Regulation of Cell survival Following T Cell Recognition

描述（由申请人提供）：这些研究人员先前已经展示了通过基因转导抗凋亡caspase抗性Bcl-2基因，实现人脐静脉内皮细胞（HUVEC）免受人细胞毒性T淋巴细胞（huCTL）的保护的有效策略。相比之下，用Bcl-2转导的猪主动脉内皮细胞（PAEC）对一些凋亡诱导剂有抗性，但对异种huCTL敏感。这些转导细胞系的敏感性比较表明，猪EC的敏感性与人EC相比，代表了功能的增加。敏感性的差异将根据Fas介导的信号通路的调节因素来表征，而caspase的激活程度将通过生物化学来表征。在此基础上，将进一步研究其他基因，以进一步实现PAEC的体外细胞保护。CD4和CD8 T细胞的活性都可以被调节性T细胞抑制，调节性T细胞可能在调节自身免疫和移植的发展中起重要作用。原型CD4+CD25+调节性T细胞将被分离出来，并在功能和生化上进行表征。这些调节细胞利用的机制来抑制与CD4和CD8 T细胞的同种和异种相互作用将进行比较。这些细胞类型为减少移植排斥提供了额外的策略。最后，利用SCID/beige小鼠的体内模型来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，非常有效地显示了Bcl-2转导对人体微血管的细胞保护作用。我们将利用该模型研究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.