Regulation of Cell survival Following T Cell Recognition

描述（由申请人提供）：这些研究者先前已经显示了通过抗凋亡半胱天冬酶抗性Bcl-2基因的遗传转导实现人脐静脉内皮细胞（HUVEC）免受人细胞毒性T淋巴细胞（huCTL）的细胞保护的有效策略。与此相反，猪主动脉内皮细胞（PAEC）与Bcl-2转导耐一些诱导凋亡，但对异种huCTL敏感。这些转导系的敏感性的比较表明，猪EC的敏感性代表了与人EC相比时功能的获得。灵敏度的差异将通过调节Fas介导的信号传导途径的因子来表征，并且半胱天冬酶活化的程度将通过生物化学来表征。基于该表征，将检查其他基因以进一步实现体外PAEC的细胞保护。CD 4和CD 8 T细胞的活性都可以被称为调节性T细胞的细胞抑制，这可能在调节自身免疫和移植的发展中起重要作用。将分离原型CD 4 + CD 25+调节性T细胞，并在功能和生物化学上进行表征。将比较这些调节细胞用于抑制与CD 4和CD 8 T细胞的同种异体和异种相互作用的机制。这些细胞类型提供了减少移植排斥反应的额外策略。最后，使用SCID/beige小鼠的体内模型将用于评估细胞保护策略和调节性T细胞的功能。已经建立了一种方案，其非常有效地显示了Bcl-2转导对人微血管的细胞保护作用。我们将利用这个模型来研究使用猪微血管的细胞保护策略。

DESCRIPTION (provided by applicant): These investigators have previously shown effective strategies to achieve cytoprotection of human umbilical vein endothelial cells (HUVEC) from human cytotoxic T lymphocytes (huCTL) by genetic transduction of the anti-apoptotic caspase-resistant Bcl-2 gene. By contrast, porcine aortic endothelial cells (PAEC) transduced with Bcl-2 are resistant to some inducers of apoptosis but sensitive to xenogeneic huCTL. Comparison of the sensitivity of these transduced lines suggests that the sensitivity of porcine EC represents a gain of function when compared to human EC. The differences in sensitivity will be characterized with regard to factors regulating the Fas mediated signaling pathway and the extent of caspase activation will be characterized biochemically. Based on this characterization additional genes will be examined to further achieve cytoprotection of PAEC in vitro. The activity of both CD4 and CD8 T cells can be inhibited by cells known as regulatory T cells, which may play important roles in regulating development of autoimmunity and transplantation. The prototypic CD4+CD25+ regulatory T cells will be isolated and characterized functionally and biochemically. The mechanisms these regulatory cells utilize to inhibit allo- and xeno- interactions with CD4 and CD8 T cells will be compared. These cell types offer an additional strategy to reduce graft rejection. Finally, in vivo models using SCID/beige mice will be utilized to evaluate cytoprotective strategies and the function of regulatory T cells. A protocol has been established that very effectively shows cytoprotection of human microvessels by Bcl-2 transduction. We will utilize this model to study cytoprotective strategies using porcine microvessels.