EFFECT OF CYCLOSPORIN A ON TCR ONTOGENY AND AUTOIMMUNE DISEASE

最近的观察表明，环孢素A(CsA)阻断了TCR的启动 信号转导，从而导致TCR谱带选择异常。 CsA治疗可导致两种不同类型的明显自身免疫性疾病 实验模型。在这两个模型中，疾病的发展 需要CsA来源的自身反应细胞的存在 治疗的胸腺和外周T细胞的免疫调节异常。 初步数据显示CsA抑制胸腺对TCR2的选择 (Alphabeta TCR)谱系，但不是TCR1的胸腺成熟 (Gammadelta TCR)亚系。这些项目的广泛、长期目标 研究是为了确定这些不同T细胞的生理功能 并阐明外周免疫调节的性质 与容忍有关的活动。具体目标是测试三个 假设。 第一种假设是CsA既抑制正性也抑制负性 胸腺中TCR2谱系的选择，但不影响胸腺 TCR1细胞成熟。这一假设将通过确定 环孢素A对胸腺个体发育的影响 不同的TCR及其相关分子。这些研究将涉及 对小鼠和鸡T细胞发育的分析。重点将是 小鼠体内表达特定Vbeta基因的细胞的筛选 以及TCR3亚集的成熟，这是一种新的类似Alphabeta的TCR 鸡肉。 第二个假设是TCR1曲目是在外围设备中选择的 组织。这一假设将通过对发展的检验来检验。 和表达特定VGamma和TCR1细胞的组织归巢模式 VDelta基因。将使用两种实验方法：1)确定 CsA治疗导致特定组织归巢模式的抑制 利用某些VGamma基因的TCR1细胞的特征。2) 胸腺内注射FITC识别胸腺新近移居 周围组织和这些组织中VGamma使用模式的确定 细胞。 第三种假设是，在CsA诱导的自身免疫性疾病模型中， TCR2细胞介导自身反应，而TCR1细胞调节疾病 活动。将研究两种不同的实验模型：1)新生儿CsA 加上胸腺切除和2)接受致命性照射的成年人被同基因骨髓抢救 移植加钙治疗。这些模型将被建立，并且 不同T细胞亚群的出现频率和组织学定位 将通过免疫组织化学染色和流式细胞仪分析来表征。 在这两种模型中，“正常”T细胞的存在阻断了这种能力 自身反应性T细胞会导致实际的组织损伤。的表型 自身反应性效应细胞和“正常”调节细胞都会 使用磁活化细胞分选和领养 传输协议。

Recent observations indicate that cyclosporin A (CsA) blocks TCR initiated signal transduction and thus leads to abnormal TCR repertoire selection. CsA treatment can lead to overt autoimmune disease in two different experimental models. In both these models, the development of disease requires both the presence of autoreactive cells derived from the CsA treated thymus and an immunoregulatory abnormality in peripheral T cells. Preliminary data suggest that CsA inhibits thymic selection of the TCR2 (alphabeta TCR) repertoire, but not thymic maturation of the TCR1 (gammadelta TCR) sublineage. The broad, long-term objectives of these studies are to determine the physiologic function of these different T cell sublineages and to elucidate the nature of the peripheral immunoregulatory activity involved in tolerance. The specific aims are to test three hypotheses. The first hypothesis is that CsA inhibits both positive and negative selection of the TCR2 repertoire in the thymus, but does not affect thymic TCR1 cell maturation. This hypothesis will be tested by determining the effect of CsA on thymic ontogeny utilizing a panel of mAb which recognize different TCRs and associated molecules. These studies will involve analysis of both murine and chicken T cell development. The focus will be on the selection of cells expressing particular Vbeta genes in the mouse and the maturation of the TCR3 subset, a novel alphabeta-like TCR, in the chicken. The second hypothesis is that the TCR1 repertoire is selected in peripheral tissue. This hypothesis will be tested by examination of the development and tissue homing pattern of TCR1 cells expressing particular Vgamma and Vdelta genes. Two experimental approaches will be used: 1) determining if CsA treatment results in inhibition of specific tissue homing patterns characteristic of TCR1 cells which utilize certain Vgamma genes. 2) intrathymic injection of FITC to identify recent thymic emigrants in peripheral tissues and the determining the pattern of Vgamma usage in these cells. The third hypothesis is that in models of CsA induced autoimmune disease, TCR2 cells mediate autoreactivity, while TCR1 cells regulate disease activity. Two different experimental models will studied: 1) neonatal CsA plus thymectomy and 2) lethally irradiated adults rescued with syngeneic BM transplant plus Ca treatment. These models will be established and the frequency and histologic localization of the different T cells sublineages will be characterized by immunohistochemical staining and FACS analysis. In both these models, the presence of "normal" T cells blocks the ability of autoreactive T cells induce actual tissue lesions. The phenotype of both the autoreactive effector cells and the "normal" regulatory cells will be determined using magnetic activated cell sorting and an adoptive transfer protocol.