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.

胸腺退化在个体易感性中的可能作用 免疫衰老的后果已被认为是巨大的 鉴于人口统计数据的变化，最近人们对 我们的社会。 尽管存在大量关于 胸腺体液因子分泌减少的影响 人们对新出口中角色的变化知之甚少 形成的T细胞在免疫衰老中发挥作用。 近日，我们的结果 实验室表明，最近的胸腺移民（RTE）及其 可以选择性地鉴定大鼠的直系后代 通过 Thy1.1 同种抗原的表达在 FACS 上分离， 成熟 T 细胞中不存在这种物质。 在正常青春期前的大鼠中，大多数 RTE 具有 CD4+8- 或 CD4-8+、TCR α beta hi RT6- CD45C- 表型， 并在7天内分化为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 （无能？）淋巴细胞，表达抗原特异性 免疫调节（IR）活性，但不增殖为抗原或 有丝分裂原。 我们现在建议进行详细研究 正常情况下 RTE 输出的量和质变化 和抗原刺激的大鼠作为进行性胸腺的功能 内卷化。 我们还建议确定 预防或逆转胸腺复旧对产生 RTE，具体来说，我们将尝试确定胸腺是否 复旧与以下方面的变化相关：1) RTE 的数量 单位时间导出； 2) RTE 的表型特征 3) 细胞 RTE 的循环动力学； 4) RTE 的功能特性； 5) 的 RTE 在表型和功能上区分的能力；和 6) 产生免疫调节（IR）RTE 的能力。 为了实现这一目标，需要纯化 RTE 群体及其直接 后代将在不同的时间之前和之后与正常大鼠分离。 胸腺退化过程中的各个阶段，其表型特征为 3- 彩色 FACS 分析。 RTE 的岸上命运（1-10 天）将是 通过跟踪它们的表型分化增殖来研究 i.t.后，胸腺释放一波RTE，导致细胞凋亡。 用 FITC 标记。 RTE 的功能能力将是 体外检测淋巴细胞活化、淋巴因子 产生和辅助抑制细胞毒活性。 限制 稀释分析将用于估计反应的频率 细胞。 此外，RTE 对 将评估固定化抗CD3的耐受诱导；和 IR-RTE 在抗原刺激（OA/ CFA) 大鼠中的 BGG 将在 Transwell 培养系统中进行研究。 从经历胸腺复旧的动物获得的结果将 与从年龄和性别匹配的大鼠中获得的结果进行比较 胸腺复旧受到抑制（例如肾上腺切除术和/或 青春期前大鼠的性腺切除术）或逆转（例如肾上腺切除术， 性腺切除术，或 LHRH 激动剂治疗的老年大鼠）。 类似的研究 将在成年突变 BUF/Mna 品系大鼠中进行，显示 自发性胸腺增生。