Group B. Streptococci and Toll-like Receptors

B 组链球菌和 Toll 样受体

• 批准号: 6647192
• 负责人: Douglas T Golenbock
• 金额: $ 40.48万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6647192
• 关键词: SDS polyacrylamide gel electrophoresis; Streptococcus agalactiae; Streptococcus infection; bacteria infection mechanism; bacterial toxins; binding sites; biological signal transduction; cell line; chemotaxis; flow cytometry; gene deletion mutation; gene targeting; genetically modified animals; host organism interaction; laboratory mouse; leukocyte activation /transformation; molecular cloning; nuclear factor kappa beta; nucleic acid sequence; protein protein interaction; protein structure function; receptor binding; receptor expression; site directed mutagenesis; toll like receptor; transfection /expression vector

DESCRIPTION (provided by applicant): Group B streptococci (GBS) are the leading cause of neonatal sepsis, the third most frequent cause of bacterial meningitis and an increasingly important cause of bacteremia and sepsis in adults in the United States today. Preliminary studies have identified a novel proinflammatory component of GBS, which we have designated GBS-factor (GBS-F). Based on experiments in mice with targeted genetic deletions in Toll-like receptor (TLR) expression and on experiments with engineered cell lines, we have determined that responses to GBS-F require expression of CD14, TLRs 2 and 6, and the Toll-adapter protein, MyD88. Activation of this receptor complex by GBS-F initiates important signaling events such as the activation of NF-kB, the phosphorylation of MAP kinases, the formation of proinflammatory cytokines, and the intracellular production of the toxic oxidant peroxynitrate. In contrast, although other components of GBS appear to engage TLRs, the exact identity of contributing TLRs is entirely unknown. The overall goal of this proposal is to identify and define components of GBS, focusing first on GBS-F, and their cognate Toll-like receptors (TLRs). We propose to characterize the structure of GBS-F and assess its function in vitro and in vivo. Furthermore, we will determine if TLR2, and related downstream signal transduction molecules, mediate a variety of important innate immune responses to GBS, including leukocyte chemotaxis and the intracellular killing of bacteria. Finally, we intend to determine what other TLRs, and associated signal transduction molecules, are involved in GBS recognition and response. The data learned from these studies should help in the development of rational therapeutic strategies to interfere with the deleterious hyperinflammation triggered by GBS and similar microbial organisms.

描述（由申请人提供）：B 族链球菌 (GBS) 是新生儿败血症的主要原因，是细菌性脑膜炎的第三大常见原因，也是当今美国成人菌血症和败血症的日益重要的原因。初步研究已经确定了 GBS 的一种新型促炎成分，我们将其命名为 GBS 因子 (GBS-F)。基于对 Toll 样受体 (TLR) 表达进行靶向基因缺失的小鼠进行的实验以及对工程细胞系进行的实验，我们确定对 GBS-F 的反应需要表达 CD14、TLR 2 和 6 以及 Toll 适配器蛋白质，MyD88。 GBS-F 激活该受体复合物会引发重要的信号转导事件，例如 NF-kB 的激活、MAP 激酶的磷酸化、促炎细胞因子的形成以及有毒氧化剂过氧硝酸盐的细胞内产生。相比之下，尽管 GBS 的其他成分似乎与 TLR 相关，但贡献 TLR 的确切身份却完全未知。该提案的总体目标是识别和定义 GBS 的组成部分，首先关注 GBS-F 及其同源 Toll 样受体 (TLR)。我们建议表征 GBS-F 的结构并评估其体外和体内功能。此外，我们将确定 TLR2 和相关下游信号转导分子是否介导针对 GBS 的各种重要的先天免疫反应，包括白细胞趋化性和细胞内细菌杀伤作用。最后，我们打算确定哪些其他 TLR 和相关信号转导分子参与 GBS 识别和响应。从这些研究中获得的数据应有助于制定合理的治疗策略，以干扰 GBS 和类似微生物引发的有害过度炎症。