GENETIC REGULATION OF LYMPHOID DIFFERENTIATION ANTIGENS

人类白细胞抗原II类细胞表面分子在细胞中的重要作用 参与免疫反应的相互作用和II类基因的特异性等位基因 抗原似乎增加了对某些疾病的易感性，可能是通过 它们的免疫功能。人类白细胞抗原II类基因在一种 复杂的方式，构成表达，诱导表达，或不表达 表达，取决于所检查的细胞类型及其所处的阶段 差异化。这一应用提出了各种分子和基因 研究第二类基因调控的方法。人类白细胞抗原的体细胞杂交体 II类表达和非表达及可诱导的细胞类型和突变体 将通过互补性分析确定不同的组合 第II类表达所依据的因子、途径或亚基的数量 监管。来自这个实验室的初步证据表明，他们的 是II类基因的反式正调节因子，它起作用 从转录上讲。这项提议的一个主要目的是描述 推测的第二类表达调控因子，以及它的位置和方式 行动。对拟议的交易调节器的检测将发展为 监管者可以被描述成。分离的低水平突变体 将对单个II类基因的mRNA进行研究，以确定是否 损伤是转录的。转录缺陷的II类基因和 他们从中衍生出的正常基因将被克隆。的能力 与正常和转录缺陷基因结合的调节分子 突变基因和诱导DNase I超敏反应将被确定。 具有转录损伤的突变基因的基因组克隆将是 部分测序以绘制受影响的核苷酸位置。另一个 这个应用程序的主要目标是克隆II类病毒的编码基因 以确定其基因产物如何运作，并 将其结合的序列映射到人类白细胞抗原II类基因或其周围。

HLA Class II cell surface molecules have important roles in cell interactions involved in immune responses, and specific alleles of Class II antigens appear to confer susceptibility to certain diseases, probably by virtue of their immune functions. HLA Class II genes are regulated in a complex manner, being constitutively expressed, inducibly expressed, or not expressed, depending on the cell type examined and its stage of differentiation. This application proposes various molecular and genetic approaches to study Class II gene regulation. Somatic cell hybrids of HLA Class II expressing and non-expressing and inducible cell types and mutants will be made in various combinations to define by complementation analysis the number of factors, pathways or subunits by which Class II expression is regulation. Preliminary evidence from this laboratory suggests that their is a transactive positive regulator of Class II genes which acts transcriptionally. A major aim of this proposal is to characterize the putative regulator of Class II expression, and its site and mode of action. Assays for the proposed transactive regulator will be developed so that the regulator can be characterized. Isolated mutants with low levels of a single Class II gene mRNA will be studied to determine whether the lesions are transcriptional. Transcription defective Class II genes and the normal genes from which they derived will be cloned. The ability of the regulatory molecule to bind to the normal and transcription-defective mutant genes and to induce DNase I hypersensitivity will be determined. Genomic clones of mutant genes with transcriptional lesions will be partially sequenced to map the affected nucleotide positions. The other major goal of this application is to clone the gene coding for the Class II transactive regulator, to determine how its gene product operates, and to map the sequences it binds in to or around HLA Class II genes.