分子免学T细胞亚群 2014硕士.ppt

* * * strong TCR signals have been demonstrated to transiently inhibit IL-2-driven STAT5 activation despite abundant production of IL-2 by activated CD4+ T cells, thereby blocking Th2 development * * Conventional Th17 cell development Immunologic Review , 2013 Follicular helper T cells (TFH) Preferentially resident in B cell follicles Express CXCR5, a early defining marker Produce a large amount of IL-21, which acts in an autocrine manner together with IL-6 promote their differentiation and expansion Depend on the Bcl-6 transcription factor Essential for the generation of high-affinity isotype switched antibodies and B cell memory Anatomical localization and cellular requirements for Tfh cell generation JEM, 2012 JEM, 2012 Anatomical localization and cellular requirements for Tfh cell generation CD4+CD25+ Regulatory T cells (Treg cells) A subset of CD4+ CD25+ T cells expressing Foxp3 Naturally present in immune system, constitute 5-10% of peripheral CD4+ T cells Suppress immune responses and maintain self-tolerance Sakaguchi et al. Immunologic self-tolerance maintained by activated T cells expressing IL-2 receptor alpha-chains (CD25). Breakdown of a single mechanism of self-tolerance causes various autoimmune diseases. J Immunol 1995 The Discovery of CD4+CD25+ Treg cells Identify CD25 as a surface marker The discovery of Foxp3 and its role in CD4+CD25+ Treg Hori et al. Control of regulatory T cell development by the transcription factor Foxp3. Science 2003 Fontenot et al. Foxp3 programs the development and function of CD4+CD25+ regulatory T cells. Nature Immunol 2003 R. Khattri, et al, An essential role for Scurfin in CD4+CD25+ T regulatory cells, Nat. Immunol. 4 (2003), pp. 337–342. Natural Treg cells (nTreg) Thymic derived, highly controlled by thymic microenvironment Induced Treg cells (iTreg) Peripherally generated from Foxp3-CD4+T cells differentiated under more varied conditions Subsets of Treg cells