Immunology of Infection with Neisseria gonorrhoeae

淋病奈瑟菌感染的免疫学

• 批准号: 8043781
• 负责人: Peter A. Rice
• 金额: $ 8.35万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-05 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8043781
• 关键词: Address; Amides; Asialoglycoprotein Receptor; Bacteria; Binding; C3bi; Cells; Cervical; Chemicals; Clinical; Complement; Complement 3; Complement 3b; Complement 4b; Complement Factor H; Cytidine Monophosphate N-Acetylneuraminic Acid; Data; Disease; Enzymes; Epithelial Cells; Esters; Exhibits; Galactose; Genes; Genital system; Gonorrhea; Hexoses; Immune system; Immunology; Infection; Knowledge; Label; Laboratories; Length; Light; Link; Macrophage-1 Antigen; Mediating; Neisseria; Neisseria gonorrhoeae; Neisseria meningitidis; Pathogenesis; Pathway interactions; Process; RNA Splicing; Regulation; Relative (related person); Research Personnel; Resistance; Rice; Role; Serum; Sialic Acids; Sialyltransferases; Side; Specificity; Structure; Surface; Urethra; Variant; Work; bactericide; base; cofactor; enhancing factor; genital infection; killings; lacto-N-neotetraose; lipooligosaccharide; mimicry; pathogen; porin; programs; receptor; sialylation; uptake

Neisseria gonorrhoeae is one of the two major pathogens involved in the majority of cases of sexually transmitted genital infection. Complement forms an important aspect of the innate immune system that impacts upon gonococcal infection. Prior work in our laboratory has shown that sialylation of gonococcal lipooligosaccharide (LOS) results in complement resistance by binding the host complement regulatory molecule, factor H. The porin molecule also binds factor H. In the first Specific Aim, we will investigate the role of an alternatively-spliced version of factor H, called factor H-like molecule 1 (FHL-1)in binding to gonococci and in regulating complement. Some strains of N. gonorrhoeae process complement (i.e. convert complement component-3 [C3b] to the inactivated form [iC3b]) and bind FHL-1, but not factor H. Cofactor activity of FHL-1 will be assessed using serum containing only FHL-1, but not intact factor H. Because both factor H and FHL-1 bind to cells, we will examine the roles of these two molecules in facilitating gonococcal attachment to immortalized cervical and urethral epithelial cells, in the second Specific Aim, three questions that pertain to LOS sialylation will be addressed. First, the specificity of factor H binding to gonococcal lacto- N-neotetraose (LNT) sialic acid, but not to meningococcai LNT sialic acid, will be examined. Porin (Por) influences binding of fH to gonococcal sialic acid. We will perform allelic exchange of porin molecules between the two species to examine the effect of porin on the sialylated LOS interactions with factor H that differs at baseline in the two neisserial species. Second, we will examine the determinants of the functional specificity of the LOS sialyltransferase (IsO enzyme in meningococci and gonococci by performing allelic exchanges of the Ist genes between the two species. Third, we will also determine why the efficiency of LOS sialylation differs between serum-sensitive (high sialic acid uptake) and "stably" serum-resistant (low sialic acid uptake) gonococci. This will be performed by examining the uptake of 3H-labeled CMP-NANA by isogenic gonococci differing only in their Lst enzymes. The possibility that Por modifies Lst activity will also be examined by performing allelic exchanges of the Por genes between high and low sialic acid incorporators. In the third Specific Aim, we will detail the linkages (amide versus ester) between C4 and LOS, the effects of hexose extension of the LOS on binding of C4 to LOS, and the impact of the bond formed between C4 and LOS on bactericidal killing.

淋病奈瑟菌是大多数性传播疾病中的两种主要病原体之一， 生殖器感染补体形成先天免疫系统的一个重要方面， 对淋球菌感染的影响。我们实验室先前的工作表明，淋球菌的唾液酸化 脂寡糖（LOS）通过结合宿主补体调节因子而导致补体抗性。 分子，H因子。孔蛋白分子也结合H因子。在第一个具体目标中，我们将研究 因子H的选择性剪接形式，称为因子H样分子1（FHL-1）在结合 淋球菌和调节补体。部分N.淋病过程补充（即转化 补体成分-3（C3 b）转化为灭活形式（iC 3b），并结合FHL-1，但不结合H因子。辅因子 使用仅含FHL-1而不含完整因子H的血清评估FHL-1的活性。因为两 因子H和FHL-1结合细胞，我们将研究这两种分子在促进淋球菌感染中的作用。 附着于永生化的宫颈和尿道上皮细胞，在第二个具体目标中，三个问题 与LOS唾液酸化有关的问题将得到解决。首先，H因子与淋球菌乳糖结合的特异性， 将检查N-新四糖（LNT）唾液酸，但不检查脑膜炎球菌LNT唾液酸。孔蛋白 影响fH与淋球菌唾液酸的结合。我们将进行孔蛋白分子的等位基因交换 在两个物种之间检测孔蛋白对唾液酸化LOS与因子H相互作用的影响， 两种奈瑟球菌的基线不同。其次，我们将研究函数的决定因素 通过进行等位基因分析，在脑膜炎球菌和淋球菌中LOS唾液酸转移酶（IsO酶）的特异性 两个物种之间的Ist基因交换。第三，我们还将确定为什么 LOS唾液酸化在血清敏感（高唾液酸摄取）和“稳定”血清抗性（低唾液酸摄取）之间是不同的。 唾液酸摄取）淋球菌。这将通过检查3 H标记的CMP-NANA的摄取来进行， 仅在Lst酶方面不同的同基因淋球菌。Por改变Lst活性的可能性也将 通过在高唾液酸和低唾液酸之间进行Por基因的等位基因交换来检查 冰箱。在第三个具体目标中，我们将详细介绍C4和C5之间的连接（酰胺与酯）。 LOS，LOS的己糖延伸对C4与LOS结合的影响，以及结合的影响。 C4和LOS之间的杀菌作用。