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Immune Tolerance Kyeong Cheon Jung Department of Pathology Seoul National University College of Medicine
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Immune tolerance Unresponsiveness to an antigen that is induced by previous exposure to that antigen Self tolerance: The normal lack of the ability to produce an immunological response to autologous (self) antigens. Transplantation tolerance : the specific absence of a destructive immune response to a transplanted tissue in the absence of immunosuppression Abbas: Cellular and Molecular Immunology 7E
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Self tolerance Central tolerance Negative selection Receptor editing Generation of regulatory T cells Peripheral tolerance Clonal anergy Clonal deletion Regulatory T cells T-T interaction Abbas: Cellular and Molecular Immunology 7E
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Thymocyte Development Nat Immunol. 2006;7:338-334
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Central tolerance of T cells Regulaotry T cells
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Negative selection: mTEC vs DCs Trends Immunol 2002, 23:364-371
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AIRE (Autoimmune Regulator) A gene or its encoded protein, which functions to stimulate expression of peripheral tissue protein antigens in medullary thymic epithelial cells
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AIRE & promiscuous gene expression Trends Immunol. 2002, 23:364-71
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AIRE & central Tolerance Role of AIRE in self antigen presentation Induction of promiscuous gene expression Induction of antigen presentation Role of AIRE + mTEC Clonal deletion Treg induction Role of DC Uptake & presentation of antigen from AIRE + mTEC negative selection
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Defect in AIRE gene autoimmune polyendocrinopathy- candidiasis- ectodermaldystrophy (APECED), autoimmune polyglandular syndrome type 1 (APS-1) AIRE knock-out mouse
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Defect in central tolerance: Qualitative difference Nat Med 2000, 6:56-61 B6 SJL Thymus Brain EAE
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Manifestation of APS-1
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Clonal anergy: functional unresponsiveness Clonal deletion: cell death Active suppression by regulatory T cells T-T interaction Peripheral tolerance
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T cell anergy in the absence of co- stimulatory signals
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Costimulatory vs. inhibitory moleccules B7-2 (CD86) : CD28 B7-1 (CD80) : CD28 CD40 : CD40L (CD154) ICOSL : ICOS CD70 : CD27 OX40L (CD134L) : OX40 (CD134) 4-1BBL : 4-1BB B7-2 : CTLA-4 B7-1 : CTLA-4 PD-L1, PD-L2: PD-1 Costimulation (APC : T cell) Inhibition (APC : T cell)
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Circ Res. 2008, 103:1220-1231
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CTLA-4/B7 vs. CD28/B7 Interaction Immunity, 1997, 7: 445-450
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Immune dysregulation in human subjects with heterozygous mutations in CTLA4 Science, 2014, 345: 1623-1627
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Development of abatacept & belatacept J Allergy Clin Immunol 2008, 121:299
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PD-1–PD-L pathway contributes directly to T cell dysfunction during chronic viral infection Nat Immunol 2007, 8:239
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PD-L1 KO mice infected with chronic form of virus Nature 2006, 439:682-687
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PD-1–PD-L pathway in peripheral tolerance Am J Transplant. 2012;12:2575-87
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PD-1 signaling Immunol Rev 2010; 236:219-242
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Autoimmunity vs. anti-cancer immunity Anti-CTLA-4: Ipilimumab Anti-PD-1: Pembrozumab http://melanomamissionary.blogspot.com
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Adverse Events in Patients Receiving Anti–PD-L1 Antibody N Eng J Med 2012, 266:2455-2465
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Vitiligo caused by anti-CTLA-4 antibody therapy http://www.ascopost.com/issues/october-15,-2013/how-to-recognize-and-manage-ipilimumab -induced-dermatologic-adverse-events.aspx
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Activation induced cell death (AICD)
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Regulatory T cells: Subsets nTregiTregTr1Th3 Phenotype CD25++-++ CD103-++-- GITR++++-? CTLA-4+++++++++ Foxp3++++-/+- Cytokine secretion IL-10+/-++++++ TGF- +++++ Differentiation factors TGF- , RAIL-10, IFN- TGF- , IL-4 Suppression mechanism In vitroDiverse Diverse IL-10, TGF- TGF- In vivoDiverse Diverse IL-10, TGF- TGF- Modidifed from J Leukoc Biol. 2006, 80:458-470 & J Immunol 2003, 171:6323-6327
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Yan Xing, and Kristin A. Hogquist Cold Spring Harb Perspect Biol 2012;4:a006957 ©2012 by Cold Spring Harbor Laboratory Press Differential TCR signalling in negative selection and Treg cell differentiation
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Basic mechanisms used by Treg cells Nat Rev Immunol. 2008, 8:523-532 *IDO, indoleamine 2,3-dioxygenase
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Induction of iTreg by cytokines TCR stimulation + IL-2 + TGF- iTreg Retinoic acid TGF- + IL-6 Th17 TGF- + RA Treg CD103 + DC in gut: retinal dehydrogenase RA Treg (J Exp Med 2007, 204:1757-1764)
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Treg deficientyFoxp3 Mutation Foxp3 mutation In human: IPEX (Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome) Mouse: Scurfy mutant IL-2/IL-2R deficiency TGF deficiency
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Immune regulation by T-T interaction Idiotype-anti-idiotype network TCR peptide presentation via MHC I or II molecules Immune suppression by anti-idiotype T cells Ergotype-anti-ergotype network CD25 or HSP60 peptide presentation by MHC class I or II molecules Immune suppression by anti-ergotypic T cells
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Induced tolerance Front Immunol. 2012;3:274
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Arrest of DC maturation in semimature stage via MD-3 Ab treatment - in vitro surface molecules -
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Arrest of DC maturation in semimature stage via MD-3 Ab treatment - in vitro cytokine secretion -
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Prolongation of porcine islet xenograft survival in humanize mice via MD-3 treatment
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Control Ab MD-3 H&EInsulinCD3CD68 D Lack of immune cell infiltration in islet xenograft of MD-3-treated group
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Long-term survival of islet xenograft in Rhesus monkeys via combined therapy
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Self tolerance Central tolerance Negative selection Receptor editing Generation of regulatory T cells Peripheral tolerance Clonal anergy Clonal deletion Regulatory T cells T-T interaction Abbas: Cellular and Molecular Immunology 7E
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