MOLECULAR BIOLOGY OF TSST-1 & OTHER SUPERANTIGEN TOXINS

描述（改编自申请人的摘要）：这是一个 竞争性更新的合作项目之间的诺维克和 施利弗特实验室的目标是了解分子遗传学 中毒性休克综合征是一种典型的超抗原 (TSST 1）。 他们的结果和其他人的结果表明， TSST 1与TCR和MHC II类受体的相互作用是 负责它们的超抗原活性。 但这些 研究人员提供的证据表明，它与不同的 其他细胞上的受体类型是其致命性的原因。 他们最近确定了TSST 1的结构， 衍生物的X射线晶体学，并构建了一系列的 突变体的特性导致了这个提议的一个假设， 即分别测定致死性和超抗原性。 前两个目标将集中在一个明确的测试这一假设 通过确认他们的初步结果， 可分离的功能 项目的这一部分将调查 TSST 1的病理生物学，通过鉴定和表征组织特异性 受体和确定细胞内细胞毒性的机制 关于毒素的突变形式的活性。 目标3和4将是对分子的持续研究。 遗传学S.金黄色葡萄球菌毒素产生。 目标3将侧重于 他们的初步遗传数据表明，TSST 1是由一个 转座子，Tn 557。 项目的这一部分将决定 Tn 557以及紧密连锁异源基因的结构和功能 含有SEB和某些抗性的决定簇的插入。 目标4将试图对下列相互排斥现象作出解释： TSST 1阳性和α-溶血素阳性的表型。金黄色， 尽管事实上许多菌株同时具有这两种基因。 类似的情况 存在于A组链球菌中，具有两种超抗原（SPEA和SPEB）。 他们已经获得了初步的结果，暗示了一个明确的 TSST 1和α溶血素之间的调节拮抗作用。 他们提出 以确定是否有其他外蛋白参与，以及 这种对立的基础。 他们将与SPEA进行类似的研究 的SPEB。 目的5将试图阐明甘油的作用机制 单月桂酸酯对真核细胞和S.金黄色。 在一系列 在不相关的实验中，他们观察到GML抑制了 TSST 1和其他外蛋白的合成以及诱导 对几种抗生素的耐药性，可能是通过干扰信号 转导 此外，他们还表明GML对T细胞有丝分裂有促进作用， 淋巴细胞，而不是成肌细胞。 尽管GML的研究 最初专注于TSST 1，现在他们建议继续进行 在更广泛的基础上进行调查。 他们建议确定假定的 对GML敏感细菌中的信号传导途径 抑制，以确认信号转导是实际靶点， 并确定GML使用的假定信号通路， 刺激淋巴细胞。 PI希望这项工作能够全面了解 的结构、功能、遗传学、调节和病理生物学 TSST 1，将有助于开发某些诊断和治疗 应用加上针对超抗原的免疫的一般方法 毒素

DESCRIPTION (Adapted from the applicant's abstract): This is a competitive renewal of a collaborative project between the Novick and Schlievert laboratories aimed toward understanding the molecular genetics and pathobiology of one prototypical superantigen, toxic shock syndrome (TSST 1). Their results and the results of others suggest that the interaction of TSST 1 with the TCR and MHC Class II receptors is responsible for their superantigen activity. However, these investigators have provided evidence that its interaction with different types of receptors on other cells is responsible for its lethality. They have recently determined the structure of TSST 1 and several derivatives by X ray crystallography and have constructed a series of mutants with properties that have led to one hypothesis of this proposal, namely that lethality and superantigenicity are separately determined. The first two aims will focus on a definitive test of this hypothesis through confirmation of their preliminary results which suggest separable functions. This part of the project will investigate the pathobiology of TSST 1 by identifying and characterizing tissue specific receptors and determining the mechanism of intracellular cytotoxicity with reference to activities of mutant forms of the toxin. Aims 3 and 4 will be a continuing investigation into the molecular genetics of S. aureus toxin production. Aim 3 will focus on extending their preliminary genetic data suggesting that TSST 1 is encoded by a transposon, Tn557. This part of the project will determine the structure and function of Tn557 and also of closely linked heterologous insertions containing determinants of SEB and certain resistances. Aim 4 will attempt to develop an explanation for the mutual exclusion of TSST 1 positive and alpha-hemolysin positive phenotypes in S. aureus, despite the fact that many strains have both genes. A similar situation exists in group A streptococci with two superantigens (SPEA and SPEB). They have obtained preliminary results suggestive of an explicit regulatory antagonism between TSST 1 and alpha hemolysin. They propose to determine whether other exoproteins are involved and what is the basis of this antagonism. They will perform similar studies with SPEA and SPEB. Aim 5 will attempt to elucidate the mechanism of action for glycerol monolaurate effects on eukaryotic cells and on S. aureus. In a series of unrelated experiments, they have observed that GML inhibits the synthesis of TSST 1 and other exoproteins and also of the induction of resistance to several antibiotics, probably by interfering with signal transduction. Furthermore, they showed that GML is mitogenic for T lymphocytes but not for myoblasts. Although the study of GML was initially focused on TSST 1 they now propose to continue this investigation on a broader basis. They propose to identify the putative signal signalling pathway(s) in bacteria that are sensitive to GML inhibition, to confirm that signal transduction is the actual target, and to determine the putative signalling pathway used by GML to stimulate lymphocytes. The PI's expect that this work will lead to a comprehensive understanding of the structure function, genetics, regulation and pathobiology of TSST 1 and will help develop certain diagnostic and therapeutic applications plus a general method of immunization against superantigen toxins.