免疫生物学作业20130110

1 Recognition of bacteria by mannose binding lectin can lead to their destruction by the same mechanisms as recognition by antibody Explain why this is so and describe additional common features between these pathways of pathogen recognition 2 The innate immune system uses two different strategies to identify pathogens recognition of nonself and recognition of self a Give examples of each and discuss how each example contributes to the ability of the organism to protect itself from infection b What are the disadvantages of these different strategies recognitionrecognition ofof nonselfnonself 溶菌酶 抗菌肽 吞噬型受体 TLR NOD RIG NK 细胞的活化性受体 recognitionrecognition ofof selfself 1 NK 细胞抑制性受体 2 补体调控蛋白 Disadvantage 1 局限性 2 交叉反应性 3 本身突变 3 Mutation produced during affinity maturation are initially generated randomly by the action of AID and yet eventually amino acid changes to the antibody are clustered to the three CDRs in the V regions a What is the relationship between the location of the CDRs and the V D J junctions b How might randomly generated mutations in DNA lead to an enrichment of mutations that are restricted to the CDRs after an immune response a CDRs 区和 V D J junctions 之间的关系 b 免疫应答后 DNA 随机产生的突变怎样富集限制在 CDRs F R 保守 CDR 多变 识别 结合抗原 抗原识别 V 区 CDR 区 导入点突变 提高亲和力 体细胞高频突 变 4 MHC class and class molecules are structurally and functionally homologous yet have dissimilar pathways of assembly and delivery to the cell surface a Describe how these differences in assembly and delivery are integrated with the different functions of class and class molecules b How do these functions related to the source from which class I or class II MHC receive peptides c Give that the processes of cross presentation and autophagy can redirect antigens from various sources for processing by alternative pathways how do these processes alter your answer to b a B MHC I and MHC II 功能与 MHC I 或 MHC II 接受的抗原肽的来源关系 1 胞浆病原体 MHC I 2 小泡病原体 细胞外病原体毒素 MHC II c cross presentation 外源性加工途径变为内源性加工途径 可以活化 CD8 细 胞 增强对病原体的清除 Autophagy 内源性加工途径变为外内源性加工途径 可以活化 CD4 细胞 加强 CD8 MAC 功能 5 Many of the proteins encoded within the MHC exist in the population in multiple forms or allelic variants a What genetic events give rise to this variation and what are its functional consequences b In some cases particular combinations of alleles of the different MHC genes are found to be present at a far higher frequency than chance would predict What are the possible mechanisms that might explain this finding a MHC 分子高度多态性 环境压力特别是病原压力 b 在进化过程中 环境压力诱导可操纵 MHC 分子的分布 6 B cell development in the bone marrow shares many features with T cell development in the thymus a What are the two major goals of lymphocyte development b Discuss the ordered steps of receptor rearrangement in B and T cells drawing the parallels between the two cell types c What is the function of the pre B cell receptor and the pre T cell receptor d Why do T cells develop in the thymus and B cells develop in the bone marrow C 等位基因排斥 重 链重排 d T 细胞在胸腺发育 1 双识别 2 Notch 信号 3 Aire 基因 B 细胞在骨髓发育 黏附分子 细胞因子 趋化因子 7 Lymphocyte development is notable for huge cell losses at several steps a What are the major reasons that lymphocytes die without progressing beyond the pre T cell or pre B cell stage b What is the major reason that lymphocytes die after reaching the immature stage of expressing a complete TCR or BCR a 在 pre T cell or pre B cell 阶段之后 淋巴细胞没有继续发育而死亡的主 要原因是 无效性重排 b 淋巴细胞在发育为完全表达 TCR or BCR 的未成熟阶段死亡的主要原因是 阴性选择 T B 和阳性选择 T 8 Discuss the process of positive selection of T cells in the thymus a Where does it take place b What are the ligands c When at what stage during T cell development does positive selection occur d Describe how the choice between expression of the co receptor CD4 or CD8 occurs and identify any known regulators of this process 略 9 Consider the claim T cell effector functions are primarily mediated by secreted products a To what extent is this statement true for CD4 cells and for CD8 T cells b Describe the roles of T cell membrane bound effector molecules in activating macrophages a b 表达 CD40L 分泌 IFN 表达 FasL LT 10 Describe the requirements for the activation of naive B cells by a thymus dependent antigen By what mechanisms do T cells provide