苏州大学《免疫学》A卷

1、苏州大学免疫学 A 卷考试形式闭卷院系 _年级 _专业 _学号 _姓名 _成绩 _一、名词解释 (4 × 1560) （英文名词请用英文回答）1. 锚定残基：2. negative selection3. 免疫细胞：4. 抗体分子的类别转换5. DC6. 免疫受体酪氨酸活化基序列7. MALT8. GVHR9. cytokines10. Epitope11. Idiotype12. Autoimmunity13. BCR complex14. MHC15. TAA二、问答题（ 8× 540）1. 简述 T 细胞识别抗原的双信号学说。 ( 英文回答 )2. 试述内源性抗原和外

2、源性抗原的提呈过程。3. 试述超敏反应的概念、分型和发病机制。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。5. 抗体按结构可分为可变区和恒定区，叙述可变区和恒定区具体的结构可变区和恒定区各自介导的生物学效应。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 residue)。2Negative selection of T cells: T cells that react strongly to self-antigenson

3、 MHC are eliminated. Only those T cells that can react to MHC, but do not bindstrongly to self-antigens emerge as mature T cells from the thymus.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Ig 重链的类别由一种（如Ig ）转换为另一种（如 Ig 或者 Ig ）的过程。类别转换不影响抗体分子的抗原特异

4、性。5. DCs are required by T cell to enable them to respond to antigens. DCs are mostimportantantigenpresentingcellsknown so farand are the interfaceof innateandadoptive immunity. Functions: Antigen up-taking in peripheral sites & antigenpresentation in lymph nodes.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

5、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 majority (50%) of lymphoid tissue in the human body is located withinthe liningof the major tracts,includingrespiratory,digestiveand genitourinarytracts.This is because these are the main

6、 sitesof entryformicrobesintothe body.These are collectively called the mucosa-associated lymphoid tissues (MALT).8. GVHR:graft versus host reaction. If an immunocompromised host is grafted with foreign immunocompetent lymphoid cells, the immunoreactive T cells in the graftrecognize the foreign anti

7、gens on the host tissue and cause their damage. GVHRoccurswhen donor T cellsreactto host antigenson APCs with sequentialactivationof donorT cells and monocytes / macrophages causing target organ damage.9.cytokines:Definition: Cytokines are small molecules, secreted by cells inresponsetoastimulus.Fun

8、ction:Asagroup,cytokinesinducegrowth,differentiation, chemotaxis, activation and/orenhanced cytotoxity. They areusedfor strengthening communications between cells.10. Epitope: An epitope is the specific site to which a particular immunoglobulin or TCR binds .11.Idiotype:these are unique antigenic de

9、terminants associated with an antigenbindingsitesofantibodiesand arethe resultof the differentamino acidsequenceswhich derermine their specificities.12.Autoimmunity:Autoimmunityisdefinedas an acquiredimmune reactivityagainstself antigens. This response usually produces antoantibodies and antoreactiv

10、e Tcells.13.BCRcomplex:The BCRcomplexconsistsof theantigen receptor,Ig, in associationwith two other polypeptides, Ig and Ig . Ig and Ig are signaling moleculesfor the BCR and are also required for assembly and expression of Ig.14.MHC: The major histocompatibilitycomplex.Althoughmoleculescoded forby

11、 theMHC were originally identified based on their role in transplant rejection, theyactually evolved to present foreign antigens to T cells. Two classes (Class I andII)ofMHCgenes,closed linkedon chromosome 6 inhumans, code forhuman leukocyteantigens (HLA) which are the molecules critical to antigen

12、presentation.15.TAA: Tumor associated antigens are also found on some normal cells, which arethequantitativedifferencesinantigensassociatedwithnormalvs tumor cells,suchas AFP, CEA.二、问答题（8× 5 40）1. 简述 T 细胞识别抗原的双信号学说。答: 2-signal theory for T cell activation:A popular model to explain the requirem

13、ent of T cellactivation is the two-signal hypothesis(2). In this model, signal one is derived from the TCRafter triggering by antigenic peptide presented by MHC(2) and signal two is delivered throughcostimulatorymoleculesexpressed on the surfaceof T cells,B cells andAPCs.(2) with2 signalsT cellexpre

14、ssIL-2Ralpha chainand secretemore IL-2.IL-2is T cellgrowthfactorto stimulateT cell proliferation.(2)2. 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 class I, 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 classII,antigenpresentingpathw

15、ay):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（4 分）（4 分）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

16、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（ 4 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 C1S 依次酶解 C4， C2，形成具有酶活性的C3 转化酶（ 1

17、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）。