Caspase activation during PAH induced apoptosis

该建议的总体目标是确定在PAH介导的凋亡过程中发生在preB细胞中的分子事件。描述这些化合物的作用机制将增加我们对它们如何发挥其免疫毒性的理解。本研究的中心假设是，多环芳烃（PAHs）通过caspase-8以I型方式诱导淋巴细胞凋亡，从而导致preB细胞死亡。我的初步数据支持了这一假设，这些数据表明，用DMBA处理preB细胞可以激活caspase-8和caspase-3，并在较小程度上激活caspase-9。进一步的证据表明，可溶性FasL能够诱导preB细胞的caspase-8和凋亡。在拟议的项目中，我将进一步扩展这些发现，通过：1)表征前b细胞/基质细胞共培养系统中caspase激活和辅助蛋白诱导的特定模式；2)通过用DMBA治疗gold和lpr敲除小鼠，确定Fas/FasL通路在体内骨髓毒性中是否必要；3)定义多环芳烃的免疫毒性与caspase激活之间的关系，在体内和体外系统中使用前两个目标中开发的多环芳烃家族的其他成员。

The overall goal of this proposal is to determine the molecular events that take place in preB cells during PAH mediated apoptosis. Delineating the mechanism of action of these compounds will increase our understanding of how they exert their immunotoxicity. The central hypothesis of this proposal is that polycyclic aromatic hydrocarbons (PAHs) cause death of preB cells by inducing apoptosis in lymphocytes via caspase-8 in a Type I manner. This hypothesis is supported by my preliminary data, which show that treatment of preB cells with DMBA activates caspase-8 and caspase-3, and to a lesser extent caspase-9. Further evidence is provided that soluble FasL is able to induce caspase-8 and apoptosis in preB cells. In the proposed project I will extend these findings further by: 1) characterizing the specific pattern of caspase activation and accessory protein induction in the preB cell/stromal cell co-culture system; 2) determine if the Fas/FasL pathway is necessary for in vivo bone marrow toxicity, by treating gld and lpr knockout mice with DMBA; 3) define the relationship between immunotoxicity of the PAHs and caspase activating, using other members of the PAH family in the in vivo and in vitro systems developed in the first two aims.