Chronic DTH and IFN-gamma in Human Graft Arterioscleros*

人类移植动脉炎的慢性DTH和IFN-γ。移植物动脉硬化（GA）是一种宿主抗移植物免疫介导的病变，其特征在于内膜扩张、血管重构（病理性重塑）和血管调节异常。GA是心脏移植物慢性排斥反应的基础，是导致移植物衰竭的主要原因。目前还没有有效的治疗方法或早期诊断这种无情的进展性疾病的手段。GA的免疫发病机制尚不清楚。我们对心脏同种异体移植物动脉的早期免疫细胞化学分析表明，存在由动脉内膜内的非细胞溶解性T细胞介导的慢性迟发型超敏反应（DTH），该反应似乎与持续移植物内皮细胞（EC）上表达的同种抗原反应。由于啮齿类动物T细胞与EC的相互作用与人类中发生的相互作用有很大的不同，啮齿类动物移植模型可能限制了我们探索免疫发病机制。我们最近的工作表明，IFN-γ，一种由T细胞（即TH 1细胞）介导DTH的细胞因子，可以引起人类动脉内膜扩张。在本项目中，我们将使用人动脉细胞和器官培养模型以及异种移植到SCID小鼠（由Core B生产）中的人动脉来研究抗EC DTH的产生和慢性DTH对人血管的影响（项目1），并阐明IFN-γ诱导人动脉内膜扩张和其他变化的机制（项目2）。我们将通过使用常规形态学（包括免疫荧光、免疫细胞化学和原位杂交）以及激光捕获显微镜/逆转录-聚合酶链反应与人GA标本（由核心D分析）进行比较来验证这些模型。这些研究将辅以形态测量，以评估血管重塑和内膜连锁反应。这些研究将辅以形态测定法，以评估血管重塑和内膜增生（由Core C进行）、血管功能的生理学评估（由Core C进行）和分子表达谱分析（通过肽噬菌体展示、SELDI/蛋白质芯片分析和RNA阵列分析（分别由项目3、Core D和Core进行））。最后，我们将使用我们的人动脉异种移植物和其他模型来开发基于病理生理过程而不是终末期结构变化的早期非侵入性GA的新方法（项目3）。这一主题综合项目的结果将为解决慢性同种异体移植排斥问题的新的和更有效的方法提供科学依据。

Chronic DTH and IFN-gamma in Human Graft Arteriosclerosis. Graft arteriosclerosis (GA) is a host anti-graft immune-mediated lesion characterized by intimal expansion, vessel construction (pathological remodeling) and abnormal vasoregulation. GA is the underlying basis of chronic cardiac allograft rejection and the leading cause of allograft failure. There is currently no effective therapy or means of early diagnosis of this inexorably progressive disease. The immunopathogenetic mechanism(s) of GA is unknown. Our early immunocytochemical analysis of cardiac allograft allograft arteries suggested the presence of a chronic delayed type hypersensitivity (DTH) reaction mediated by non-cytolytic T cells within the arterial intima that appeared to be reacting to alloantigens expressed on persistent graft endothelial cells (EC). Since interactions of rodent T cells with EC are profoundly different from those that occur in humans, rodent transplant models may be of limited us in exploring immune pathogenetic mechanisms. Our more recent work has suggested that IFN-gamma, a cytokine made by T cells that mediate DTH (I.e. TH1 cells) can cause intimal expansion of human arteries. In this program project we will employ human artery cell and organ culture models as well as human arteries xenografted into SCID mice (produced by Core B) to investigate the development of anti-EC DTH and effects of chronic DTH on human vessels (Project 1) and to elucidate the mechanisms by which IFN-gamma induces intimal expansion and other changes of human arteries (Project 2). We will validate these models by comparisons to human GA specimens (analyzed by Core D) using conventional morphology (including immunofluorescence, immunocytochemistry and in situ hybridization) as well as laser capture microscopy/reverse transcription- polymerase chain reaction. These studies will be complemented with morphometry to assess both vascular remodeling and intimal chain reaction. These studies will be complemented with morphometry to assess both vascular remodeling and intimal hyperplasia (conducted by Core C) and physiological assessment of vessel function (conducted by Core C) and molecular expression profiling (via peptide phage display, SELDI/ProteinChip analysis and RNA array analysis (conducted by Project 3, Core D and Core, respectively). Finally, we will use our human artery xenografts and other models to develop new approaches for early non-invasive of GA based upon pathophysiologic processes rather than end stage structural changes (Project 3). The results of this thematically integrated program will provide a scientific basis for new and more effective approaches to address the problem of chronic allograft rejection.