ALPS-like Patient with Cytokine Withdrawal Apoptotic Def

1例无已知突变的阿尔卑斯样患者被发现在与IL-2停用相关的T细胞凋亡方面存在独特的缺陷，但对星状孢子素、依托泊苷、顺铂和放射反应正常的T细胞和B细胞凋亡。这表明线粒体细胞死亡途径中可能存在明显的缺陷，一些候选蛋白可能是这种体外缺陷的原因。这导致了用来自患者的B细胞系进行蛋白质印迹分析，结果显示Bim、Bad、磷酸化Bad、Bak、Bax和Bcl-2的水平正常。此外，基因组DNA测序没有发现编码Bim的基因发生突变的证据，也没有证据表明编码Bak的基因发生了突变。鉴于明确显示的与细胞因子停用有关的细胞凋亡缺陷和候选蛋白的阴性研究，我们已经开始使用凋亡特异性和全人类基因组芯片对该患者的淋巴细胞与正常对照进行评估。同时，我们在此基础上进一步评估了细胞因子停用诱导细胞死亡的性质，因为体外功能研究结果表明，这一死亡途径具有不同于药物(依托泊苷、顺铂)和辐射诱导的其他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.