STRUCTURAL BASIS OF CD59 AND CD58 SIGNALING TO T CELLS

描述（改编自申请人的摘要）：这是一个竞争性的 续期申请。 该项目的目标是描述特定的 在同种和异种免疫应答过程中激活的共刺激途径 内皮细胞 研究已经确定了对以下问题的反应的共同特性： 但是也已经确定了一个主要的重要差异， 关于B7的表达。 它们之间存在着实质性的序列差异 在细胞表面抗原之间的这些抗原和它们的贡献 通过配体相互作用的信号传导可能会有很大的不同。 人T细胞对猪内皮细胞的反应比人强得多 同种异体内皮细胞 这是直接识别MHC I类的结果 和II类抗原以及pB7.2的存在。 的 CD58和CD59在CD2通路中的作用以及pB7.2在CD28通路中的作用， 将研究异种反应。 人类T细胞的激活将是 使用互补方法进行评估。 不同配体相互作用对转染CHO细胞的贡献 将单独或组合进行检查。 这将包括正常 和突变形式的人CD58和CD59抗原以及正常形式的 这些同源的猪抗原。 此外，更复杂的抗原 在除去确定的抗原后研究呈递细胞。 几 将采用特异性抑制细胞表面 SLA抗原和共刺激分子（pB7.2、CD59、CD58）的表达 在人类和猪的内皮细胞上。 主要响应和召回响应都将是 评估。 人T细胞识别SLA抗原的能力将通过以下方法研究： 在转染的细胞上表达这些抗原。 SLA抗原的识别 在缺乏共刺激信号的情况下，可能导致无反应性的诱导。 人类T细胞 用SLA抗原加 将利用另外的共刺激分子来定义 打破无反应性的要求。 人与猪的比较 将制定系统，以确定关键途径， 用于促进组织移植的靶点。 最后，申请人将 利用体内模型，其中SCID小鼠的免疫系统已被 用人体细胞重组 的免疫原性性质 转染的猪EC已经证明了改变的识别 在培养物中的性质将在形成后在该模型中进行评价。 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.