病毒感染与自身免疫病课件

1、病毒感染与自身免疫病病毒感染与自身免疫病 Virus Infections and autoimmunity Exogenous viruses: EBV Molecular mechanism for autoimmunityEnogenous viruses : HERVAutoimmune disease: A role for new antiviral therapies?Outline Outline Virus Infections and autoimmunity (Background)自身免疫是机体失去对自身抗原的免疫耐受自身免疫病因与发病机制十分复杂: 遗传背景，但环境因

2、素和生活方式等的也有重要作用。研究表明病毒和细菌等感染与自身免疫病的发生、发展密切关系。一些病毒感染可导致机体失去对自身抗原免疫耐受，因而诱发、促进或加重自身免疫病。已证明某些病毒感染与一些自身免疫病密切相关，并发现病毒与宿主细胞的某些基因或其蛋白分子之间存在着结构类似性，因而可发生交叉免疫反应性。这种分子模拟假说获动物实验的支持。 Virus Infections and autoim少数T细胞克隆逃 避阴性选择 进入外周识别自身抗原 通过激活诱导细胞死亡（AICD) (FasL-Fas-凋亡）部分T细胞克隆 逃避AICD识别自身抗原自身免疫病(AID)T细胞发育过程自身耐受形成及逃避机制少

3、数T细胞克隆逃识别自身抗原 通过激活诱导部分T细胞克B细胞发育过程自身耐受形成及逃避机制 克隆清除 结合 克隆无能 克隆忽视 不结合 克隆发育成熟激活自身免疫病 自身免疫病激活B细胞骨髓细胞表面抗原B细胞发育过程自身耐受形成及逃避机制 HostMHCLoss of ToleranceImmune system defectsSusceptibility GenesEndogenous VirusesAutoimmune diseaseEnvironment and autoimmunityChemical substancesMicrobial AgentsdrugsUVB lightVacc

4、inestyphoid, influenza, meningococcal, tetanus toxoid, measles, mumps, and rubellaDiet/NutritionHostEnvironment and autoimmuni新西兰小鼠(NzB)自发产生抗DNA抗红细胞抗体溶血性贫血狼疮性肾炎自然发生新西兰小鼠(NZW)不发生系统性红斑狼疮(SLE)NZB X NZW(F1) 杂交小鼠抗DNA和其他核抗体与人类SLE类似感染病毒感染病毒自身抗体效价更高自身免疫病的发生更早发生自身免疫病These observations lend further support th

5、at both genetic and environmental factors play a role in autoimmune disease.新西兰小鼠(NzB)自发产生抗DNA溶血性贫血自然发生新西兰病毒感染与自身免疫病课件Exogenous virusesExogenous microbial agents, such as bacteria or viruses, interact with and sometimes might override the human immune system to cause infectious diseases, cancers and

6、 autoimmunity.Exogenous virusesExogenous micExogenous viral agents have also been implicated as potential triggers or pathogenic agents of autoimmune conditions. Viruses which have been linked to the pathogenesis of SLE include EpsteinBarr Virus (EBV) Cytomegalovirus (CMV), parvovirus (细小) B19 Human

7、 Papilloma Virus (HPV), Human Herpes Virus (HHV6), HHV7, HHV8, Dengue virus HIV human T cell lymphotropic virus (HTLV,人类嗜T细胞病毒 )Exogenous viral agents have alEBV as a potential viral agent in SLEIn SLE, EBV has been highlighted as a potential pathogenic agent through serological studies of patients

8、that have shown antibodies to early antigens, capsid and latent membrane proteins in much higher frequency as compared to controlsin pediatric SLE, 99% of patients are antiEBV Ab+ compared to 70% of controlsIn people with SLE, the number of EBV infected B cells is elevated 10 to 100 times over the l

9、evels in controls, and the amount of free virus in serum is also elevated.molecular analysis of complementary EBV transcripts appears to substantiate these observationIncreased virus levels are associated with disease flares LMP1 mRNA is the most frequently detected latent EBV product in the blood o

10、f SLE patientsa metaanalysis of serological studies revealed that antibodies to capsid and early antigen proteins were particularly prominent.EBV is recognized as a strong polyclonal B cell activator and therefore could stimulate a substantial number of potentially autoreactive B cells.EBV as a pote

11、ntial viral agentEBV 结构和蛋白（Epstein-Barr virus，EBV）Epstein和Barr：1964年首次成功地在Burkitt非洲儿童淋巴瘤细胞中发现靶细胞： B细胞、鼻咽上皮细胞、胃上皮感染类型： 潜伏感染 核抗原（EBNA），潜伏膜蛋白（LMP） 增殖感染 早期蛋白（EA）， 病毒衣壳抗原（VCA） 膜抗原（MA）受体：CD21分子EBV 结构和蛋白（Epstein-Barr virus，E增殖性感染表达的抗原 当EBV进入宿主细胞后，首先表达反式激活蛋白ZERBA，进而激活EBV早期基因，产生增殖性感染。 EBV早期抗原(early antigen,

12、EA) 增殖早期诱导的非结构蛋白，分为 EAR存在于细胞浆中 EAD存在于细胞浆和细胞核内，并具有EBV特异的DNA多聚酶活性。 EA表示EBV增殖活跃，是感染细胞进入溶解性周期的标志。 非洲儿童恶性淋巴瘤患者抗EAR抗体阳性，鼻咽癌患者抗EAD抗体阳性。EBV衣壳抗原(viral capsid antigen, VCA) : 病毒增殖晚期合成的结构蛋白，存在于细胞浆和细胞核内。 VCA: 与病毒DNA组成EBV的核衣壳，在核膜出芽时获得包膜装配成完整病毒体。 VCAIgM: 出现早，消失快，VCAIgG:出现晚，持续时间长。EBV膜抗原(membrance antigen, MA) 存在于细

13、胞表面，为包膜糖蛋白，其中 糖蛋白gp320/220能诱导产生中和抗体。 MAIgM: 用于早期诊断，MAIgG: 可体内持续存在。增殖性感染表达的抗原 当EBV进入宿主细胞后，首先表潜伏性感染表达的抗原 EBV在记忆B细胞及某些上皮细胞中可表现为潜伏感染，仅部分表达基因发生转录， 选择性表达EBV潜伏感染期蛋白。 EBV核抗原（EB nuclear antigen, EBNA）: DNA结合蛋白，所有EBV感染 和转化的B细胞核内均可检出该抗原。 (EBNA1, 2, 3A, 3B, and 3C) EBNA1: 与EBV基因组以环状附加体(episome)形式持续存在，对细 胞处理和抗原提

14、呈功能具有抑制作用，从而逃避宿主细胞的 CTL杀伤作用，因此与维持EBV基因组在感染细胞内潜伏有关； EBNA2和EBNA3为转录因子: 可调控多种病毒蛋白和宿主细胞蛋白的表 达，与诱导B细胞转化有关。潜伏感染膜蛋白(latent membrance protein, LMP) : 存在于潜伏感染B细胞表面，有LMP1和LMP2 (LMP2A,LMP2B)两种。 LMP1: 功能类似活化的生长因子受体，能与细胞抑癌蛋白（肿瘤坏死因子受体相关 因子，TRAF）相互作用，抑制细胞凋亡，诱导B细胞转化，是一种致癌蛋白； LMP2: 细胞酪氨酸激酶的底物，具有阻止潜伏病毒激活的作用。潜伏性感染表达的抗

15、原 EBV在记忆B细胞及某些上皮细Gp350-CD21BMRF2-1整合素gp110-?Gp350-CD21BMRF2-1整合素gp110-?EBV specific CD8+ Tcells are enriched in or near the diseased organs of patients with RA and MS .膜抗原（MA）Bystander Activation（旁路激活）MSRV 体内外均可激活Tcells 并诱导产生 cytokines.EBV as a potential viral agent in SLEEBV 诱导内源性逆转录病毒产生 HERVK18HER

16、VK18编码超抗原激活 T细胞HERV数量虽多，但大部分由于突变、缺失等的积累，已经没有编码能力。in serum is also elevated.domains, termed CTAR1, CTAR2 and CTAR3, which recruit TNFR-associated signalling adapter proteinsautoimmune disease.抗DNA和其他核抗体与人类SLE类似Serum antibodies from SLE patients have also demonstrated to an envelope derived peptide of

17、 HERV K10typhoid, influenza, meningococcal, tetanus toxoid, measles, mumps, and rubellaERV3，HERVE 41HERV抗体在睾丸肿瘤、乳癌和黑素瘤中很常见。(HTLV,人类嗜T细胞病毒 )molecular analysis of complementary EBV transcripts appears to substantiate these observation结合 克隆无能Immunological Mechanisms for AutoimmunityMolecular MimicryBys

18、tander Activation and Epitope Spreading Polyspecific Bcell Activation Accumulation of EBVspecific CD8+ Tcells in Sites of Inflammation Transactivation of Human Endogenous Retroviruses （反式激活）EBV specific CD8+ Tcells are eMolecular mimicrySequence or structural similarities between microbial and selfa

19、ntigens are believed to cause crossreactivity of Tcells, Bcells and antibodies Molecular mimicrySequence or sEBNA1In SLE, autoantibodies against epitopes on SmBB and SmD have been shown to crossreact with different domains of EBNA1 EBNA1 motif PPPGRRP (aa 398404) Rabbits immunized lupuslike autoimmu

20、ne disease EBNA1 full length protein mice immunized antidsDNA and antiSm antibodiesRo (aa 169180) autoantibodies SLE EBNA1 (aa 5872) cross-reactionEBNA1In SLE, autoantibodies ag李玲玲，朱珊丽，李文姝，薛向阳，张丽芳* EBV核蛋白-1B细胞表位的预测及其同源性分析 生物医学工程学杂志 2011，28（2）：371-375李玲玲，朱珊丽，李文姝，薛向阳，张丽芳* EBV核蛋白-1LMP1LMP1 expression h

21、as been implicated in making important contributions to a variety of human malignancies, as well as to autoimmune diseases.LMP1 alters Bcell biology and the molecular mechanisms by which it exerts these effects by LMP1mediated signaling pathwaysLMP1LMP1 expression has been iFig. 1. Activation of cel

22、l signalling pathways by LMP1. The carboxyl terminus of LMP1 contains three signalling domains, termed CTAR1, CTAR2 and CTAR3, which recruit TNFR-associated signalling adapter proteins (TRAF, TRADD, RIP), BS69 and Janus kinase (JAK)-3 proteins. These activate the NF-B, JNK/SAPK, PI3-K/Akt, ERK-MAPK,

23、 PLC/PKC and JAK/STAT signalling pathways, which collectively induce the expression of numerous downstream effectors that impact on a variety of cellular processes such as proliferation, survival, motility and invasion. 187-386: 200个氨基酸残基为C端胞浆区，含活性区域1-3（CTAR1，2，3） IFNIL-6IL-10IFN- play an important

24、rolein SLE pathogenesis. (development of the inflammatory)in theFig. 1. Activation of cell sigBystander Activation（旁路激活）Bystander activation lymphocytes are stimulated by cytokines or superantigens, or antigendependent in the setting of tissue destruction and presentation of selfantigens by APC to a

25、utoreactive T or Bcells抗微生物 抗体（T细胞表位不同，无Th活化信号）Bystander Activation（旁路激活）Byst抗微生物 抗体抗微生物Epitope Spreading（表位扩展）抗原刺激免疫系统，首先针对免疫优势表位产生免疫应答，如果抗原没有及时清除，免疫应答持续时，机体可相继针对隐蔽表位产生应答表位扩展。Epitope Spreading（表位扩展）抗原刺激免疫系Polyspecific Bcell Activation（非特异性激活）Polyspecific Bcell Activation（Accumulation of EBVspecific

26、 CD8+ Tcells in Sites of InflammationEBV specific CD8+ Tcells are enriched in or near the diseased organs of patients with RA and MS . EBVspecific CD8+ Tcells have also been reported to accumulate in synovial fluid (滑液)from patients with psoriatic arthritis, osteoarthritis and Reiters syndrome局部炎症部位

27、EBV特异性CTL细胞的集聚，加剧了局部的炎症反应Accumulation of EBVspecific CDTransactivation of Human Endogenous Retroviruses EBV 诱导内源性逆转录病毒产生 HERVK18HERVK18编码超抗原激活 T细胞 HERVK18表达产物在RA的外周血和关节液中出现 ，但SLE尚未报道。 已经证明EBV 在体外可激活HERVW（MS相关逆转录病毒（MSRV），在MS患者的星形胶质细胞，B细胞和单核细胞中存在MSRVMSRV 体内外均可激活Tcells 并诱导产生 cytokines. Transactivation

28、of Human EndogEnogenous viruses : Human Endogenous Retroviruses （HERV） HERV是几百万年前整合到人类基因组中，并以孟德尔方式遗传至今的逆转录病毒的残余物，约占了人类基因组DNA的8HERV可以通过转座作用而增加其在基因组中的拷贝数，因此有些家族的成员数达上千个，现已发现的HERV家族至少有31个。HERV数量虽多，但大部分由于突变、缺失等的积累，已经没有编码能力。HERV各家族基因结构基本相同，但许多功能都不明确，过去大多数研究人员将内源性逆转录病毒视为垃圾DNA。Enogenous viruses : Human End

29、HERV 编码的超抗原、HERV 病毒颗粒及 B细胞表达的蛋白 激活和巨噬细胞1997年，发现多发性硬化症(MS)患者细胞培养过程中产生了EAR存在于细胞浆中Environment and autoimmunityBystander Activation and Epitope SpreadingLMP1 alters Bcell biology and the molecular mechanisms by which it exerts these effects by LMP1mediated signaling pathwaysEAD存在于细胞浆和细胞核内，并具有EBV特异的DNA多聚

30、酶活性。B细胞发育过程自身耐受形成及逃避机制EBNA2和EBNA3为转录因子: 可调控多种病毒蛋白和宿主细胞蛋白的表和转化的B细胞核内均可检出该抗原。Cytomegalovirus (CMV),HERVK18表达产物在RA的外周血和关节液中出现 ，但SLE尚未报道。EBNA2和EBNA3为转录因子: 可调控多种病毒蛋白和宿主细胞蛋白的表28kD nuclear autoantigen (p28) HRES1/p28HERV与系统性红斑狼疮的关系EBNA1 motif PPPGRRP (aa 398404)Schematic representation of HERV-K10.具有高度的病毒特

31、异性和有效性即可针对病毒复制又可针对病毒的长期持续感染。Class II HERVs:(HTLV,人类嗜T细胞病毒 )Class III :Human Endogenous Retroviruses （HERV）随着研究的深人，人们发现少部分HERV保留了产生逆转录病毒产物和病毒颗粒的能力HERV与人类的进化关系密切，是哺乳动物生殖所必需的，并且影响哺乳动物胎盘发育，是妊娠所不可或缺的基因。同时和胎盘共同构建了一个防止微生物感染胎盘的屏障。HERV还参与人体多种自身免疫性疾病和肿瘤的发生和发展过程。 HERV抗体在睾丸肿瘤、乳癌和黑素瘤中很常见。HERV 编码的超抗原、HERV 病毒颗粒及 B

32、细胞表达的蛋几百万年前，HERV感染人类的生殖细胞，从而成为宿主遗传基因组的一部分。遗传给宿主的子孙后代。整合在人类基因组中的内源性逆转录病毒无法从宿主的DNA上转录。几百万年前，HERV感染人类的生殖细胞，从而成为宿主遗传基因病毒感染与自身免疫病课件 Schematic representation of HERV-K10. Insert: electron micrograph (magnification: 15,000) of HERV-K particles budding from a teratocarcinoma（畸胎瘤） cell line TERA-1. Schematic

33、 repreHERVsClass I HERVs: HRES1， (HERVR) ERV3 HERVE 41Class II HERVs: HERVK10， HERVK18Class III : HERVsClass I HERVs:HRES1two Gagrelated products : 28kD nuclear autoantigen (p28) HRES1/p28 24kD small GTPase (termed HRES1/Rab4)higher titres of autoantibodies to HRES1/p28 nuclear protein or synthetic

34、peptides in patients with SLEMolecular mimicry may be responsible in generating crossreactive HRES1/p28 and the 70kD spliceome protein U1 snRNP.In lupus patientsCD4 + T cells appear to overexpress HRES1/Rab4， which regulates the CD4.Thus, Gagrelated products could play a significant role in modulati

35、ng B and T cell reactivity in SLEHRES1two Gagrelated products :Figure 3 (a) Molecular models of a homologous epitopes located on SmD1 and HRES-1. (b) Amino acid sequence homology between HRES-1 gag and SLE autoantigens.Figure 3 (a) Molecular models ERV3，HERVE 41ERV3 Env and several SLE autoantigens,

36、 RibosomalP,Ro/SSAribo nuclear protein and Beta2glycoprotein共同抗原Beta2glycoprotein is associated with antiphospholipid syndrome（抗磷脂综合征）, whilst RibosomalP （核糖体磷脂）antibodies are strongly associated with SLE, as demonstrated in a mouse model.Peripheral blood mononuclear cells derived from SLE patients

37、generate mRNA gag transcripts of HERVE 41ERV3，HERVE 41ERV3 Env and seveHERV K10Serum antibodies from SLE patients have also demonstrated to an envelope derived peptide of HERV K10Herpes viruses such as EBV and CMV have been shown to influence HERVK10 activity and upregulate HERV transcriptionEBV gen

38、e products, EBNA1, Latent Membrane Protein (LMP1) and LMP2A, significantly enhance HERVK10 transcripts.HERV K10Serum antibodies from HERV与系统性红斑狼疮的关系在系统性红斑狼疮患者的器官和血清中发现了HERV成分的抗原及相应 的抗体， 电镜观察系统性红斑狼疮患者的组织，发现了逆转录病毒颗粒HRES1, ERV3, HERVE 41, HERVK10 and HERVK18 have also been implicated in SLE.在体外实验中HERV逆

39、转录病毒成分可以诱导出系统性红斑狼疮样的免疫异常合成的HERV E 41来源的多肽P15E (env序列编码的跨膜蛋白)，能 够诱导许多免疫异常，如CD4+ T细胞的活化和失能，细胞因子的产生(如IL6、IL16)和细胞因子相关的多克隆B细胞活化。近来有研究者报道，在系统性红斑狼疮患者中HERV E 41序列比正 常对照组转录明显增加，大约有50 的患者血清中发现能与其转录产物结合的抗体，而对照组是零 。HERV与系统性红斑狼疮的关系在系统性红斑狼疮患者的器官和血HERV与类风湿性关节炎的关系与健康对照人群或者骨关节炎患者相比，类风湿性关节炎患者的HERVK10 mRNA表达增加，提示HERV

40、K10可能与这种自身免疫性疾病的致病性有关研究结果显示，68 的类风湿性关节炎患者的外周血中单核细胞中HERVK10 mRNA表达水平增加，骨关节炎患者为l7 ，对照组为185。在类风湿性关节炎患者中HERV增加可能与宿主蛋白的分子模拟相关，或由环境因素触发激活了HERVs。含活化HERV的宿主细胞移行到滑膜并产生促炎细胞因子，诱导RA疾病的发生。HERV与类风湿性关节炎的关系与健康对照人群或者骨关节炎患者Ro (aa 169180) autoantibodies SLE抗DNA和其他核抗体与人类SLE类似在类风湿性关节炎患者中HERV增加可能与宿主蛋白的分子模拟相关，或由环境因素触发激活了H

41、ERVs。Class I HERVs:EBNA1 motif PPPGRRP (aa 398404)in pediatric SLE, 99% of patients are antiEBV Ab+ compared to 70% of controlsEpsteinBarr Virus (EBV)EpsteinBarr Virus (EBV)BMRF2-1整合素Immune system defectsRetroviral integrase inhibitors as a novel form of antiviral therapy for autoimmune disease28kD

42、nuclear autoantigen (p28) HRES1/p28局部炎症部位EBV特异性CTL细胞的集聚，加剧了局部的炎症反应用免疫组化法对HERVW家族检测在健康人脑的神经细胞中有HERVW 的Gag蛋白的生理表达，而在MS患者的脱髓鞘脑白质的轴突结构中Gag蛋白有显著的积累，在病理组织的内皮细胞中也观察到了Gag蛋白的高表达。HERV 编码的超抗原、HERV 病毒颗粒及 B细胞表达的蛋白 激活和巨噬细胞(FasL-Fas-凋亡）EAD存在于细胞浆和细胞核内，并具有EBV特异的DNA多聚酶活性。in pediatric SLE, 99% of patients are antiEBV Ab+ compared to 70% of controlsHERV与多发性硬化症的关系1997年，发现多发性硬化症(MS)患