STRUCTURAL BASIS OF CD59 AND CD58 SIGNALING TO T CELLS

描述(改编自申请者摘要)：这是一份竞争性的 续签申请。这个项目的目标是描述特定的 在异种和异种免疫应答过程中激活的共刺激通路 内皮细胞。研究已经确定了对以下各项反应的共同属性 人类和猪的ECs也发现了一个重大的重要区别 关于B7的表达。有很大的序列差异 在细胞表面抗原之间的这些抗原和它们的贡献 通过配基相互作用发出的信号可能有很大的不同。 人T细胞对猪内皮细胞的反应比人强得多 异体血管内皮细胞。这是直接承认MHC I类的结果 和II类抗原，以及猪内皮细胞上pB7.2的存在。这个 CD58、CD59在CD2通路中的作用及pB7.2在CD28通路中的作用 我们将研究Xeno的响应。人类T细胞的激活将是 使用补充办法进行评估。 不同配体相互作用对转基因CHO细胞的贡献 将单独或结合进行检查。这将包括正常 和人类CD58和CD59抗原的突变形式以及正常形式的 这些同源的猪抗原。此外，更复杂的抗原 在去除确定的抗原后，将对呈递细胞进行研究。几个 将采用特定的策略来抑制细胞表面 SLA抗原和共刺激分子(pB7.2、CD59、CD58)的表达 在人和猪的内皮细胞上。主要和召回响应都将是 已评估。 人类T细胞识别SLA抗原的能力将通过以下方法进行研究 在转基因细胞上表达这些抗原。SLA抗原的识别 在没有共刺激信号的情况下可能会导致诱发无能 人类T细胞。SLA抗原Plus基因导入NIH3T3细胞的研究 其他的共刺激分子将被用来定义 打破无能为力的要求。人与猪的比较 将建立系统，以定义可能是 促进组织移植的目标。最后，申请者将 利用体内模型，其中SCID小鼠的免疫系统已经 用人类细胞重组。猪瘟病毒的免疫原性 表现出识别能力改变的转基因猪内皮细胞 在此模型中将在形成后评估培养中的特性 胶原蛋白凝胶中的合成血管网络。

DESCRIPTION (Adapted from the Applicant's Abstract): This is a competitive renewal application. The goals of this project are to characterize specific costimulatory pathways invoked during allo and xeno immune responses to endothelium. Studies have defined common properties of the responses to human and porcine ECs but also have identified a major important difference regarding the expression of B7. There are substantial sequence differences in the cell surface antigens between these antigens and their contribution to signaling via ligand interactions may differ significantly. The response of human T cells is much stronger to porcine ECs than human allogeneic ECs. This is a consequence of direct recognition of MHC class I and class II antigens as well as the presence of pB7.2 on porcine ECs. The role of CD58 and CD59 in the CD2 pathway and pB7.2 in the CD28 pathway in xeno responses will be studied. The activation of human T cells will be assessed using complementary approaches. The contribution of distinct ligand interactions on transfected CHO cells individually or in combination will be examined. This will include normal and mutant forms of human CD58 and CD59 antigens as well as normal forms of these homologous porcine antigens. In addition, more complex antigen presenting cells will be studied after removing defined antigens. Several strategies will be employed to specifically inhibit the cell surface expression of SLA antigens and costimulatory molecules (pB7.2, CD59, CD58) on human and porcine ECs. Both primary as well as recall responses will be evaluated. The ability of human T cells to recognize SLA antigens will be studied by expressing these antigens on transfected cells. Recognition of SLA antigens in the absence of a costimulatory signal may result in induction of anergic human T cells. Transfections of NIH3T3 cells with SLA antigens plus additional costimulatory molecules will be utilized to define the requirements for breaking anergy. Comparisons between human and porcine systems will be made in order to define the critical pathways that could be targets for facilitating tissue transplants. Finally, the applicants will utilize an in vivo model in which the immune system of SCID mice has been reconstituted with human cells. The immunogenic properties of the transfected porcine ECs that have demonstrated altered recognition properties in culture will be evaluated in this model after formation of synthetic vascular networks in collagen gels.