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病病例中涉及的两种主要病原体之一 传播生殖器感染。补体是先天免疫系统的一个重要方面， 对淋球菌感染的影响。我们实验室之前的工作表明，淋球菌的唾液酸化 脂寡糖（LOS）通过结合宿主补体调节导致补体抵抗 分子，H 因子。孔蛋白分子也结合 H 因子。在第一个特定目标中，我们将研究 H 因子的选择性剪接版本（称为 H 因子样分子 1 (FHL-1)）在结合 淋球菌和调节补体。淋病奈瑟菌的某些菌株会处理补体（即转化 将成分 3 [C3b] 补充为失活形式 [iC3b]）并结合 FHL-1，但不结合因子 H。 辅因子 FHL-1 的活性将使用仅含有 FHL-1 的血清进行评估，但不含有完整的 H 因子。因为两者 H 因子和 FHL-1 与细胞结合，我们将检查这两种分子在促进淋球菌感染中的作用 附着于永生化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，因子 H 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。波林 (Por) 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 两个物种之间的差异，以检查孔蛋白对唾液酸化 LOS 与因子 H 相互作用的影响 两个奈瑟氏菌物种的基线不同。其次，我们要考察功能性的决定因素。 LOS 唾液酸转移酶（脑膜炎球菌和淋球菌中的 ISO 酶）的特异性，通过执行等位基因 两个物种之间 I 基因的交换。第三，我们还将确定为什么效率 LOS 唾液酸化在血清敏感型（高唾液酸摄取）和“稳定”血清抗性（低唾液酸摄取）之间存在差异。 唾液酸摄取）淋球菌。这将通过检查 3H 标记的 CMP-NANA 的吸收来进行 同基因淋球菌仅在 Lst 酶方面有所不同。 Por 修改 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 合并者。在第三个具体目标中，我们将详细介绍 C4 和 C4 之间的连接（酰胺与酯） LOS、LOS 的己糖延伸对 C4 与 LOS 结合的影响以及键的影响 C4和LOS之间形成的杀菌剂。