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苏州大学《免疫学》A卷苏州大学《免疫学》A卷参考答案共3页
一、名词解释
1.锚定残基与MHC结合成复合物的抗原肽往往带有两个或两个以上和MHC分子凹槽相结合的特定部位,称锚定位,该位置的氨基酸残基称为锚定残基anchor residueo
2.Negative selectionof T cells:T cellsthat reactstrongly toself-antigens onMHC areeliminated.Only thoseT cellsthat canreact toMHC,but donot bindstrongly toself-antigens emergeas matureT cellsfrom thethymus.
3.免疫细胞泛指所有参加免疫应答或与免疫应答有关的细胞及其前身,主要包括造血干细胞、淋巴细胞、单核/巨噬细胞及其他抗原递呈细胞、粒细胞、肥大细胞和红细胞等
4.抗体分子的类别转换B细胞所合成的1g重链的类别由一种如Igu转换为另一种如IgY或者Iga的过程类别转换不影响抗体分子的抗原特异性
5.DCs arerequired byT cellto enablethem torespond toantigens.DCs aremost importantantigen presentingcells knownso farand are the interfaceof innateand adoptiveimmunity.Functions:Antigen up-taking inperipheral sitesantigen presentationin lymphnodes.
6.ITAM免疫受体酪氨酸活化基序免疫细胞活化相关受体胞浆区所共有的以酪氨酸残基为基础的氨基酸序列基序,其特征为两个酪氨酸残基被大约13个其它氨基酸残基隔开,其中酪氨酸是蛋白激酶磷酸化位点,被磷酸化后能够与信号转导途径下游的信号分子结合,导致细胞的活化
7.MALT:The majority50%of lymphoidtissue in the humanbody islocated withinthe liningof themajor tracts,including respiratory,digestive andgenitourinary tracts.This isbecause these are themain sites of entryfor microbesinto thebody.These arecollectively calledthe mucosa-associated lymphoidtissues MALT.
8.GVHR:graft versushost reaction.If animmunocompromised hostis graftedwith foreignimmunocompetent lymphoidcells,the immunoreactiveT cells inthegraft recognizethe foreignantigens onthe hosttissue andcause theirdamage.GVHR occurswhen donor T cellsreact tohost antigenson APCswith sequentialactivation ofdonorT cells andmonocytes/macrophages causingtarget organdamage.
9.cytokines:Definition:Cytokines aresmall molecules,secreted bycellsinresponse toa stimulus.Function:As agroup,cytokines inducegrowth,differentiation,chemotaxis,activation and/or enhancedcytotoxity.They areused forstrengthening communicationsbetween cells.
10.Epitope:An epitopeis thespecific siteto whicha particularimmunoglobulin orTCR binds.
11.Idiotype:theseareunique antigenicdeterminants associatedwith anantigen bindingsitesofantibodies andaretheresult of the differentamino acidsequences whichderermine theirspecificities.
12.Autoimmunity:Autoimmunity isdefined asan acquiredimmune reactivityagainst selfantigens.This responseusually producesantoantibodies andantoreactive Tcells.
13.BCR complex:The BCRcomplex consistsoftheantigen receptor,Ig,in associationwith twoother polypeptides,Iga andTgp.Iga andIgp aresignaling moleculesfor theBCR andare alsorequired forassembly andexpression ofIg.
14.MHC:The majorhistocompatibility complex.Although moleculescoded forby theMHC wereoriginally identifiedbased ontheir rolein transplantrejection,they actuallyevolved topresent foreignantigens toTcells.Two classesClass Iand IIof MHCgenes,closed linkedon chromosome6in humans,code forhuman leukocyteantigens HLAwhich arethe moleculescritical toantigen presentation.
15.TA A:Tumor associatedantigens arealso foundon somenormal cells,which arethe quantitativedifferences inantigens associatedwith normalvs tumorcells,such asAFP,CEA.
二、问答题85=
401.简述T细胞识别抗原的双信号学说答2-signal theoryfor Tcell activation:A popularmodel toexplain therequirement of Tcellactivation isthe two-signal hypothesis
2.In thismodel,signal oneis derivedfrom theTCR aftertriggering byantigenic peptidepresented byMHC2and signaltwo isdelivered throughcostimulatory moleculesexpressed onthe surfaceofTcells,B cellsand APCs.2with2signals Tcell expressIL-2R alphachain andsecrete moreIL-
2.IL-2is Tcell growthfactor tostimulate Tcell proliferation.
22.试述内源性抗原和外源性抗原的提呈过程答内源性或者I类抗原递呈途径endogenous,or classI,antigen presentationpathway:内源性蛋白质分子在胞浆内被处理并通过MHC-I分子递呈于细胞表面的途径外源性或者II类抗原递呈途径exogenous,or classll,antigen presentingpathway:外源性蛋白质分子在吞噬溶酶体内被处理并通过MHC-II分子递呈于细胞表面的途径
3.试述超敏反应的概念、分型和发病机制答答免疫系统在发挥免疫效应的同时不可避免地给机体带来炎症性损伤,将这种现象称为超敏反应(2分)类型分型发病机制I型速发型超敏反应IgE吸附于肥大细胞或嗜碱粒细胞表面;过敏原与细胞表面的IgE结合;脱颗粒释放活性物质,作用于效应器官II型细胞毒型超敏反应抗体与细胞表面抗原结合,或抗原抗体复合物吸附于细胞表面;补体参与引起细胞溶解或损伤;巨噬细胞吞噬杀伤靶细胞;NK细胞通过ADCC效应杀伤靶细胞III型免疫复合物型超敏反应中等大小的IC沉积与血管壁基底膜或其他组织间隙;激活补体,吸引中性粒细胞,释放溶酶体酶,引起炎症反应;血小板凝聚,微血栓形成,导致局部缺血、淤血和出血IV型迟发型超敏反应抗原使T细胞致敏;致敏T细胞再次与抗原物质相遇直接杀伤靶细胞或产生各种淋巴因子,引起炎症反应(
1.5x4分)
4.补体活化的经典途径和终末途径,以及终末途径的杀伤机制答
(1)经典途径1)识别阶段抗原和抗体结合后,抗体发生构想改变,使FC段的补体结合部位暴露,补体C1与之结合并被激活,这一过程被称为补体激活的启动或识别(1分)2)活化阶段活化的CIS依次酶解C4,C2,形成具有酶活性的C3转化酶(1分),后者进一步酶解C3并行成C5转化酶(1分),最终引起相同的末端效应
(2)MAC的组装C5与C5转化酶的C3B结合,并被裂解成C5A和C5B依次于C6,C7结合所形成的C5B67复合物,插入浆膜中,进而与C8呈高亲和力结合,形成C5B678可于12-15个C9分子联接成C5B-9,即MAC(2分)MAC的效应机制MAC在胞膜上形成的小孔使得小的可溶性分子,离子以及水分子可以自由透过胞膜,但蛋白质之类的大分子却难以从胞浆中逸出,最终导致胞内渗透压降低,细胞溶解此外,末端补体成分插入胞膜,可能使致死量钙离子被动的向胞内弥散,并最终导致细胞死亡(3分)
5.抗体按结构可分为可变区和恒定区,叙述
①可变区和恒定区具体的结构
②可变区和恒定区各自介导的生物学效应
①两者的靠近N末端约110个AA序列组成可变区,其中包括抗原结合位点(高变区),高变区之间有框架区间隔(1分);靠近C末端的相对稳定的序列组成恒定区(1分)
②V区,特别是高变区发挥识别并特异性结合抗原的功能,进而产生免疫效应(2分)C区主要功能有三
1.激活补体;
2.调理作用结合细胞表面的Fc受体,从而促进吞噬细胞吞噬作用;
3.介导NK细胞的ADCC作用;
4.通过胎盘和粘膜(4分)。