THYMUS INVOLUTION AND RECENT THYMIC EMIGRANTS

胸腺退化和最近的胸腺移出

• 批准号: 2054732
• 负责人: IRVING GOLDSCHNEIDER
• 金额: $ 19.61万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-15 至 1997-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2054732
• 关键词: T lymphocyte; adrenalectomy; anergy; animal old age; apoptosis; calcium indicator; cell differentiation; cell sorting; cytotoxic T lymphocyte; enzyme linked immunosorbent assay; helper T lymphocyte; hyperglycemia; immunopathology; immunoregulation; interleukin 2; interleukin 4; isoantigen; leukocyte activation /transformation; mature animal; mutant; phenotype; thymus

The possible role of thymus involution in predisposing individuals to the consequences of immunological senescence has assumed great interest recently in view of the changing population demographics in our society. Although considerable information exists about the effects of decreased secretion of thymus humoral factors, relatively little is known about the roles that changes in the export of newly- formed T cells plays in immune senescence. Recently, results from our laboratory have shown that recent thymic emigrants (RTE's) and their immediate descendants in the rat can be selectively identified and isolated on the FACS by their expression of the Thy1.1 alloantigen, which is absent from mature T cells. In normal prepubertal rats, most RTE's had a CD4+8- or CD4-8+, TCR alpha beta hi RT6- CD45C- phenotype, and differentiated into Thy1- RT6+ CD45RC+ T cells within 7 days; whereas in antigen-stimulated rats most RTE's were partially activated (anergic?) lymphocytes, which expressed antigen-specific immunoregulatory (IR) activity, but did not proliferate to antigen or mitogen. We now propose to conduct detailed studies of the quantitative and qualitative changes in the output of RTE's in normal and antigen-stimulated rats as a function of progressive thymus involution. We also propose to determine the effect that the prevention or reversal of thymus involution has on the generation of RTE's, Specifically, we will attempt to determine if thymus involution is associated with alterations in: 1) the number of RTE's exported per unit time; 2)the phenotypic profiles of RTE's 3) the cell cycle kinetics of RTE's; 4) the functional properties of RTE's; 5) the ability of RTE's to phenotypically and functionally differentiate; and 6) the ability to generate immunoregulatory (IR) RTE's. To accomplish this, purified populations of RTE's and their immediate descendants will be isolated from normal rats before and at various stages during thymus involution and characterized phenotypically by 3- color FACS analysis. The shore-term fate (1-10 days) of RTE's will be studied by following their phenotypic differentiation proliferation apoptosis in a wave of RTE's released from the thymus after i.t. labeling with FITC. The functional capabilities of RTE's will be tested in in vitro assays for lymphocyte activation, lymphokine production, and helper suppressor cytotoxic activity. Limiting dilution analyses will be used to estimate the frequencies of reactive cells. In addition, the relative susceptibility of RTE's to the induction of tolerance with immobilized anti-CD3 will be assessed; and the immunoregulatory functions of IR-RTE's in antigen-stimulated (OA/ BGG in CFA) rats will be studied in a transwell culture system. Results obtained from animals undergoing thymus involution will then be compared with those obtained from age- and sex- matched rats in which thymus involution is inhibited (e.g. adrenalectomy and/or gonadectomy in prepubertal rats) or reversed (e.g. adrenalectomy, gonadectomy, or LHRH-agonist treated elderly rats). Similar studies will be conducted in adult mutant BUF/Mna strain rats, which display spontaneous thymus hyperplasia.

胸腺互动在诱发个体中的可能作用 免疫学衰老的后果假设很大 鉴于人口不断变化的人口统计，最近的兴趣 我们的社会。 尽管存在有关 胸腺体液因子分泌减少的影响，相对较 关于变化新出口的角色知之甚少。 形成的T细胞在免疫衰老中发挥作用。 最近，我们的结果 实验室表明，最近的胸腺移民（RTE）及其 可以选择性地识别大鼠的直接后代，并 通过表达Thy1.1同具有同具有同具有的表达，在FAC上孤立， 成熟的T细胞不存在。 在普通的青春期大鼠中，大多数 RTE具有CD4+8-或CD4-8+，TCR Alpha beta HI RT6- CD45C-表型， 并在7天内分为THY1-RT6+ CD45RC+ T细胞； 而在抗原刺激的大鼠中，大多数RTE被部分激活 （Anergic？）淋巴细胞，表达抗原特异性 免疫调节（IR）活性，但没有扩散到抗原或 有丝分裂原。 我们现在建议对 正常的RTE输出的定量和质量变化 和抗原刺激的大鼠作为进行性胸腺的函数 互动。 我们还建议确定 胸腺的预防或逆转对产生的产生 特别是，我们将尝试确定百里 互动与：1）RTE的数量有关 每单位时间出口； 2）RTE的表型曲线3）细胞 RTE的循环动力学； 4）RTE的功能特性； 5） RTE的表型和功能分化的能力；和 6）产生免疫调节（IR）RTE的能力。 为此，RTE的纯化人群及其即时 后代将从正常大鼠前后分离出来 胸腺相关期间的阶段，并通过3-表征表征 颜色FACS分析。 RTE的海岸期命运（1-10天）将是 通过遵循其表型分化增殖来研究 I.T.后从胸腺释放的RTE浪潮中的凋亡 用FITC标记。 RTE的功能功能将是 在体外测定中测试淋巴细胞激活，淋巴因子 生产和辅助抑制器细胞毒性活性。 限制 稀释分析将用于估计反应性的频率 细胞。 另外，RTE对 将评估使用固定的抗CD3诱导耐受性；和 IR-RTE在抗原刺激中的免疫调节功能（OA/ CFA）大鼠的BGG将在Transwell培养系统中进行研究。 然后，从经历胸腺相关的动物获得的结果将 将与年龄和性别匹配的大鼠获得的那些 抑制哪些胸腺相关性（例如肾上腺切除术和/或 前大鼠的性腺切除术）或反向（例如肾上腺切除术， GONADADADECTOMY，或LHRH-AGNIST治疗的老鼠）。 类似的研究 将在成年突变体BUF/MNA应变大鼠中进行 自发性胸腺增生。