MOLECULAR BIOLOGY OF TSST-1 & OTHER SUPERANTIGEN TOXINS

描述(改编自申请人的摘要)：这是一份 诺维克和诺维克之间合作项目的竞争性续签 施利弗特实验室致力于了解分子遗传学 以及一种典型超抗原中毒性休克综合征的病理生物学 (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 对它们的超抗原活性负责。然而，这些 调查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的结构和几个 通过X射线结晶学的衍生物，并构建了一系列 具有导致这一提议的一个假设的属性的突变体， 即致死性和超抗原性是分开确定的。 前两个目标将集中在对这一假设的最终检验上。 通过确认他们的初步结果，这表明 可分函数。该项目的这一部分将调查 TSST-1的组织特异性鉴定及病理生物学研究 受体与细胞内细胞毒作用机制的确定 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 金黄色葡萄球菌毒素产生的遗传学。目标3将专注于扩展 他们的初步遗传数据表明，TSST 1由一种 转座子，Tn557。该项目的这一部分将决定 Tn557及其紧密连锁异源基因的结构和功能 含有SEB决定因素和某些阻力的插入物。 目标4将试图提出一个解释，解释为什么 金黄色葡萄球菌TSST-1阳性和α-溶血素阳性表型 尽管许多菌株同时具有这两种基因。类似的情况 A组链球菌中存在两种超抗原(SPEA和SPEB)。 他们已经获得了初步的结果，表明 TSST-1和α-溶血素之间的调节拮抗作用。他们提议 以确定是否有其他外源蛋白参与，以及 这是这种对立的基础。他们将对SPEA进行类似的研究 和SPEB。 目标5将试图阐明甘油的作用机制 月桂酸酯对真核细胞和金黄色葡萄球菌的作用。在一系列中 在无关的实验中，他们观察到GML抑制了 TSST-1等外源蛋白的合成及其诱导 对几种抗生素的抗药性，可能是通过干扰信号 转导。此外，他们还表明GML对T细胞有丝分裂作用。 淋巴细胞，但不是成肌细胞。尽管对GML的研究是 他们最初专注于TSST 1，现在提议继续这样做 在更广泛的基础上进行调查。他们建议确定推定的 耐药细菌的信号转导途径(S) 抑制，以确认信号转导是真正的目标， 并确定GML使用的假定信号通路以 刺激淋巴细胞。 国际刑警组织预计，这项工作将导致对 的结构、功能、遗传学、调节和病理生物学 TSST 1，并将有助于开发某些诊断和治疗 应用外加超抗原免疫的一般方法 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.