IMMUNOSENESCENCE AND ALTERED GERMINAL CENTER RESPONSE

免疫衰老和生发中心反应改变

• 批准号: 6135462
• 负责人: Biao Zheng
• 金额: $ 22.17万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6135462
• 关键词: B lymphocyte; CD95 molecule; T lymphocyte; affinity labeling; age difference; antigen receptors; apoptosis; autoimmunity; cell population study; crosslink; developmental immunology; dissection; flow cytometry; gene rearrangement; gene targeting; genetically modified animals; immune tolerance /unresponsiveness; immunoglobulin genes; immunosenescence; laboratory mouse; lectin; lymphocyte proliferation; receptor expression; recombinase; spleen

The relationship between alteration of germinal center response and immune dysfunction in aging will be studied. In secondary lymphoid organs, germinal centers are sites of post-rearrangement B-cell repertoire modification by V(D)J hypermutation, receptor editing and affinity-driven clonal selection; germinal centers are also necessary for generation of the B-cell memory compartment. Furthermore, our recent work suggests that the germinal center reaction may recapitulate some aspects of primary lymphogenesis and plays a role in the induction and maintenance of self-tolerance in the periphery through selective apoptosis. With in situ and ex vivo approaches, I will test the hypothesis that altered germinal center response plays an important role in immunosenescence, including diminished immune response and heightened autoimmunity. Enzyme- and fluorochrome-labeled antibodies and lectins will be used to characterize and follow the responding lymphocyte populations, especially in reference to germinal centers. BrdUrd- and Tdt-labelling as well as antibodies to apoptosis-associated proteins will be used to study cell proliferation and programmed cell death. Cross-linking reagents for antigen-receptors, steroids and inhibitors for apoptosis will be applied to test the sensitivity and specificity of lymphocyte subpopulations to apoptotic signals. Microdissection of small groups or individual cells from histologic sections and FACS sorting of cell populations will be used in conjunction with various PCR amplification of V(D)J rearrangements, ds RSS breaks, and other gene segments of interest to study the somatic genetics of lymphocytes during the course of aging. These approaches will make possible to systemically study the effect of aging on germinal center response and its consequence.

将研究生发中心反应的改变与衰老中免疫功能障碍之间的关系。 在继发性淋巴器官中，生发中心是通过V（d）J HyperMot，受体编辑和亲和力驱动的克隆选择的续率B细胞曲目修饰的部位；生发中心也是生成B细胞记忆室的必要条件。 此外，我们最近的工作表明，生发中心反应可能会概括原发性淋巴发生的某些方面，并通过选择性凋亡在外围的诱导和维持中发挥作用。使用原位和离体方法，我将检验以下假设，该假设改变了生发中心反应在免疫衰老中起重要作用，包括免疫反应降低和自身免疫的增强。 酶和荧光素标记的抗体和凝集素将用于表征和遵循反应的淋巴细胞种群，尤其是在引用生发中心。 BRDURD和TDT标签以及与凋亡相关蛋白的抗体将用于研究细胞增殖和程序性细胞死亡。 抗原受体，类固醇和凋亡抑制剂的交联试剂将用于测试淋巴细胞亚群对凋亡信号的敏感性和特异性。从组织学切片和细胞群体中的小组或单个细胞进行显微解剖，将与V（d）J重新排列，DS RSS断裂和其他感兴趣的其他基因段一起使用各种PCR扩增，以研究在衰变过程中淋巴细胞的体细胞遗传学。 这些方法将有可能从系统地研究衰老对生发中心反应及其后果的影响。