ENVIRONMENTAL STRESS, APOPTOSIS & SYSTEMIC AUTOIMMUNITY

我们实验室最近的观察结果表明，Fas/FasL 系统是UV-B和伽马辐射损伤后细胞凋亡的关键介质 辐射，以及热休克。因为Fas/FasL相互作用 对控制自身免疫至关重要，正如LPR和 GLD突变小鼠品系，我们假设自身免疫性疾病可能 依赖于有效的Fas调节和有效的诱导 损伤细胞中的细胞凋亡。在这个提案中，我们将学习生物学 损伤后使用正常细胞上调Fas的情况，尤其是 强调P53分子的作用。我们特别是 对P53的S在自身免疫中的作用感兴趣，因为我们的罢工 初步数据显示，P53基因缺陷的小鼠产生高滴度 自身抗体。我们推测P53可能通过Fas作用于 损伤细胞的凋亡，而p53-/-小鼠可能无法 消除这种细胞，并可能保留潜在的自体免疫细胞。 我们将测试Fas和P53在介导局部病理中的作用 在系统性自身免疫性疾病中，通过暴露正常和突变的小鼠 至电离辐射和UV-B辐射。最后，我们将延长初步的 用Fas结合M13噬菌体克隆研制试剂的数据 修饰Fas介导的细胞凋亡，既作为激动剂又作为拮抗剂。我们会 合成激动型和拮抗型Fas结合肽 我们从噬菌体展示中鉴定的Fas结合噬菌体序列 并将评估它们诱导和阻断细胞死亡的能力 在体内和体外。总体而言，拟议的研究应有助于澄清 Fas在免疫损伤和系统性自身免疫性疾病中的作用 它作为对环境作出反应的前哨分子参与其中 压力。

Recent observations from our laboratory have implicated the Fas/FasL system as a key mediator of apoptosis following injury by UV-B and gamma irradiation, as well as heat shock. Because Fas/FasL interactions are critical to the control of autoimmunity, as illustrated by the lpr and gld mutant mouse strains, we hypothesize that autoimmune disease may depend on effective Fas regulation and the efficient induction of apoptosis in injured cells. In this proposal, we will study the biology of Fas upregulation after injury using normal cells, with particular emphasis on the role of the p53 molecule. We are particularly interested in P53's role in autoimmunity because of our striking preliminary data that mice deficient in p53 develop high-titer autoantibodies. We hypothesize that p53 may act via Fas to induce apoptosis of injured cells, and that the p53-/- mice may be unable to eliminate such cells and may retain potentially autoimmunogenic cells. We will test the role of both Fas and p53 in mediating local pathology and in systemic autoimmune disease by exposing normal and mutant mice to ionizing and UV-B radiation. Finally, we will extend our preliminary data using Fas-binding M13 bacteriophage clones to develop reagents to modify Fas-mediated apoptosis, both as agonists and antagonists. We will synthesize agonistic and antagonistic Fas-binding peptides based on sequences of Fas-binding phages we have identified from a phage display library, and will assess their ability to induce and to block cell death in vivo and in vitro. Overall, the proposed studies should help clarify the role of Fas in immune injury and systemic autoimmune disease, and its participation as a sentinel molecule which responds to environmental stress.