ALPS-like Patient with Cytokine Withdrawal Apoptotic Def

一名未发现突变的alps样患者在体外发现了一种独特的缺陷，即与IL-2停药相关的T细胞凋亡，而正常的T细胞和B细胞凋亡则对斯桃孢素、依托泊苷、顺铂和放疗有反应。这表明线粒体细胞死亡途径中存在明显缺陷的可能性，许多候选蛋白质可以解释这种体外缺陷。这导致使用来自患者的B细胞系进行蛋白质Western blot分析，显示Bim， Bad，磷酸化Bad， Bak， Bax和Bcl-2的水平正常。此外，基因组DNA测序显示，没有证据表明编码Bim和cDNA的基因发生突变，也没有证据表明编码Bak的基因发生突变。鉴于细胞凋亡的缺陷明显与细胞因子戒断和候选蛋白的阴性研究相关，我们已经开始使用细胞凋亡特异性和全人类基因组微阵列对该患者的淋巴细胞与正常人进行比较。同时，基于该患者，我们正在进一步评估细胞因子戒断诱导细胞死亡的性质，因为体外功能发现表明，这种死亡途径具有不同于其他药物（依托泊苷、顺铂）和照射诱导的线粒体死亡途径的明显特征。

An ALPS-like patient without an identified mutation has been found to have a unique in vitro defect in T cell apoptosis associated with IL-2 withdrawal but normal T cell and B cell apoptosis in response to staurosporine, etoposide, cisplatin and radiation. This suggests the possibility of a distinct defect in the mitochondrial cell death pathway with a number of candidate proteins that could account for this in vitro defect. This lead to protein analysis by Western blot using B cell lines from the patient that revealed normal levels of Bim, Bad, phosphorylated-Bad, Bak, Bax and Bcl-2. In addition sequencing of genomic DNA revealed no evidence of a mutation in the gene encoding Bim and using cDNA, no evidence of a mutation in the gene encoding Bak. In light of the clearly demonstrated defect in apoptosis uniquely associated with cytokine withdrawal and the negative studies of candidate proteins, we have begun evaluation of this patients lymphocytes compared to normals using apoptosis-specific and whole human genome microarrays. At the same time we are further evaluating the nature of cytokine withdrawal induced cell death based on this patients since the in vitro functional findings suggest that this death pathway has distinct features that differ from other mitochondrial death pathways induced by drugs (etoposide, cisplatin) and irradiation.