IDENTIFICATION OF THE XLP GENE

X连锁淋巴组织增生性疾病（XLP）是一种遗传性疾病， 免疫缺陷综合征，特征是对 EB病毒感染。而不是短暂传染 原发性暴露于EBV后单核细胞增多症，40-50%的XLP男孩 经历致命的不受控制的淋巴细胞增生，20-30%发展为 EBV相关淋巴瘤。因此，XLP代表了一种遗传模型， 研究EBV相关淋巴细胞增殖的机制， 肿瘤发生XLP还与EBV相关的 淋巴瘤见于HIV感染或免疫抑制患者 骨髓或实体器官移植后。这个目标 该项目的目的是鉴定和描述XLP的基因。通过RFLP 分析，XLP已与基因座Xq 25和迄今为止，3无关 据报道，患者在该基因座上共有细胞遗传学缺失。 为了确定受影响的基因，将采用定位克隆策略。 使用涉及以下方法：（1）将屏幕阵列YAC 在XLP基因座具有已知和新的遗传标记的文库， 产生跨越XLP缺失的YAC的线性重叠群， 通过产生一个编码序列， 从YAC DNA的粘粒文库，然后通过 “外显子扩增”技术，或通过该过程的cDNA克隆 （3）通过对转录本的分析， 与其他已知基因的同源性评估， 组织和物种之间的保护，并确认， 转录本是通过进行突变分析的参与基因， （4）评价XLP基因产物的性质 通过检查亚细胞定位、对细胞生长的影响 和增殖，与其他蛋白质的结合，以及 可能的动物模型。克隆XLP基因将提供更好的 了解EBV诱导淋巴瘤的机制， 宿主通过它识别并响应EBV感染的细胞。 XLP基因产物的特性可以为以下方面提供线索： 这些疾病和其他人类疾病的治疗策略 关于EBV

X-linked lymphoproliferative disease (XLP) is an inherited immunodeficiency syndrome characterized by increased susceptibility to Epstein-Barr virus (EBV) infection. Rather than transient infectious mononucleosis after primary exposure to EBV, 40-50% of boys with XLP experience fatal uncontrolled lymphoproliferation and 20-30% develop EBV-associated lymphoma. As such, XLP represents a genetic model to study mechanisms involved in EBV-associated lymphoproliferation and tumorigenesis. XLP also has clinical relevance to EBV-associated lymphomas seen in patients with HIV infection or those immunosuppressed after bone marrow or solid organ transplantation. The goal of this project is to identify and characterize the gene for XLP. Through RFLP analysis, XLP has been linked to the locus Xq25 and to date, 3 unrelated patients have been reported sharing cytogenetic deletions at this locus. To determine the affected gene, a positional cloning strategy will be used involving the following approaches: (1) To screen arrayed YAC libraries with known and novel genetic markers at the XLP locus and to generate a linear contig of YACs spanning the XLP deletion, (2) To identify coding sequences contained within these YACs by generating a cosmid library from YAC DNA and then either identifying exons through the "exon amplification" technique, or cDNA clones through the process of "direct selection", (3) To characterize transcripts through evaluation of homology to other known genes, pattern of expression among tissues and conservation between species, and to confirm that identified transcripts are the involved gene by performing mutational analysis of patient samples, (4) To evaluate properties of the XLP gene product through examination of subcellular localization, effects on cell growth and proliferation, association with other proteins, and generation of possible animal models. Cloning the XLP gene will provide a better understanding of the mechanisms through which EBV induces lymphoma and through which the host recognizes and responds to EBV-infected cells. Characterizing properties of the XLP gene product may provide clues to therapeutic strategies for these and other human diseases associated with EBV.