移植免疫2013

1,中南大学湘雅医学院免疫教研室田 伟 博士， 教授,第 18章 移 植 免 疫,Transplant Immunology,2,Allografts: transplants from a genetically unrelated donor of the same species. Allogeneic transplantation: the last resort for the treatment of chronic organ failure. the major complication post-transplantation is rejection. Rejection occurs in almost all transplant recipients, to varying degrees.,3,E.D.Thomas,J E. Murray,1954年，JE.Murray首次施行同卵双生姐妹之间的肾移植。1956年，E.D.Thomas首次给一位白血病患者进行骨髓移植.Murray和Thomas的工作标志器官移植成为临床疾病治疗的手段。,4,Antigen independent mechanisms,Peritransplant ischemiaMechanical traumaReperfusion injury,6,Peritransplant injury induces chemokines that increase inflammation and immunity,7,Content,Immunological mechanism in allogeneic graft rejectionTypes of transplant rejection Principles to prevent transplant rejection Trends and advances in experimental transplant immunology,8,9,器官移植排斥的本质：一种免疫应答过程。自体/同系移植不排斥，同种异体移植排斥。首次排斥（术后10-13天）,再次排斥（6-8天）。再次移植无关个体皮肤，排斥时间为10-13天。移植到裸鼠，排斥（-）；输入无关个体T细胞， 则排斥（+）。,10,第1节 同种异体移植排斥的机制,11,Types of transplantation,Autologous (自体移植）Syngeneic（同系移植） Allogeneic（同种移植） Most commonXenogeneic（异种移植）,12,ACCEPTED,REJECTED,Genetic basis of transplant rejection,Transplantation of skin between strains showed thatrejection or acceptance was dependent uponthe genetics of each strain,13,Transplant rejection is due to an antigen-specific immune responsewith immunological memory.,Immunological basis of graft rejection,14,Immunogenetics of graft rejection,Mice of strain (A x B) are immunologically tolerant to A or B skin,ACCEPTED,REJECTED,Skin from (A x B) mice carry antigens that are recognised as foreign by parental strains,15,Histocompatibility and graft survival,16,一.引起同种移植排斥反应的抗原,人类主要组织相容性抗原（HLA)HLA型别的差异是发生移植排斥反应的主要原因.,17,HLA antigens:The HLA genes represent the most polymorhic genetic system in humans.Usually multiple alleles at the classical HLA loci exist in the human population . Non-synonymous substitution results in allotype antigen.,18,Simplified map of the HLA region,Maximum of 9 types of antigen presenting molecule allow interaction with a wide range of peptides.,PolygenyCLASS I: 3 types HLA-A, HLA-B, HLA-C (sometimes called class Ia genes),CLASS II: 3 types HLA-DP HLA-DQ HLA-DR.,19,IMGT/HLASequence Database StatisticsAllele Information HLA Class I Alleles: 1,156HLA Class II Alleles: 712HLA Alleles: 1,868Other Alleles: 67（Including 56 MICA alleles),20,Polymorphism in MHC Class I genes,Variation 1% at a single genetic locus in a population of individualsIn the human population, over 1300 MHC class I alleles have been identified - some are null alleles, synonyms or differ in regions outside the coding region,Data from .uk/HIG/index.html September 2005,1318 alleles(998 in October 2003)(657 in July 2000),21,Polymorphism in MHC Class II genes,Over 700 human MHC class II alleles have been identified - some are null alleles, synonyms or differ in regions outside the coding region,22,次要组织相容性抗原（minor Histocompatibility antigens, mH抗原）与性别相关的mH抗原Y染色体基因编码的H-Y抗原.非Y染色体连锁的mH抗原(HA-1HA-5),mH抗原,MHC 限制分子,群体表型频率,TCR谱,H-Y,HLA-A1,A2,B7,B60,50%,可变,HA-2,HLA-A2,95%,HA-4,HLA-A2,16%,?,可变,23,Identification of the Minor Histocompatibility Antigen HA-1Correlates with the development of severe graft versus host disease (GvHD) after human leukocyte antigen-identical bone marrow transplantation. Derived from nonapeptide of an allele of the KIAA0223 gene.,24,KIAA0223 gene forms a diallelic system.The two alleles differ in: Two nucleotides A single amino acid.,25,VLHDDLLEA is encoded by an allele HA-1H.VLRDDLLEA is encoded by an allele HA-1R.,26,HA-1 (HA-1H) has a population frequency of 69%.HA-1R represents the HA-1-negative allelic counterpart with a frequency of 31% in the population.,27,Peptide HA-1R (VLRDDLLEA) could not be detected in the HLA-A*0201-eluted peptides.The binding affinity of peptide HA-1R (VLRDDLLEA) was 1/12 of that of peptide HA-1H (VLHDDLLEA) for HLA-A*0201.,28,Peptides can be eluted from MHC molecules,29,The absence of the HA-1 R peptide in HLA-A*0201 suggests that this allele can be considered as a null allele with regard to HLA-A*0201-restricted T cell reactivity.This further suggests that only BMT from an HA-1R/R donor to an HA-1H/H or HA-1H/R recipient and not the reverse would be significantly associated with GvHD.,30,mH抗原的识别具有MHC限制性.不同类型mH抗原结合HLA分子及被递呈能力不同.所引起排斥反应通常较轻，速度较慢.HLA相同时移植排斥反应(如GVHD)的主要因素.,mH抗原诱导同种异型排斥反应的特点,31,其它参与排斥反应的抗原人类ABO 血型抗原表达于红细胞,肝,肾组织细胞,血管内皮细胞的表面.不合导致超急性排斥反应.组织特异性抗原表达于特定器官，组织或细胞表面.内皮细胞特异性（VEC)抗原.SK 抗原：皮肤蛋白多肽抗原.,32,CytokinesTNF-a,IL-10 Mediator of immune responseSNP polymorphism, high or low producers Cytokine receptorsAdhesion molecules Co-stimulatory moleculesGenetic variability influencing allograft survival may reaches beyond that of the MHC molecules.,Other factors involved in the immune response to an allograft,33,二、T细胞识别同种抗原的机制,34,受者T细胞,供者APC,供者APC,受者T细胞,受者TCR,供者MHC,T细胞TCR直接识别过路细胞表面完整的同种异型MHC分子,无需经过自身APC处理,无需自身MHC分子参与递呈.,供者肽,移植排斥反应中的直接同种异型识别,（一）直接同种异型识别,35,Recognition of Alloantigens,Direct PresentationRecognition of an intact MHC molecule displayed by donor APC in the graft,36,Activation of Alloreactive T cells and Rejection of Allografts,Donor APCs migrate to regional lymph nodes and are recognized by the recipients T cells .Alloreactive T cells in the recipient are activated and they migrate into the graft and cause graft rejection.,37,38,HOST,CD8+T细胞对异型MHC分子的直接识别,39,40,直接同种异型识别特点,过路细胞(Passenger Cell)：移植物残留的成熟树突状细胞,巨噬细胞。表达MHC-I,II 类分子和B7辅助刺激分子。排斥反应速度快强度大作用阶段急性排斥反应对免疫抑制药物敏感,41,间接识别Indirect allo-recognition受者T细胞识别经过受者APC加工处理的来源于移植物的MHC分子（肽段）或mH 抗原,受者T细胞,TCR,供者抗原肽,受者MHC,受者APC,（二）间接同种异型识别,42,Indirect Presentation Donor MHC is processed and presented by recipient APC Basically, donor MHC molecule is handled like any other foreign antigen,43,HOST,44,Cellular Immune Response (Early Stage in acute rejection) 1.Th1 Activation 2.Activation of CD8+ CTL 3.Release of cytokines, chemokinesHumoral Immunity (In Super Acute Rejection) 1.Opsonization 2 ADCC 3 CDC,Immunological Mechanisms,45,Renal Transplant Rejection HyperacuteAcuteTubulointerstitialVascularChronic,第2节 移植排斥反应的类型,I.HVGR（宿主抗移植物反应),46,Hyperacute Rejection,Caused by preformed antibodies in the recipientOccurs within minutesGrossly kidney purple and swollenWidespread acute arteritis and arteriolitisThrombosis of vesselsIschemic necrosisResults in loss of graft,47,Hyperacute rejection,Source of pre-existing antibody: Repeated blood transfusions Repeated pregnancies Previous graft,Blood Ag : ABO Ag,48,Hyperacute rejection: Thrombi in glomerulus and fibrin in artery. Anti-donor antibodies bind to donor endothelial cells and activate the complement cascade and clotting cascade.,Fibrin in artery,Thrombus in Glomerulus,49,Acute Rejection,Occurs as early as 10-14 days. May occur months to years later.CD4 T mediated DTHEffector cells:CD4 T,CD8 T,NK cellDecreased renal function. May have fever and tenderness of the graft.Tubulointerstitial or vascular,50,Acute tubulointerstitial rejection: Mononuclear interstitial infiltrate.,51,Chronic Rejection,After fourth monthVascular changesIntimal fibrosisProgressive luminal narrowingInterstitial fibrosis and tubular atrophyIschemic glomerulosclerosisNo effective therapy,52,Chronic Transplant Vasculopathy Concentric Fibrous Intimal Thickening,53,II.GVHR（移植物抗宿主反应）移植受者免疫功能极度低下时，由移植物中的抗原特异性淋巴细胞识别宿主组织抗原所发生的一种严重的排斥反应。,第2节 移植排斥反应的类型,54,宿主免疫功能低下；移植物含足够免疫活性细胞；识别受者MHC抗原、mH抗原；产生针对宿主组织器官损伤；主要见于异基因骨髓移植。,55,Complications of Allogeneic BM Transplants,Graft versus host diseaseImmunologically competent cells from donorAffects liver, skin, gut (jaundice, rash, diarrhea)Acute or chronicGraft versus leukemia effect may be beneficialRejection of allogeneic marrow cells.,56,Acute GVHR,57,移植物抗白血病效应Graft versus leukemia effect,BMT(同卵双生，自体移植）:无GVHD，高复发率。Allo-BMT:复发率明显减少。,58,NK cells express inhibitory receptors that are specific for MHC class I alleles . In humans these molecules are known as Killer Immunoglobulin-like Receptors (KIRs).,59,移植物NK细胞杀伤受者残留肿瘤细胞,KIR 基因具有高度的群体遗传多样性，主要表达于NK 细胞,T 细胞亚群的细胞膜表面.KIR：HLA-I 分子形成受体：配体关系.主要产生抑制信号，调节NK 细胞的活化,60,HLA genes are located on chromosomeat lociKIR genes are located at,6p21.3,19q13.4,61,供受体可能出现HLA相同，而KIR 不合的情况.相应KIR受体分子或HLA-I配体分子的缺如，将改变NK 活化阈值.,62,Lysis,Lysis,leukemia,DC,DC,DC,Donor alloreactiveNK cells,Lysis,T,T,T,Kill recipient APCs =protection from GvHD,Kill recipient T cells =improved engraftment,Kill leukemia =GvL effect,NK Cells for Stem Cell Transplantation,63,Alloreactive NK cells could be deliberately infused to prevent leukemic relapses. Alloreactive NK cells kill the host dendritic cells (DCs). Removal of DCs prevents the presentation of host antigens to graft T cells which is the crucial step in initiating GvH reactions.,64,Immune privilege in the cornea,Keratoplasty is the oldest and one of the most successful forms of solid tissue transplantation. Does not require the aid of tissue typing or systemic immunosuppressive drugs.,65,Contributing factors Expression of MHC class I molecules is markedly reduced . There is no constitutive expression of MHC class II molecules .Lacks both blood and lymph vessels. Lacks bone marrow-derived antigen-presenting cells (APC).,66,第3节 移植排斥反应的防治原则,67,Methods of Increasing Graft Survival,Screening of preformed allo-antiboby. ABO blood groups Panel reactive antibodyHLA matching. Crucial for Allo-BMT SNPs typing Oligonuleotide Microarrays mH antigenImmunosuppression of the recipient.,68,HLA matching and graft survival,69,Tissue typing: the MLR scheme,MLR: Mixed Lymphocyte Reaction,70,71,PRA (panel reactive antibody)来源：输血、妊娠、移植、透析治疗、疾病（SLE）。种类：IgG、IgM、IgA、自身抗体。参与超急性排斥反应。,72,免疫抑制疗法免疫抑制药：环孢素A、FK506、雷帕霉素.生物制剂：针对免疫细胞膜抗原的各种抗体.抗淋巴细胞球蛋白（ALG）,抗胸腺细胞球蛋白（ATG）,Anti-CD3，Anti-CD4，Anti-CD8 mAb.通过CDC机制清除体内的T细胞或胸腺细胞.,73,74,75,第4节 移植相关的免疫学问题,诱导同种移植耐受的主要策略,76,长期存活移植受者体内含有供者来源白细胞。受者淋巴细胞与相应供者淋巴细胞MLC阴性。,微嵌合（Microchimerism) 现象,77,双向排斥模式（ Two-way paradigm）与微嵌合,移植物中过路细胞刺激受者免疫细胞，产生HVGR。受者白细胞进入移植物，刺激供者免疫细胞,产生GVHR。药物（免疫抑制剂）的持续干预，同时抑制HVGR和GVHR。HVGR和GVHR最终达到一种无反应性的平衡状态，即供、 受者白细胞共存的微嵌合体状态。长期微嵌合状态可能形成对移植器官的耐受。,78,Transplant Tolerance Induction,Blockade of TCR recognition of allo-types For example,synthesized supermotif binds to allo-reactive TCR. TCR specific mAb Anti-TCR idiotype Ab,79,TCR,MHC,供者肽,T细胞,T细胞,APC,APC,人工合成的多肽,Synthesized supermotif blocks the TCR recognition of allo-MHC molecule.,80,Blockade of costimulatory Signals B7-CD28/CTLA-4;CD40-CD40L Gene expression interference AntibodySoluble ligand,Transplant Tolerance Induction,81,CTLA4-Ig and anti-CD40 ligand can both prevent and reverse acute allograft rejection, significantly prolonging the survival of major histocompatibility complex-mismatched renal allografts in primates without the need for chronic immunosuppression.,82,Nave Alloreactive T cell pool,Transplantation,MHC antigens,With Co-stimulation,Few apoptotic cells,Acute rejection,Memory T cell,Chronic Rejection,(Time),83,Nave Alloreactive T cell pool,Transplantation,MHC antigens,Without Co-stimulation,Many apoptotic cells,No rejection,Anergic and suppressor T cell,Tolerance,(Time),+CTLA4 Ig+anti-CD40L,Few effector T cell,84,85,86,不成熟DC细胞与微嵌合及移植耐受,不成熟DC细胞:低表