IMMUNOSENESCENCE AND ALTERED GERMINAL CENTER RESPONSE

免疫衰老和生发中心反应改变

• 批准号: 6706691
• 负责人: Biao Zheng
• 金额: $ 3.94万
• 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/6706691
• 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.

本文将探讨老年中枢反应的改变与免疫功能障碍的关系。 在次级淋巴器官中，生发中心是通过V（D）J超突变、受体编辑和亲和力驱动的克隆选择进行重排后B细胞库修饰的位点;生发中心也是B细胞记忆区室产生所必需的。 此外，我们最近的工作表明，生发中心的反应可能重演的一些方面的初级淋巴细胞生成，并发挥了作用，在诱导和维持自身耐受性的外周，通过选择性凋亡。通过原位和离体方法，我将检验这一假设，即改变的生发中心反应在免疫衰老中起着重要作用，包括免疫反应减弱和自身免疫增强。 酶和荧光染料标记的抗体和凝集素将用于表征和跟踪响应的淋巴细胞群，特别是在参考生发中心。 BrdUrd-和Tdt-标记，以及抗体的骨化相关蛋白将用于研究细胞增殖和程序性细胞死亡。 抗原受体的交联剂、类固醇和细胞凋亡抑制剂将用于测试淋巴细胞亚群对细胞凋亡信号的敏感性和特异性。来自组织切片的小群或单个细胞的显微解剖和细胞群的流式细胞仪分选将与V（D）J重排、ds RSS断裂和其他感兴趣的基因片段的各种PCR扩增结合使用，以研究淋巴细胞的体细胞遗传学在衰老过程中。 这些方法将有可能系统地研究衰老对老年中枢反应及其后果的影响。