SIGNAL TRANSDUCTION VIA THE CD4 MOLECULE

这项建议描述了单克隆体的特征 一种抗体，称为6B10，与部分CD4分子结合 参与了艾滋病毒/艾滋病病毒的绑定。6B10的结合 对CD4T细胞也会导致生化反应的产生 在淋巴细胞激活中重要的信号，即动员 细胞内钙(CA)的含量。这发生在没有 CD3/TCR复合体提示CD4分子直接 参与了这些生化信号的转导。6B10 也抑制OKT3/CD3诱导的T细胞增殖和OKT3/CD3- 诱导钙动员。这表明信号转导 通过CD4可能在调节T细胞增殖中起重要作用。 由于6B10结合到与HIV结合有关的CD4区域，所以它是 因此推测HIV可能启动了钙动员。 如果HIV影响T细胞功能的方式类似于 6B10，这表明HIV参与了T细胞的激活 并可能有助于解释一些定性的发病机制。 艾滋病患者的CD4T细胞异常。这 假说将通过比较艾滋病毒和 6B10关于它们诱导钙变化的能力以及 影响T细胞增殖、IL-2产生及IL-2受体 表情。CD4分子的区域在人类免疫系统中起重要作用 这些生化信号的产生也将被确定。 这将使用定点突变来改变部分基因 编码CD_4胞浆内尾部的基因 分子。突变的cdna将被插入到CD4-T细胞系中， Jurkat，并从钙动员的角度以及在 IL-2产生和IL-2受体表达。理解 CD4分子如何影响人体内的生物化学事件 淋巴细胞活化可能有助于更好地理解 HIV和CD4之间的相互作用参与了人类免疫缺陷病毒的发病 艾滋病患者的免疫缺陷。

This proposal describes the characteristics of a monoclonal antibody, termed 6B10, that binds to a portion of the CD4 molecule involved in the binding of the HIV/AIDS virus. The binding of 6B10 to CD4+ T cells also results in the generation of biochemical signals important in lymphocyte activation, namely the mobilization of intracellular calcium (CA++). This occurs in the absence of the CD3/TCR complex suggesting that the CD4 molecule is directly involved in the transduction of these biochemical signals. 6B10 also inhibited OKT3/CD3-induced T cell proliferation and OKT3/CD3- induced Ca++ mobilization. This suggests that signal transduction by CD4 may be important in the regulation of T cell proliferation. Since 6B10 binds to a region of CD4 involved in HIV binding, it is therefore hypothesized that HIV may initiate Ca++ mobilization. If HIV affects T cell function in a manner similar to that seen by 6B10, this would suggest involvement of HIV in T cell activation and may help explain the pathogenesis of some of the qualitative abnormalities of CD4+ T cells seen in patients with AIDS. This hypothesis will be investigated by comparing the effects of HIV to 6B10 in terms of their ability to induce changes in Ca as well as affect T cell proliferation, IL-2 production and IL-2 receptor expression. The region of the CD4 molecule important in the generation of these biochemical signals will also be determined. This will be done using site-directed mutagenesis to alter portions of the cDNA coding for the intracytoplasmic tail of the CD4 molecule. Mutant cDNA's will be inserted in the CD4- T cell line, Jurkat, and studied in terms of Ca++ mobilization as well as in IL-2 production and IL-2 receptor expression. The understanding of how the CD4 molecule affects the biochemical events of lymphocyte activation may lead to an improved understanding of the interactions between HIV and CD4 involved in the pathogenesis of the immunodeficiency seen in patients with AIDS.