ISOLATION OF THE CHEDIAK HIGASHI IMMUNE DEFICIENCY GENE

Chediak-Higashi综合征是人类的一种原发性免疫缺陷病 (CHS)和小鼠（米色，BG）。受影响的个人有缺陷 粒细胞和自然杀伤细胞活性，特异性巨囊泡 在许多细胞类型中，通常在儿童期死于感染或 恶性肿瘤有强有力的证据表明，人类CHS与 小鼠中的BG位点。自从试图确定遗传缺陷， CHS直接受到缺乏染色体分配的阻碍， CHS或家系足够的连锁分析，我们已经进行了 bg的定位克隆作为鉴定CHS的先决条件 基因 定位克隆是鉴定疾病基因的一种方法 仅仅根据它的染色体位置，而不考虑病因。我们 初步实验有：1.局部bg为0.24+/-0.17厘摩 小鼠13号染色体上的间隔; SB/LeJ-bg小鼠中的该间隔; 3.特征3酵母人工 染色体（YAC），可以跨越这种重排。 我们建议 通过检测bg小鼠中表达的缺陷基因， 从这些YAC衍生的序列用于突变。的人同系物 bg基因将在CHS患者和正常人中克隆和测序 个体识别CHS突变。CHS基因的分离将 允许进行产前基因诊断， 婴儿期的CHS。bg基因的鉴定将有助于 了解蛋白质运输的调节机制， 溶酶体，以及囊泡分选对免疫的贡献 细胞毒性等功能。鉴于选择性损害 在BG小鼠中明显的某些免疫应答， 这种疾病的分子基础可能表明一种新的免疫方法， 调制，并暗示治疗CHS，目前还没有 认为，并将提供一个起点的基因治疗CHS。

Chediak-Higashi syndrome is a primary immune deficiency disease of human (CHS) and mouse (beige, bg). Affected individuals have defective granulocyte and Natural Killer cell activity, pathognomonic giant vesicles in many cell types, and typically die in childhood of infection or malignancy. There is strong evidence that human CHS is homologous to the bg locus in the mouse. Since attempts to identify the genetic defect in CHS directly have been thwarted by absence of chromosomal assignment of CHS or pedigrees adequate for linkage analysis, we have undertaken positional cloning of bg as an antecedent to identification of the CHS gene. Positional cloning is an approach to identifying a disease gene based solely on its chromosomal location, without regard to etiology. Our preliminary experiments have: 1. Localized bg to a 0.24+/-0.17 centiMorgan interval on mouse chromosome 13; Identified a genomic rearrangement within this interval in the SB/LeJ-bg mouse; 3. Characterized 3 yeast artificial chromosomes (YACs) which may span this rearrangement. We propose to identify the defective gene in the bg mouse by examining expressed sequences derived from these YACs for mutations. The human homolog of the bg gene will be cloned and sequenced in CHS patients and normal individuals to identify CHS mutations. Isolation of the CHS gene will permit prenatal genetic diagnosis, enabling institution of treatment for CHS in infancy. Identification of the bg gene will facilitate understanding of mechanisms of regulation of protein trafficking to lysosomes, and of the contribution of vesicular sorting to immune functions such as cellular cytotoxicity. Given the selective impairment of certain immune responses evident in bg mice, identification of the molecular basis of this disease may suggest a novel approach to immune modulation, and imply therapies for CHS which are not currently being considered, and will provide a starting point for gene therapy of CHS.