Development of novel strategies to modulate human NK cell response in xenotransplantation

项目总结 异种移植(即利用人的猪器官进行跨物种移植)提供了一种潜在的解决方案 解决持续的器官短缺问题。器官短缺对非洲等少数群体的影响更严重 美国人、亚洲人和西班牙人。然而，猪与人的不相容会导致破坏性的人类免疫。 猪器官的反应和最终排斥反应。这项提议的长期目标是开发一种有效的 和安全的方法来防止人类对移植的猪细胞、组织和器官的免疫反应。 人NK细胞介导的猪内皮细胞直接杀伤是异种移植的障碍之一。 猪细胞配体和人NK细胞受体相互作用的信号平衡决定了人NK 细胞功能。这项建议的重点是操纵猪细胞表面蛋白来抑制/阻断NK细胞 识别和激活。在我们初步数据中，我们已经证明了人类白细胞抗原G在猪身上的表达 细胞抑制NK细胞的激活，减少促炎细胞因子的产生。一种抗体介导的- 阻断NKG2D受体可降低NK细胞的活性。我们假设对猪的操纵 配体可取消人NK细胞介导的细胞毒作用。抑制性配体的表达与去除 激活猪细胞上的配体可诱导NK细胞耐受和抑制。假设将是 本实验的具体目的如下：1)测定丹参对人NK细胞的抑制作用 HLAI类分子HLAC、HLAE、HLAG在猪细胞上的共表达；2)确定 NKG2D猪配体的消除是否会阻止人类NK细胞的识别和激活。这 探索性研究将扩大我们对跨物种免疫识别和 反应，开发一种新的方法来诱导局部免疫耐受/接受，并指导工程 满足猪的异种移植需求。

PROJECT SUMMARY Xenotransplantation (i.e. cross-species transplantation using pig organ in human) offers a potential solution to address persistent organ shortage. Organ shortage more severely impacts minorities, such as African Americans, Asians, and Hispanics. However, pig-human incompatibility results in destructive human immune response and ultimate rejection of pig organs. The long-term goal of this proposal is to develop an effective and safe method to prevent the human immune response to transplanted pig cells, tissues, and organs. Human NK cell mediated-direct killing of porcine endothelial cells is one of the barriers in xenotransplantation. A balance of signals from porcine cell ligands and human NK cell receptors interaction determines human NK cell function. This proposal focuses on manipulation of porcine cell surface proteins to inhibit/block NK cells recognition and activation. In our preliminary data, we have demonstrated that expression of HLA-G on porcine cell inhibits NK cell activation and reduces pro-inflammatory cytokine production. An antibody mediated- blocking of NKG2D receptor can diminish NK cell activation. We hypothesize that manipulation of porcine ligands may abolish human NK cell-mediated cytotoxicity. Expression of inhibitory ligands and removal of activating ligands on porcine cells may induce NK cell tolerance and inhibition. The hypothesis will be addressed in the experiments of the following Specific Aims: 1) to determine the inhibition of human NK cell by co-expression of HLA class I molecules HLA-C, HLA-E, and HLA-G on porcine cells; and 2) to determine whether elimination of NKG2D porcine ligands blocks human NK cell recognition and activation. This exploratory study will expand our understanding of the mechanism of cross-species immune recognition and response, develop a novel approach to induce local immune tolerance/acceptance, and guide engineering of pigs to meet xenotransplantation needs.