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 X 15= 60)(英文名词请用英文回答) 1. 锚定残基： 2. negative selection 3. 免疫细胞： 4. 抗体分子的类别转换 5. DC 6. 免疫受体酪氨酸活化基序列 7. MALT 8. GVHR 9. cytokines 10. Epitope 11. Idiotype 12. Autoimmunity 13. BCR complex 14. MHC 15. TAA 二、问答题(8X 5 = 40) 1. 简述 T 细胞识别抗原的双信号学说。(英文

2、回答) 2. 试述内源性抗原和外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 、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) 。 2. Negative selection of T cells: T cells th

3、at react strongly to self-antigens on MHC are eliminated. Only those T cells that can react to MHC, but do not bind strongly 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 lg 重链的类别

4、由一种(如 lg 卩)转换为另一 种(如 lg 丫或者 lg a)的过程。类别转换不影响抗体分子的抗原特异性。 5. DCs are required by T cell to enable them to respond to antigens. DCs are most important antigen presenting cells known so far and are the interface of innate and adoptive immunity. Functions: Antigen up-taking in peripheral sites & anti

5、gen presentation in lymph nodes. 6. lTAM： 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 majority (50%) of lymphoid tissue in the human body is located within the lining of the major tracts, including resp

6、iratory, digestive and genitourinary tracts. This is because these are the main sites of entry for microbes into the body. These are collectively called the mucosa-associated lymphoid tissues (MALT). 8. GVHR:graft versus host reaction. lf an immunocompromised host is grafted with foreign immunocompe

7、tent lymphoid cells, the immunoreactive T cells in the graft recognize the foreign antigens on the host tissue and cause their damage. GVHRoccurs when donor T cells react to host antigens on APCswith sequential activation of donor T cells and monocytes / macrophages causing target organ damage. 9. c

8、ytokines: Definition: Cytokines are small molecules, secreted by cells in response to a stimulus. Function: As a group, cytokines induce growth, differentiation, chemotaxis, activation and/or enhanced cytotoxity. They are used for strengthening communications between cells. 10. Epitope: An epitope i

9、s the specific site to which a particular immunoglobulin or TCR binds . 11. Idiotype: these are unique antigenic determinants associated with an antigen binding sites of antibodies and are the result of the different amino acid sequences which derermine their specificities. 12. Autoimmunity: Autoimm

10、unity is defined as an acquired immune reactivity against self antigens. This response usually produces antoantibodies and antoreactive T cells. 13. BCRcomplex: The BCRcomplex consists of the antigen receptor, Ig, in association with two other polypeptides, lg a and lg 3 . Ig a and Ig 3 are signalin

11、g molecules for the BCR and are also required for assembly and expression of Ig. 14. MHC: Th e major histocompatibility complex. Although molecules coded for by the MHC were originally identified based on their role in transplant rejection, they actually evolved to present foreign antigens to T cell

12、s. Two classes (Class I and II) of MHCgenes, closed linked on chromosome 6 in humans, code for human leukocyte antigens (HLA) which are the molecules critical to antigen presentation. 15. TAA: Tumor associated antigens are also found on some normal cells, which are the quantitative differences in an

13、tigens associated with normal vs tumor cells, such as AFP, CEA. 二、问答题(8X 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 requirement of T cell activation is the two-signal hypothesis(2). In this model, signal one is derived from the TCR after trig

14、gering by antigenic peptide presented by MHC(2) and signal two is delivered through costimulatory molecules expressed on the surface of T cells, B cells and APCs.(2) with 2 signals T cell express IL-2R alpha chain and secrete more IL-2. IL-2 is T cell growth factor to stimulate T cell proliferation.

15、(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 (en doge nous, or class I, an tigen prese ntation pathway):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 (exoge no us, or classII, an tige n prese nting pathway): 答：2-signal theory for T cell activation: A popular model to explain the requi

16、rement of T cell (4 分)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) 帅源性抗豐的加工及提呈过程 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, 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

17、；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 （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

18、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 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 C5B67&可于 12-15 个 C9 分子联接成 C5B-9，即 MAC（ 2 分）。 MAC 勺效应机制：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， 将这种现象称 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