons showed that both IRSp58/53 and insulin receptor are highly concentrated at synapses. Like IRSp58/53, insulin receptors are a component of the PSD fraction. Together, these data suggest that the synapse is a specialized site for insulin signaling in the brain.
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Bailey, Kelly M. "Focal adhesion kinase mediates caveolin-1 expression during epithelial to mesenchymal transition a novel pathway regulating aspects of cell motility in cancer /." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5804.
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Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains x, 229 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
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Lella, Divya Jyothi. "Functionalization and Modification of Naphthaquinone Analogs as HER2 Kinase Inhibitors." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1325.
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HER2 overexpression in breast cancer tumors predicts lower overall survival. Because of the aggressive nature of HER2 tumors and the association with metastatic disease, the HER2 receptor holds great promise as a therapeutic target in metastatic breast cancer. We are developing small molecule inhibitors that bind to the ATP binding site of the tyrosine kinase domain in order to inhibit tyrosine auto-phosphorylation. This process controls biological pathways that mediate the cell growth. In normal cells this process is highly controlled. We are targeting the modification of the side chain of the hydroxy methyl group of 2-Hydroxy methyl-5,8-dimethoxy-1,4-naphthaquinone. These compounds should inhibit the tyrosine kinase cascade of reactions thereby suppressing the overexpression of HER2 shutting down the tumor growth. The synthesis and characterization of a series of substituted naphthaquinone analogs with different increasing chain lengths will be reported.
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Macpherson, Iain Roderick James. "A study of p120-catenin and its tyrosine phosphorylation in cancer cell adhesion and invasion." Thesis, Connect to e-thesis, 2007. http://theses.gla.ac.uk/1008/.
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Fadeev, Andrey Verfasser], and Christiane [Akademischer Betreuer] [Nüsslein-Volhard. "The role of Tight Junction Protein 1a and Leukocyte Tyrosine Kinase in the development and organisation of pigment cells in the Zebrafish / Andrey Fadeev ; Betreuer: Christiane Nüsslein-Volhard." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1197695230/34.
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Fadeev, Andrey [Verfasser], and Christiane [Akademischer Betreuer] Nüsslein-Volhard. "The role of Tight Junction Protein 1a and Leukocyte Tyrosine Kinase in the development and organisation of pigment cells in the Zebrafish / Andrey Fadeev ; Betreuer: Christiane Nüsslein-Volhard." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1197695230/34.
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Bell, Kara Stephanie. "The role of individual protein kinase C isoforms in mast cell function and their targeting by the immunomodulatory helminth product, ES-62." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=23163.
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ES-62, a glycoprotein secreted by the filarial nematode Acanthocheilonema viteae, is immunomodulatory via subversion of signal transduction pathways operating in various immune system cells. With respect to human bone-marrow derived mast cells (BMMC), ES-62 has previously been shown to inhibit FcεRI-mediated degranulation by forming a complex with TLR4 to sequester PKC-α away from the plasma membrane, resulting in its degradation. An intriguing additional finding was that ES-62 reduced levels of other PKC isoforms, namely PKC-β, -δ, -I and -ζ. This project is concerned with establishing if PKC isoforms targeted by ES-62 are critical for BMMC functional responses and if so, whether the absence of any such isoform impacts on ES-62-mediated inhibition of mast cell responses. To establish the role, which each PKC isoform plays in mast cell function, PKC isoform knockout (KO) mice were employed. Simultaneously other types of immune system cell, namely macrophages and dendritic cells were explored, to establish whether any effects observed are mast cell-specific. The data obtained with mast cells indicate that control of pro-inflammatory cytokine production is possibly mediated by a partnership between one conventional and one novel isoform with PKC-α and more importantly, PKC-θ, acting as positive regulators of IL-6 and TNF-α production while on the other hand PKC-β and -ε act as negative regulators of IL-6 production. Although the loss of any one PKC isoform had no clear detrimental effects on ES-62 activity, the absence of PKC-θ may possibly dampen the nematode product's modulatory ability. The utilization of PKC-α, -β and -θ is specific for BMMC functional responses in comparison to macrophages whereby only PKC-ε was revealed as a positive regulator of IL-6. Interestingly however, PKC-α also appears to be an ES-62 target in macrophages. With respect to dendritic cells, in contrast to antigen-stimulated BMMC, PKC-α negatively regulates LPS-induced IL-6 and TNF-α.
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Leiras, Pedro Leonardo dos Santos David Torres. "Clínica e cirurgia de animais de companhia: mastocitoma canino." Master's thesis, Universidade de Évora, 2014. http://hdl.handle.net/10174/13513.
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O estágio curricular a que se refere o presente relatório, decorreu entre os dias 1 de Setembro de 2013 e 31 de Janeiro de 2014 no Hospital Veterinário do Baixo Vouga, sob a orientação científica do Dr. Hugo Vilhena. A área clínica com maior representatividade foi a clínica médica (79% dos casos). Na clínica médica, as doenças infecto-contagiosas e parasitárias foram as mais frequentes (16%), seguidas das doenças gastrointestinais e das glândulas anexas (14%). As únicas espécies observadas foram a canina (75%) e felina (25%). O mastocitoma canino é uma das neoplasias caninas mais comuns e a mais frequente na pele, embora possa desenvolver-se em outras localizações. O diagnóstico citológico é geralmente conclusivo. O comportamento biológico do mastocitoma é muito variável e, por isso, é complicado estabelecer o prognóstico. O sucesso do tratamento é muito dependente do seu comportamento biológico; Abstract:
Small animal medicine and surgery
This report describes the activities developed in the externship performed between September 1st, 2013 and January 31st, 2014 in the Baixo Vouga Veterinary Hospital, under the scientific supervision of Hugo Vilhena, DVM. The clinical area more represented was clinical medicine (79%). Within clinical medicine, infectious and parasitic diseases were the most common (16%), followed by the digestive system disorders (14%). The species attended were dogs (75%) and cats (25%).
Canine mast cell tumors are among the most common neoplasias of dogs, and it’s the most frequent of the skin, though it can arise in other locations. Cytological diagnosis is usually conclusive. Mast cell tumors biologic behavior is very variable. Due to that, establishing a correct prognosis may be difficult, and treatment may be unrewarding.
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Peterson, Cornelia WM. "Insulin Stimulates Protein Synthesis via RTK-Induction of the Akt-s6k Pathway in Human and Canine Corneal Cells." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555070124329814.
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Chen, Chun-Ti. "Regulation of the Cdc14-like Phosphatase CLP1 in Schizosaccharomyces pombe and Identification of SID2 Kinase Substrates: A Dissertation." eScholarship@UMMS, 2009. https://escholarship.umassmed.edu/gsbs_diss/449.
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Coordination of mitosis and cytokinesis is crucial to generate healthy daughter cells with equal amounts of genetic and cytoplasmic materials. In the fission yeast Schizosaccharomyces pombe, an evolutionarily conserved Cdc14-like phosphatase (Clp1) functions to couple mitosis and cytokinesis by antagonizing CDK activity. The activity of Clp1 is thought to be regulated in part by its subcellular localization. It is sequestered in the nucleolus and the spindle pole body (SPB) during interphase. Upon mitotic entry, it is released into the cytoplasm and localized to the kinetochores, the actomyosin ring, and the mitotic spindle to carry out distinct functions. It is not clear how Clp1 is released from the nucleolus, however, once released, a conserved signaling pathway termed Septation Initiation Network (SIN) functions to retain Clp1 in the cytoplasm until completion of cytokinesis. The SIN and Clp1 function together in a positive feedback loop to promote each other’s activity. That is, the SIN promotes cytoplasmic retention of Clp1, and cytoplasmic Clp1 antagonizes CDK activity and reverses CDK inhibition on the SIN pathway to promote its function and activity. However, at the start of this thesis, the mechanism by which the SIN regulated Clp1 was unknown. The SIN pathway is also required to promote constriction of the actomyosin ring, and the septum formation. However, its downstream targets were still uncharacterized. In two separate studies, we studied how Clp1 is released from the nucleolus at mitotic entry and how the SIN kinase Sid2 acts to retain Clp1 in the cytoplasm. We identified several Sid2 candidate substrates, and revealed other functions of the SIN pathway in coordinating mitotic events.
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Mayack, Shane Renee. "The role of Janus Kinase 3 in CD4+ T Cell Homeostasis and Function: A Dissertation." eScholarship@UMMS, 2004. https://escholarship.umassmed.edu/gsbs_diss/94.
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This dissertation addresses the role for Janus Kinase 3 (Jak3) in CD4+ T cell homeostasis and function. Jak3 is a protein tyrosine kinase whose activity is essential for signals mediated by the γc dependent cytokines IL-2, -4, -7, -9, -15, and -21. Previous data have demonstrated that peripheral CD4+ T cells from Jak3-deficient mice have a memory phenotype and are functionally impaired in both proliferative and IL-2 responses in vitro. Interestingly, Jak3/γc activity has been previously shown to play a role in the prevention of T cell anergy.
These studies were initiated to more precisely define the role for Jak3/γc cytokines in the prevention of T cell anergy and the maintenance of functional CD4+ T cell responses. We began to address this question by assessing global gene expression changes between wild type and Jak3-/- CD4+ T cells. These data indicate that Jak3-/- CD4+ T cells have an increase in gene expression levels of inhibitory surface receptors as well as immunosuppressive cytokines.
Further analyses confirmed that Jak3-deficient T cells express high levels of PD-1, secrete a Trl-type cytokine profile following direct ex vivo activation, and suppress the proliferation of wild type T cells in vitro. These characteristics indicate that CD4+ Jak3-/- T cells share properties with regulatory T cell subsets that have an important role in peripheral tolerance and the prevention of autoimmunity.
We next addressed whether these regulatory characteristics were T cell intrinsic or rather the result of expanding in a Jak3-deficient microenvironment characterized by a number of immune abnormalities and a disrupted splenic architecture. Jak3-/- CD4+ T cells proliferate in vivoin a lymphopenic environment and selectively acquire regulatory T cell characteristics in the absence of any additional activation signals. While the precise mechanism by which Jak3-deficient T cells acquire these characteristics remains unclear, our data indicate that one important component is a T cell-intrinsic requirement for Jak3 signaling.
These findings indicate several interesting aspects of T cell biology. First, these studies, demonstrate that the homeostatic proliferation of CD4+ T cells is not dependent on signaling via γc-dependent cytokine receptors. And, second, that the weak activation signals normally associated with homeostatic expansion are sufficient to drive Jak3-/- T cells into a non-conventional differentiation program. Previous data indicate that, for wild type T cells, signaling through both the TCR as well as γc-dependent cytokine receptors promote the homeostatic proliferation of T cells in lymphopenic hosts. Since Jak3-/- T cells are unable to receive these cytokine signals, their proliferation is likely to be wholly dependent on TCR signaling. As a consequence of this TCR signaling, Jak3-/- T cells proliferate, but in addition, are induced to up regulate PD-1 and to selectively activate the IL-10 locus while shutting off the production of IL-2. Since this fate does not occur for wild type T cells in a comparable environment, it is likely that the unique differentiation pathway taken by Jak3-/- T cells reflects the effects of TCR signaling in the absence of γc-dependent cytokine signaling.
Interestingly, wild type T cells undergoing homeostatic expansion in lymphopenic hosts show many common patterns of gene expression to freshly-purified unmanipulated Jak3-/- T cells. For instance, micro array analysis of gene expression in wild type CD4+ T cells after lymphopenia induced homeostatic expansion show a similar pattern of upregulation in surface markers (PD-1 and LAG-3), and cytokine signaling molecules (IL-10 and IFN-γ cytokine, receptors, and inducible gene targets) to that of Jak3-/- CD4+ T cells immediately ex vivo. These data suggest that the process of homeostatic proliferation normally induces immune attenuation and peripheral tolerance mechanisms, but that full differentiation into a regulatory T cell phenotype is prevented by γc-dependent cytokine signals.
Taken together these data suggest that Jak3 plays an important role in tempering typical immune attenuation mechanisms employed to maintain T cell homeostasis and peripheral tolerance.
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Lin, Mingqun. "Internalization and survival mechanisms of human ehrlichiosis agents ehrlichia chaffeensis and anaplasma phagocytophilum in host cells." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1054145222.
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Paula, Beatriz Quintino Rogado Mendes. "Padrão de expressão do recetor KIT no mastocitoma canino : seleção dos inibidores dos recetores tirosina quinase." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2018. http://hdl.handle.net/10400.5/16667.
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Dissertação de Mestrado Integrado em Medicina VeterináriaOs mastocitomas representam cerca de 11 a 27% de todas as neoplasias cutâneas malignas do cão. Devido à sua prevalência e comportamento biológico variável, ao custo da terapêutica e ao potencial stress emocional para os tutores, é importante realizar um prognóstico preciso dos mastocitomas cutâneos e selecionar corretamente a abordagem terapêutica mais apropriada. Vários fatores clínicos podem influenciar o curso da doença, no entanto, o fator de prognóstico mais importante é a gradação histológica. As mutações no c-kit e as alterações da expressão do KIT são conhecidas como indicadores de prognóstico negativo em mastocitomas cutâneos caninos. Além disso, animais portadores de mastocitomas com mutações no c-kit ou padrões de expressão anormais do KIT são potenciais candidatos à terapêutica alvo com inibidores dos recetores tirosina quinase (IRTQ). O principal objetivo deste estudo foi selecionar o melhor IRTQ para cada caso, com base no padrão de expressão do KIT. Um objetivo adicional foi a identificação e avaliação de fatores influenciadores de prognóstico, através de associações estatísticas e da análise de sobrevivência. Os 42 casos de animais com mastocitomas investigados foram, inicialmente, distribuídos por sexo, idade, raça, localização, tipo de lesão e grau histológico do tumor e, ainda, padrão de expressão do KIT. A idade do animal mostrou associação significativa com o grau histológico (p=0,0495) e a localização tumoral com o padrão de expressão do KIT (p=0,0271). Além disso, o risco de desenvolvimento de tumores com padrões do KIT atípicos foi superior nos animais com idades superiores a 8 anos, lesões múltiplas e tumores de alto grau histológico. Como bons indicadores influenciadores de prognóstico identificaram-se a idade no momento do diagnóstico (p=0,01) e o grau histológico do tumor (p=0,002). O risco de morte, relacionada com o mastocitoma, foi superior nos animais com tumores com padrões do KIT atípicos. As variáveis que apresentaram impacto significativo no tempo de sobrevivência foram a idade, o grau histológico, o tratamento quimioterápico e o tratamento com IRTQ. Foram, ainda, obtidos melhores resultados nas fêmeas e nos mastocitomas com padrão de expressão 1. Apesar das limitações do estudo, os resultados obtidos podem contribuir para o estabelecimento de um prognóstico e para a escolha da terapêutica a implementar em casos de mastocitoma cutâneo canino.
ABSTRACT - KIT expression in canine mast cell tumour: tyrosine kinase inhibitors selection - Mast cell tumours (MCT) are the most frequently diagnosed malignant skin neoplasm in dogs, representing up to 27% of all canine cutaneous neoplasms. Due to their prevalence and variable biologic behavior, the cost of therapeutics, and the potential emotional stress to owners, it is important to accurately prognosticate cutaneous mast cell tumours and to correctly select the most appropriate therapeutic approach. There are varied clinical factors that may influence the outcome; however, accurate histologic grading remains a cornerstone of MCT prognostication. Mutations in c-kit and altered expression of KIT have been shown to be negative prognostic indicators for canine cutaneous mast cell tumours. Furthermore, those mast cell tumours that have c-kit mutations or abnormal KIT expression are potential candidates for targeted therapy with tyrosine kinase inhibitors. The main goal of this study was to select the best tyrosine kinase inhibitor for each KIT expression pattern. An additional goal was the identification and evaluation of prognosis influencing factors, through statistical associations and survival analysis. The 42 mastocytomas investigated were initially distributed by sex, age, race, location, type of lesion, histological grade and KIT expression. The animal age showed a significant association with the histological grade (p = 0.0495) and the tumor location with the KIT expression (p = 0.0271). In addition, the risk of developing tumors with atypical KIT patterns was higher in animals aged over 8 years, with multiple lesions and tumors of high histological grade. The age at diagnosis (p = 0.01) and the histological grade of the tumor (p = 0.002) showed to be good prognostic indicators. The risk of death related to the mast cell tumour was higher in animals with tumors with atypical KIT patterns. The variables that had a significant impact on survival time were age, histological grade, chemotherapeutic treatment and treatment with tyrosine kinase inhibitors. Better results were also obtained in females and mast cells tumours with expression pattern 1. Lastly, despite the limitations of the study, the results obtained may be useful in establishing a prognosis and in the therapeutic choice in cases of canine cutaneous mast cell tumour.
N/A
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Althini, Susanna. "Experimental Studies of BMP Signalling in Neuronal Cells." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3398.
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Dong, Shen. "Caractérisation de deux nouveaux mécanismes de régulation de l'initiation du signal induit par le récepteur pour l'antigène du lymphocyte T." Paris 6, 2009. http://www.theses.fr/2009PA066163.
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Mes travaux montrent que la stimulation du récepteur pour l’antigène du lymphocyte T induit la phosphorylation sur tyrosine et le recrutement à la protéine d’échafaudage LAT de l’adaptateur inhibiteur Dok-2. Ce dernier et son homologue Dok-1 sont alors caractérisés comme modulateurs du signal précoce induit par l’engagement du TCR et comme régulateurs du seuil d’activation du lymphocyte T. Par ailleurs, j’ai montré que les lymphocytes T CD4+ naïfs présentent une activation basale de Lck et Fyn qui n’est pas augmentée après stimulation du TCR. L’inhibition stable de l’expression de LAT par interférence d’ARN messagers diminue l’activation de Lck et Fyn et la phosphorylation des substrats directs de Lck. Ces défauts de signalisation sont corrigés lorsque le TCR est engagé fortement. Ainsi, mes données indiquent que l’engagement du TCR entraîne la stabilisation du pool de Lck actif auprès de ses substrats de façon dépendante de LAT et de la force de stimulation.
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Atherly, Luana O. "The Role of ITK and RLK in CD8+ T Cell Development and Function: a Dissertation." eScholarship@UMMS, 2004. https://escholarship.umassmed.edu/gsbs_diss/120.
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Itk and Rlk are members of the Tec kinase family of non-receptor protein tyrosine kinases that are preferentially expressed in T cells. Numerous previous studies have demonstrated that these proteins play an important a role in the regulation of signalling processes downstream of TCR activation in CD4+ T cells, particularly in the phosphorylation of PLCγl. In addition, Itk and Rlk have both been shown to be important for CD4+ T cell development, differentiation, function and homeostasis following TCR activation. In the absence of Itk and Rlk, CD8+ SP thymocytes and T cells develop a memory/previously activated phenotypic profile, however, very little is known about the influence of Itk and Rlk on CD8+ T cell development and function. This study illustrates a previously unappreciated role for Itk and Rlk in the regulation of cytokine signals during CD8+ SP thymocyte maturation, and in the development of the memory CD44hi profile of Itk -/- and Itk -/- Rlk -/- CD8+ SP thymocytes and CD8+ T cells. This study also provides the first detailed study of the role of loss of Itk and particularly both Itk and Rlk in CD8+ signalling and function and shows that these Tec kinase family members play an important role in the maintenance of CD8+ T cell fitness and function, particularly in the ability of CD8+ T cells to accumulate in response to infection. Collectively, my studies demonstrate a critical role for Itk and Rlk in the generation of optimal CD8+ T cell responses. They also raise the novel observation that these proteins may be involved on the regulation of cytokine signals in T cells.
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Gozalo, Sara. "The Role of γс Cytokines in T Cell Development, T Cell Homeostasis and CD8+ T Cell Function: A Dissertation." eScholarship@UMMS, 2004. https://escholarship.umassmed.edu/gsbs_diss/140.
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T lymphocytes are essential components of the immune system and as such are continually regulated by a variety of factors. Every step of their development, survival and function is tightly monitored to ensure their ability to recognize most foreign agents and mount adaptive immune responses during pathogenic infections, while remaining tolerant to self-antigens. Among the many factors that participate in the regulation of T cell development and function are the cytokines. Cytokines that signal through the common gamma (γс) chain and the Janus kinase 3 (Jak3) include IL-2, -4, -7, -9, -15, and -21 and have been implicated in the regulation of every stage in the life of a T cell. Therefore, it is not surprising that mutations in the γс chain or Jak3 lead to a SCID condition in humans and mice. Specifically, Jak3-deficient mice are characterized by a reduction in thymic cellularity and dysregulated T cell homeostasis. They have an expansion of memory-like CD4+ mature T cells and an almost complete absence of mature CD8+ T cells. By investigating the TCR repertoire of CD4+ T cells in the thymus and spleen of Jak3-/- mice, I deduced that the CD4+ T cell activation and expansion is TCR-specific and takes place in the periphery of the mice. After crossing Jak3-deficient mice to Bcl-2 transgenic mice I showed that the developmental block observed in Jak3-/- mice could not be rescued by the anti-apoptotic factor, despite the fact that its expression did increase, slightly, the total numbers of developing thymocytes. The enforced expression of Bcl-2 was also not sufficient to revert the dysregulation of T cell homeostasis in Jak3-/- mice. Finally, in order to further understand the role played by γс cytokines during T cell function, I investigated the ability of mature Jak3-/- CD8+ T cells to become activated and differentiate into effector cells in response to a viral infection. My results indicate that CD8+ T cells are activated and proliferate in response to a viral infection, but their survival, as well as their ability to proliferate and differentiate into effector cells are greatly impaired, resulting in the inability of Jak3-deficient mice to mount a protective response.
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Lucas, Julie Ann. "The Role of Itk in T Cell Development: A Dissertation." eScholarship@UMMS, 2005. https://escholarship.umassmed.edu/gsbs_diss/91.
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Itk is a member of the Tec family of non-receptor tyrosine kinases. It is expressed in T cells, NK cells, and mast cells. The purpose of this study was to determine the role of Itk in T cell development. Previous work from our lab and others has demonstrated that Itk is involved in signaling downstream of the T cell receptor and initial analysis of Itk-deficient mice revealed that these mice had some defects in T cell development. There are two stages of T cell development, the pre-T cell stage and the CD4+ CD8+ double positive stage, at which signals downstream of the T cell receptor are important. At the CD4+ CD8+ double positive stage, these signals direct two concurrent, but distinct processes known as repertoire selection and CD4/CD8 lineage commitment/differentiation. I show that there are only slight defects in development at the pre-T cell stage, presumably due to reduced TCR signaling. However these results clearly demonstrate that Itk is not essential at this stage of development. In contrast, repertoire selection, in particular positive selection, is significantly affected by the absence of Itk. Similarly, I show that Itk plays a role in lineage differentiation, although commitment to the appropriate lineage occurs normally in the absence of Itk.
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Serdaroglu, Alperen Cagatay [Verfasser], Peer-Hendrik [Akademischer Betreuer] Kuhn, Kathrin [Gutachter] Lang, and Peer-Hendrik [Gutachter] Kuhn. "Development and application of methods for mass spectrometric analysis of acute myeloid leukemia derived cell lines to identify receptor tyrosine kinase inhibitor resistance mechanisms and serum biomarkers / Alperen Cagatay Serdaroglu ; Gutachter: Kathrin Lang, Peer-Hendrik Kuhn ; Betreuer: Peer-Hendrik Kuhn." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1155303350/34.
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Carie, Adam E. "Tumor suppressive effects of the Beta-2 adrenergic receptor and the small GTPase RhoB." [Tampa, Fla.] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002330.
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Chiarelli, Maria Catarina Silveira. "Perfil clínico-laboratorial e associação com fatores prognósticos de pacientes com leucemia linfocítica crônica." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/5964.
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Chronic Lymphocytic Leukemia is the primary lymphoid neoplasm in adults and and it is
especially manifested in the elderly. Because it is a heterogeneous disease it awakens great
interest regarding its prognosis. Rai and Binet developed staging systems to predict the
evolution of the disease and currently, the analysis of expression of CD38 and Zap-70 has
been investigated as a prognostic factor for indicating presence or absence of the mutation in
the gene IgVH, so, the objective of this study was to analyze the clinical and laboratory
profiles of patients with Chronic Lymphocytic Leukemia taking as reference the clinical
staging of Rai and Binet and quantification of CD38 and Zap-70 expression as prognosis
factors. We searched the medical records of 64 patients treated at University Hospital of Santa
Maria and the variables considered were swollen lymph nodes, presence or absence of
hepatomegaly and / or splenomegaly, hematological evaluation of peripheral blood and
immunophenotype. The data obtained were correlated with the staging of Rai (1975) and
Binet (1981), the expression of CD38 and Zap-70 and clinical stage. The results showed no
association between ataging Rai and Binet and the expression of CD38, Zap-70 and Binet
clinical staging.A Leucemia Linfocítica Crônica é a principal neoplasia linfóide em adultos e se manifeta principalmente em indivíduos idosos. Por ser uma doença heterogênea, desperta grande interesse quanto ao seu prognóstico. Rai e Binet desenvolveram sistemas de estadiamento capazes de prever a evolução da doença e atualmente, a análise da expressão de CD38 e Zap- 70 tem sido investigada como fator prognóstico por indicar presença ou ausência da mutação no gene IgVH, assim, o objetivo deste estudo foi analisar o perfil clínico-laboratorial dos pacientes com Leucema Linfocítica Crônica, tomando como referência os estadiamentos clínicos de Rai e Binet e a quantificação da expressão de CD38 e Zap-70 como fatores prognóstico. Foram pesquisados 64 prontuários médicos de pacientes atendidos no Hospital Universitário de Santa Maria e as variáveis consideradas foram aumento de linfonodos, presença ou ausência de hepatomegalia e/ou esplenomegalia, avaliação hematológica de sangue periférico e imunofenótipo. Os dados obtidos foram correlacionados com o estadiamento de Rai (1975) e Binet (1981), a expressão de CD38 e Zap-70 com o estádio clínico de Binet. Os resultados demonstraram que não há associação entre o estadiamento de Raí e Binet e a expressão de CD38, Zap-70 com o estadiamento clínico de Binet.
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Frey, Margo Tilley. "Development of a Substrate with Photo-Modulatable Rigidity for Probing Spatial and Temporal Responses of Cells to Mechanical Signals: A Dissertation." Digital WPI, 2008. https://digitalcommons.wpi.edu/etd-dissertations/337.
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"Topographical and mechanical properties of adhesive substrates provide important biological cues that affect cell spreading, migration, growth, and differentiation. The phenomenon has led to the increased use of topographically patterned and flexible substrates in studying cultured cells. However, these studies may be complicated by various limitations. For example, the effects of ligand distribution and porosity are affected by topographical features of 3D biological constructs. Similarly, many studies of mechanical cues are compounded with cellular deformation from external forces, or limited by comparative studies of separate cells on different substrates. Furthermore, understanding cell responses to mechanical input is dependent upon reliable measurements of mechanical properties. This work addresses each of these issues. To determine how substrate topography and focal adhesion kinase (FAK) affect cell shape and movement, I studied FAK-null (FAK -/-) and wild type mouse 3T3 fibroblasts on chemically identical polystyrene substrates with either flat surfaces or micron-sized pillars, I found that, compared to cells on flat surfaces, those on pillar substrates showed a more branched shape, an increased linear speed, and a decreased directional stability, which were dependent on both myosin-II and FAK. To study the dynamic responses to changes in substrate stiffness without other confounding effects, I developed a UV-modulatable substrate that softens upon UV irradiation. As atomic force microscopy (AFM) proved inadequate to detect microscale changes in stiffness, I first developed and validated a microsphere indentation method that is compatible with fluorescence microscopy. The results obtained with this method were comparable to those obtained with AFM. The UV-modulatable substrates softened by ~20-30% with an intensity of irradiation that has no detectable effect on 3T3 cells on control surfaces. Cells responded to global softening of the substrate with an initial retraction followed by a gradual reduction in spread area. Precise spatial control of softening is also possible - while there was little response to posterior softening, anterior softening elicited a pronounced retraction and either a reversal of cell polarity or a significant decrease in spread area if the cells move into the softened region. In conclusion, these techniques provide advances in gaining mechanistic insight into cellular responses to topographical and mechanical cues. Additionally, there are various other potential applications of the novel UV-softening substrate, particularly in regenerative medicine and tissue engineering. "
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Pinheiro, Liliane Sena. "Análise da expressão de isoformas de proteína quinase C em células cromafins da medula adrenal de ratos Wistar diabéticos tratados e não tratados com insulina." Universidade Federal de Juiz de Fora (UFJF), 2008. https://repositorio.ufjf.br/jspui/handle/ufjf/2853.
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O diabetes mellitus (DM) reduz a secreção de catecolaminas (CAs) das células cromafins adrenais, sendo esse um evento patofisiológico crítico por favorecer a ocorrência de episódios de hipoglicemia grave decorrentes do próprio tratamento da doença. Vários trabalhos relatam a participação de proteínas quinase C (PKCs) nas vias de síntese e secreção de CAs nas células cromafins. Os objetivos desse trabalho foram analisar o efeito do DM sobre a expressão das isoformas α, ε e ζ de PKC em células cromafins de ratos e avaliar se o controle glicêmico reverte os efeitos da doença. Foram utilizados ratos Wistar com DM induzido por estreptozotocina. Foram estabelecidos três grupos experimentais, ratos controles (C), diabéticos tratados com salina (DTS) ou com insulina (DTI). As análises foram feitas 15 dias após a indução. Utilizamos as técnicas de imunohistoquímica e Western Blot. A insulinoterapia foi estabelecida após estudos do comportamento alimentar e da variação dos níveis glicêmicos de ratos controles e doentes durante 24h consecutivas. Foi testada a eficácia de diferentes esquemas de tratamento com insulina. O tratamento estabelecido consistiu em injeções de insulina NPH, sendo 1U aplicada às 13h e 4U às 19h. Após os 15 dias de tratamento, o ganho médio de massa corporal dos ratos C (+37±3g) e DTI (+43±3g) foram similares enquanto os DTS emagreceram (-9±6g). A média da glicemia de jejum dos ratos C (74±1mg/dl) e dos DTI (93±6mg/dl) foram similares e dentro dos níveis normais, enquanto que a dos ratos DTS foi elevada (471±23mg/dl). A insulinoterapia restabeleceu os níveis plasmáticos do colesterol total, c-LDL e c-VLDL nos ratos DTI. O DM não alterou os níveis de c-HDL, triglicerídos e frutosamina. As análises da expressão de PKCs mostraram que a PKCα é a mais expressada seguida de ζ e depois de ε. O DM reduziu em 39,5% a expressão da PKCα, enquanto a de ζ foi aumentada em 74,2%. A expressão da PKCε não foi afetada pelo DM. O tratamento com insulina reverteu o efeito do DM sobre a expressão de PKCα, a expressão da PKCε continuou inalterada e a expressão da PKCζ permaneceu elevada (+32,6%) quando comparada aos ratos C. Concluímos que em células cromafins adrenais, o diabetes afeta a expressão de isoformas de PKCs de maneira diferenciada. Trabalhos realizados em nosso laboratório mostraram que o DM reduz o conteúdo total (21,1%), a secreção basal (-24,3%) e a estimulada por carbacol (-28,9%) e K+ (42,2%) de CAs. Como observado para PKCα, a insulinoterapia reverteu o efeito do DM sobre o conteúdo total. Já foi demonstrado que PKCα participa de uma via de sinalização que estimula a atividade de tirosina hidroxilase. Por outro lado, o tratamento não restabeleceu os processos secretórios, sugerindo que PKCζ possa estar envolvida nessa alteração. Há fortes evidências de que PKCζ regula canais de K+ retificadores, o que pode explicar o efeito da doença sobre o processo de secreção via despolarização da membrana.
The diabetes mellitus (DM) reduces the catecholamine (CAs) secretion of adrenal chromaffin cells, a critical pathophysiologic event that promotes the occurrence of serious hypoglycemia episodes, consequence of the disease treatment. Several papers report the participation of protein kinase C (PKC) on catecholamine synthesis signal pathways of adrenal chromaffin cells. The objectives of this work were to study the effect of DM on expression of PKC isoforms α, ε and ζ in rat chromaffin cells and to evaluate if the glicemic control revert the effect of the illness. Male Wistar rats with diabetes induced by streptozotocin were used. Three experimental groups were determined: Control (C), diabetic rats receiving saline solution (DS) and diabetic rats receiving insulin (DI). The analyses were made after 15 days of DM induction. Immunohistochemistry and western blotting techniques were done. The insulin therapy protocol was established after studying the feeding behavior and glycemic level variations during the whole 24h. The information made possible to establish the time of insulin applications. Several schemes of insulin treatments were tested to keep the diabetic rat as close as possible to normoglycemia path. The best results were found by using 1U at 1:00 PM and 4U at 7:00 PM of NPH insulin. After 15 days of treatment the acquired body weight was similar between C and DI rats, 37±3g and 43±3g, respectively. The DS rats emaciated 9±6g. The fasting glycemic levels were 74±1mg/dl, 93±6mg/dl and 471±23mg/dl to C, DI and DS rats, respectively. The insulin therapy reestablishes the plasmic levels of total cholesterol, c-LDL and c-VLDL on DI rats. The DM did not change the levels of c-HDL, triglycerides and frutosamine. The PKCα is the more expressed isoform in adrenal chromaffin cells, followed by ζ and ε. The DM reduced 39,5% the PKCα expression and, unlike, increased 74,2% the expression of PKCζ. The expression of PKCε was not affected by DM. The insulin treatment reverted the effect of DM on PKCα, the expression of PKCε remained unchanged and the expression of PKCζ remained higher than the control group (+32,6%). Studies of our laboratory show that the DM causes reduction on adrenal catecholamine content (21,1%), basal secretion (-24,3%) and catecholamine secretion stimulated by carbachol (-28,9%) and high K+ (-42,2%). The insulin therapy, in like manner as observed on PKCα, reverted the DM effect on adrenal catecholamine content. It was shown that PKCα participates on signal transduction pathway that stimulates the activity of tyrosine hydroxylase. Otherwise, the insulin treatment did not restore the secretory processes, suggesting that PKCζ could be involved in this process. There are strong evidences showing that PKCζ regulates the voltage-dependent delayed rectifier K (Kv) and its expression was not normalized by insulin therapy.
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Cochonneau, Stéphanie. "Modulating hematopoietic progenitor cell engraftment and T cell differentiation : role of conditioning and route of administration." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20226.
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Les déficits lymphocytaires T peuvent être corrigés par l'administration en intraveineuse (IV) de cellules souches hématopoiétiques (CSH) provenant d'un donneur. Dans un modèle d'immunodéficience lié à l'absence de la protéine kinase ZAP-70, notre équipe avait précédemment montré que l'injection intrathymique (IT) de CSH histocompatibles conduit à une reconstitution du compartiment T plus robuste et plus rapide que dans le cas où les CSH sont administrées par voie IV. Au cours de ma thèse, je me suis intéressée à l'approche IT dans un contexte non-histocompatible, où j'ai montré que l'injection de CSH semi-allogéniques directement dans le thymus permet le développement d'une thymopoièse à long-terme, même en absence de conditionnement. De plus, j'ai également montré la persistence de progéniteurs thymiques précoces (ETP) provenant du donneur dans le thymus des souris transplantées. De façon remarquable, ces ETP retiennent un potentiel de différenciation plus divers que ceux rencontrés dans le thymus d'une souris sauvage, et leur fréquence est significativement élévée après IT, ce dernier suggérant une disponibilité accrue des niches thymiques. De façon intéressante, j'ai également montré que les progéniteurs déficients en ZAP-70 pouvaient se différencier de façon importante vers le lignage CD8 lors d'une activation constante de la voie de signalisation Notch couplée à la présence d'interleukine 7 (IL-7). Après la greffe de CSH par voie IV de souris ZAP-70-/-, en absence de conditionnemt, j'ai également identifié l'accumulation d'une population de CSH présentant un phénotype particulier (Lin- Sca 1+ c-kit-), nommée LSAPT. Ces cellules LSAPT présentent un biais de différenciation vers le lignage T γδ ainsi qu'une production élevée d'IL-17, ce qui suggère que les fonctions effectrices d'une cellule T γδ sont dépendantes de leur origine progénitrices. L'ensemble de mes résultats apporte à la fois de nouveaux éléments concernant l'identification de progéniteurs T et démontrent de l'influence/coopération entre voies de signalisation et facteurs environnementaux dans la modulation de la différenciation T et de leur fonctions effectricesT cell deficiencies can be corrected by the intravenous (IV) injection of donor hematopoietic stem cells (HSCs). Using a murine model of ZAP-70-/- deficiency, our group previously showed that the intrathymic (IT) administration of histocompatible HSCs leads to a more robust and long-term thymopoiesis as compared to that achieved by the classical IV route. During my PhD, I found that the direct IT administration of semiallogeneic HSCs results in a sustained donor-derived thymopoiesis, overcoming histocompatibility barriers, even in the absence of conditioning. Furthermore, I found that donor-derived early thymic progenitors (ETPs) persist in the thymi of ZAP-70-/- transplanted mice, and present increased multi-lineage potential as compared to wild-type ETPs. Importantly, the frequency of donor-derived ETPs was augmented following IT transplantation, indicative of an increased progenitor niche. Interestingly, ZAP-70-deficient HSC could themselves be driven to a CD8 lineage fate in an environment where IL-7 potentiates continuous activation of the Notch pathway. Following IV transplantation of donor HSC into non-conditioned ZAP-70-/- mice, I determined that there is an accumulation of lineage-/Sca1+ donor progenitors lacking expression of the stem cell marker c-kit, termed LSAPT. These LSAPT show a biased differentiation towards the γδ T cell lineage with high IL-17-producing effector function, suggesting that progenitor origin regulates γδ T cell fate. The ensemble of my experiments provide new insights into the identity of T lineage progenitors and demonstrate how signaling pathways as well as environmental factors modulate T cell differentiation and effector function