STRUCTURE AND FUNCTION OF TOXIC SHOCK SYNDROME TOXIN 1

中毒性休克综合征毒素-1(TSST-1)与 急性起病多系统中毒性休克综合征的发病机制 无序。这种金黄色葡萄球菌外毒素能激活T- 淋巴细胞和巨噬细胞导致细胞因子的诱导。这个 这种毒素强大的免疫调节作用很可能是一个关键 在中毒性休克综合征发病机制中的作用。的总目标是 这项提议是定义结构与功能的相关性 利用突变分析该毒素的各种生物效应。突变型 TSST-1毒素将使用定点突变产生在 克隆的基因。突变株TSST-1将接受诱导能力测试 巨噬细胞分泌细胞因子并激活T细胞。这种方法 上是否存在功能不同的站点 毒素分子。突变的毒素也将被用于研究 TSST-1、T细胞受体(TCR)与MHC类分子的相互作用 II类分子--启动T细胞有丝分裂的关键事件 由TSST-1提供。将对TSST-1突变体进行结合能力测试 第二类MHC分子。相反，表达突变类的细胞系 第二类MHC抗原将被用来定义第二类分子上的位点 与本地的TSST-1相互作用。T细胞受体与T细胞的相互作用 TSST-1将通过比较T-T细胞上表达的TCR-Vbeta基因来研究 突变体TSST-1激活的细胞与野生型选择的细胞 TSST-1。这种带有特定亚群的T细胞的选择性激活 是TSST-1“超抗原”的特征。在……里面 总结，拟议工作将定义TSST-1分子上的 对毒素对T细胞和巨噬细胞的影响至关重要。 细胞受体与TSST-1的分子相互作用 毒素也将被定性。这些信息最终可以 用于了解TSST-1函数在 毒素休克综合征的发病机制。

Toxic shock syndrome toxin-1 (TSST-1) has been strongly implicated in the pathogenesis of toxic shock syndrome, an acute onset multisystem disorder. this staphylococcal exotoxin triggers the activation of T- lymphocytes and macrophages resulting in the induction of cytokines. The potent immunomodulatory effects of this toxin is likely to be a key factor in the pathogenesis of toxic shock syndrome. The overall goal of this proposal is to define structure-function correlations for the various biologic effects of the toxin using mutational analysis. Mutant TSST-1 toxins will be generated using site-directed mutagenesis on the cloned gene. Mutant TSST-1 will be tested for the ability to induce cytokine secretion by macrophages and to activate T-cells. This approach can be used to determine whether functionally distinct sites exist on the toxin molecule. The mutant toxins will also be used to study the interaction between TSST-1, the T-cell receptor (TCR) and the MHC class II molecules, a critical event in the initiation of T-cell mitogenesis by TSST-1. The TSST-1 mutants will be tested for the ability to bind to class II MHC molecules. Conversely, cell lines expressing mutant class II MHC antigens will be used to define the sites on the class II molecule that interact with native TSST-1. T-cell receptor interactions with TSST-1 will be studied by comparing the TCR-Vbeta genes expressed on T- cells activated by mutant TSST-1 with those selected by the wild-type TSST-1. This selective activation of T-cells bearing particular subsets of Vbeta elements is characteristic of the TSST-1 "superantigen". In summary, the proposed work will define sites on TSST-1 molecule which are critical for toxin-mediated effects on T-cells and macrophages. Molecular interactions between the cellular receptors and the TSST-1 toxin will also be characterized. This information can ultimately be used to understand the relative contribution of TSST-1 functions in the pathogenesis of toxin shock syndrome.