Chemokines and T Cell Recruitment in High Risk Corneal Allograft Rejection

摘要 “高危”血管化角膜床受者的同种异体角膜移植物存活率很低，原因是 免疫排斥反应。我们的假设是，这些移植物与其他固体器官的命运相似 需要积极的全身免疫抑制才能改善的带血管同种异体移植 生死存亡。同种异体移植物的排斥反应是通过协调招募和渗透 同种异体特异性T细胞。最近，对固体免疫排斥反应的研究 带血管的同种异体器官移植表明，选择性趋化因子的早期诱导 T细胞在排斥反应中的最佳募集需要手术后的移植部位 异体移植。我们的数据显示，T细胞在移植物中的募集也是高危排斥反应的关键 带血管的同种异体角膜移植。这与中性粒细胞趋化物质的早期产生有关。 CXCL1/KC与T细胞趋化因子CXCL9/Mig的晚期上调 和CXCL10/IP10(干扰素诱导蛋白)。尽管CXCL1/KC的体内中和作用 结果在提高移植物存活率方面，我们最近的数据表明，CXCL10/IP10的中和导致 更快、更有力的拒绝。在本应用程序中，我们将检验这样一种假设，即高危血管 角膜的行为就像一个带血管的固体器官移植。CXCL1/KC的早期生产至关重要 与T细胞趋化因子的晚期诱导有关，而T细胞趋化因子是招募同种异体特异性效应物或 调节性的CD4T细胞进入移植物。本应用程序中提出的实验的总体目标是 了解角膜血运环境如何调节早期CXC趋化因子的产生 并将启动的同种异体特异性效应细胞和调节性T细胞招募到移植物中以调节 排斥反应。在目标1中，我们将使用一种跟踪抗原特异性T细胞的新系统进行测试，以 监测同种异体特异性T细胞的启动，并测试高危带血管同种异体角膜移植对这一变化的影响 这样一种方式，有更多的不同表型的T细胞最适合招募。在目标2中， 我们将确定CXCL1/KC的细胞来源，并测试CXCL1/KC是如何诱导T细胞后期产生的 通过增加产生干扰素的CXCR2+细胞的渗透来吸引细胞趋化。AIM中的实验 3将使用中和抗体和CXCL/9/Mig缺陷的小鼠来测试这个T细胞 趋化因子是移植物中T细胞募集增加的原因。我们还将利用 用荧光标记的效应器和调节性T细胞测试移植物内 趋化因子改变了它们的招募和移植结果。本文件中描述的实验结果 提案将确定开发新的治疗试剂的目标和抑制 高危同种异体移植物中T细胞的渗透。这最终将提高移植物的存活率，同时减少 依赖于现有的全身性和衰弱的免疫抑制方案。

ABSTRACT The survival rate of corneal allografts in "high risk" vascularized corneal bed recipients is poor due to immune rejection. Our hypothesis is that these grafts are similar to the fate of other solid organ vascularized allogeneic grafts that require aggressive systemic immune-suppression to improve survival. The rejection of allografts is mediated through the coordinated recruitment and infiltration of allo-specific T cells. Most recently, studies investigating the immunological rejection of solid vascularized organ allotransplants have shown that the early induction of selective chemokines at the site of transplantation after surgery is required for the optimal recruitment of T cells into rejecting allografts. Our data shows that recruitment of T cells into the graft is also critical in rejection of high risk vascularized corneal allografts. This correlates to the early production of the neutrophil chemoattractant CXCL1/KC and late up-regulation of the T cell chemoattractants: CXCL9/Mig (monokine induced by IFN-¿) and CXCL10/IP10 (IFN-¿-inducible protein). Although the in vivo neutralization of CXCL1/KC results in increased graft survival, our recent data shows that neutralization of CXCL10/IP10 causes a faster and robust rejection. In this application we will test the hypothesis that a high risk vascularized cornea behaves like a vascularized solid organ transplant. The early production of CXCL1/KC is crucial to the late induction of T cell chemoattractants necessary for the recruitment of allo-specific effector or regulatory CD4 T cells into the graft. The overall goal of the experiments proposed in this application is to understand how the vascularized corneal environment regulates early CXC chemokine production and the recruitment of primed allo-specific effector and regulatory T cells into the graft to mediate rejection reactions. In Aim 1, we will test using a novel system of tracking antigen specific T cells, to monitor allo-specific T cells priming and test this is altered by high risk vascularized corneal allografts in such a way that there are more T cells with a different phenotype optimized for recruitment. In Aim 2, we will identify the cell source of CXCL1/KC and test how CXCL1/KC induces the late production of T cell chemoattractants by increasing infiltration of CXCR2+ cells that produce IFN-¿. Experiments in Aim 3 will use neutralizing antibodies and mice deficient in CXCL/9/Mig to test that this T cell chemoattractant is responsible for the increased recruitment of T cells into the graft. We will also utilize novel animal models with fluorescently labeled effector and regulatory T cells to test how intragraft chemokines alter their recruitment and graft outcome. The results from experiments described in this proposal will identify targets for the development of novel therapeutic reagents and strategies to inhibit T cell infiltration into high risk allografts. This will ultimately improve graft survival while decreasing the dependence on the generalized and debilitating immunosuppressive regimens currently available.