GAMMA/DELTA T CELLS IN TOLERANCE AND TUMOR IMMUNITY

我们计划测试这样一种假设，即伽马-德尔塔T细胞在 在对外源性和内源性抗原耐受中的作用。这个想法是基于 关于我们确定CD8 T细胞如何下调免疫的实验 回应。我们已经证明，外源抗原，如卵清蛋白(OVA) 与完全弗氏佐剂(CFA)混合，OVA特异性，MHC类 我有限制，CD8 CTL。这些CTL转移到幼稚的、同基因的 受体抑制卵清蛋白特异性反应，提示CTL可以 解释了CD8 T细胞的部分抑制活性。为了测试 CTL是否参与了一种典型的涉及抑制、口头的模型 对卵清蛋白的耐受性进行了研究。我们发现口服卵清蛋白确实有 不是启动CTL，而是抑制CTL的启动。此外，CD8 耐受小鼠脾T细胞将耐受转移给幼鼠 这表明并不是所有的抑制者都是CTL。此外，还可以进行前处理。 抗-γ-TCR抗体小鼠预防耐受诱导的研究 并逆转自身对胰岛素的耐受性。间接证据表明 抗-Gamma-Delta抗体干扰耐受诱导 耗尽伽马-德尔塔T细胞。此外，口服卵清蛋白也未能 在Gamma-Delta基因敲除小鼠中诱导耐受，提供额外的 支持这样的解释，即伽马-德尔塔T细胞在 在耐受诱导中的作用。 该项目的目标是确定伽马-三角洲T细胞的作用 以卵清蛋白作为外源性或内在抗原的耐受性 特别强调卵清蛋白作为一种肿瘤抗原。我们将测试是否 口服卵清蛋白诱导的CD8抑制T细胞是γ- Delta T细胞或Gamma-Delta T细胞是否调节 CD8抑制T细胞。我们将确定伽马-德尔塔T细胞 并生产T细胞克隆或杂交瘤以研究其 感受器。伽马-德尔塔T细胞在自我耐受中的作用也将是 使用表达OVA基因的转基因(TG)小鼠进行了研究。我们会 确定这些小鼠在CFA中是否对OVA耐受，以及是否抗 伽马-三角洲抗体逆转耐受性。转基因小鼠口服卵清蛋白治疗 确定γ-增量T细胞和/或CD8抑制T细胞是否 宽容。伽马-德尔塔T细胞可能参与 不能被排斥的肿瘤将使用EL4细胞进行测试 将OVA基因作为肿瘤模型进行表达。容忍或容忍的影响 将评估OVA对肿瘤排斥反应的免疫力，以及OVA对肿瘤排斥反应的影响 抗-γ-Delta抗体对肿瘤排斥反应的评估将在正常情况下进行 OVA转基因小鼠。共刺激分子对肿瘤细胞的杀伤作用 克服耐受性和诱导排斥反应将在正常组和TG组进行比较 老鼠。

We plan to test the hypothesis that gamma-delta T cells play an important role in tolerance to exogenous and endogenous antigens. This idea is based on our experiments determining how CD8+ T cells down regulate immune responses. We have shown that exogenous antigens, such as ovalbumin (OVA) mixed with complete Freund's adjuvant (CFA) primes OVA-specific, MHC class I restricted, CD8+ CTL. Transfer of these CTL to naive, syngeneic recipients inhibited OVA-specific responses suggesting that CTL could account for some of the suppressor activities of CD8+ T cells. To test whether CTL were involved in a typical model involving suppression, oral tolerance to OVA was studied. We found that oral administration of OVA did not prime CTL but rather inhibited the priming of CTL. in addition, CD8+ splenic T cells from tolerant mice transferred tolerance to naive mice suggesting that not all suppressors are CTL. Moreover, pretreatment of mice with anti-gamma-delta TcR antibody prevented tolerance induction by OVA and reversed self tolerance to insulin. Indirect evidence suggests that anti-gamma-delta antibody interferes with tolerance induction by depleting gamma-delta T cells. Also, oral administration of OVA failed to induce tolerance in gamma-delta knock out mice providing additional support for the interpretation that gamma-delta T cells play an essential role in tolerance induction. The goal of this project is to determine the role of gamma-delta T cells in tolerance using OVA as an extrinsic or an intrinsic antigen with particular emphasis on OVA as a tumor antigen. We will test whether the CD8+ suppressor T cells induced by oral administration of OVA are gamma- delta T cells or whether gamma-delta T cells regulate the activation of CD8+ suppressor T cells. We will determine whether gamma-delta T cells are OVA-specific and produce T cell clones or hybridomas to study their receptors. The role of gamma-delta T cells in self-tolerance also will be studied using transgenic (Tg) mice expressing the OVA gene. We will determine whether these mice are tolerant to OVA in CFA and whether anti- gamma-delta antibody reverses tolerance. Tg mice will be given oral OVA to determine whether gamma-delta T cells and/or CD8+ suppressor T cells are tolerant. The possibility that gamma-delta T cells could be involved in the failure of tumors to be rejected will be tested using EL4 cells expressing the OVA gene as a tumor model. The effect of tolerance or immunity to OVA on tumor rejection will be evaluated and the effect of anti-gamma-delta antibody on tumor rejection will be assessed in normal and OVA Tg mice. The ability of tumors transfected with co-stimulators to overcome tolerance and induce rejection will be compared in normal and Tg mice.