LYMPHOBLAST MODEL FOR DISEASES OF PURINE METABOLISM

遗传性腺苷脱氨酶(ADA)缺陷导致严重的联合 婴儿时期的免疫缺陷疾病(SCID)，以及更隐蔽的 在儿童和青春期发展的免疫功能障碍的形式 (起病晚)。这个实验室的长期目标是 了解免疫缺陷的生化和分子基础，以及 利用这些信息来开发有效的治疗方法。的目标是 目前的建议是评估ADA缺乏的遗传基础 同时患有SCID和晚发性ADA缺乏症的患者改善 了解特定突变影响稳定性的机制 和ADA在免疫系统细胞中的活性，以及 决定疾病严重程度和反应的特定突变 聚乙烯酶置换法恢复ADA活性的研究 乙二醇化腺苷脱氨酶(PEGADA)。这些问题的答案是 问题与了解病人的反应同样相关。 体细胞ADA基因转导的各种方法。具体的 本建议的目的是：L)表征突变的ada基因 接受PEG-ADA治疗的免疫缺陷患者，以及 研究这些突变与酶的程度的关系 缺乏、代谢异常、临床严重性和对 心理治疗。2)在体外和培养细胞中研究其用途 一种新的方法，使用序列特异性反义寡核苷酸， 增强具有影响基因突变的患者的正常ADA表达 ADA基因的剪接。我们还将调查这一假设 选择性剪接有助于某些患者体内残留的ADA活性 有拼接缺陷。3)研究突变体之间的相互作用 AdA蛋白与CD26/ADA复合蛋白，以确定是否 这种相互作用可能影响ADA的折叠和稳定性，从而 确定残留ADA活性和临床严重程度。

Inherited deficiency of adenosine deaminase (ADA) causes severe combined immunodeficiency disease (SCID) in infancy, as well as more insidious forms of immune dysfunction that develop during childhood and adolescence (late onset). The long term objectives of this laboratory have been to understand the biochemical and molecular basis for immunodeficiency, and to use this information in order to develop effective therapy. The aims of the present proposal are to evaluate the genetic basis of ADA deficiency in patients with both SCID and late onset ADA deficiency to better understand the mechanisms by which specific mutations affect the stability and activity of ADA in cells of the immune system, and the role of specific mutations in determining both disease severity and the response to restoration of ADA activity by enzyme replacement with polyethylene glycol-modified adenosine deaminase (PEG-ADA). The answers to these questions are equally relevant to understanding the response of patients to various methods of somatic cell ADA gene transduction. The specific aims of the present proposal are: l) To characterize the mutant ADA genes of immunodeficient patients under treatment with PEG-ADA, and to investigate the relationship of these mutations to the degrees of enzyme deficiency, metabolic abnormality, clinical severity, and response to therapy. 2) To investigate, both in vitro and in cultured cells, the use of new approach, using sequence-specific antisense oligonucleotides, to enhance normal ADA expression in patients with mutations that affect the splicing of ADA mRNA. We will also investigate the hypothesis that alternative splicing contributes to residual ADA activity in some patients with splicing defects. 3) To investigate the interaction between mutant ADA proteins with the CD26/ADA complexing protein, to determine whether this interaction might influence ADA folding and stability, and thereby determine residual ADA activity and clinical severity.