SALIVARY IMMUNE RESPONSE TO COMMENSAL ORAL BACTERIA

对口腔共生细菌的唾液免疫反应

• 批准号: 3221957
• 负责人: MICHAEL F. COLE
• 金额: $ 18.81万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-12-01 至 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3221957
• 关键词: SDS polyacrylamide gel electrophoresis; Streptococcus mitis; Streptococcus mutans; antibacterial antibody; antibody specificity; bactericidal immunity; blood; endopeptidases; enzyme linked immunosorbent assay; genetic strain; genotype; host organism interaction; human milk; human subject; humoral immunity; immunoglobulin A; immunoregulation; infant human (0-1 year); longitudinal human study; microorganism culture; oral bacteria; preschool child (1-5); restriction fragment length polymorphism; saliva; secretory immune system; western blottings

At birth pioneer bacterial colonize the mouth and are succeeded by other populations to form the normal flora which plays an important role in host defense by excluding exogenous pathogens. However, dental caries and periodontal disease, are caused by bacteria that are often isolated from the normal flora. Furthermore, some commensal bacteria are opportunistic pathogens that cause severe systemic disease when the immune system is compromised. Secretory immunoglobulin A (SigA) antibodies reactive with commensal bacteria are present in saliva but their impact ont he normal flora is not known. the objective of this competing continuation is to define the salivary immune response to commensal oral bacteria and studies will focus on the pioneer bacterium S. mitis biovar 1, and the late colonizer S. mutans, for the following reasons: (1) pioneer bacteria are the first to colonize the mucosal surfaces and to be exposed to the secretory immune system; (2) pioneer bacteria are exclusively streptococci of limited phenotype; (3) S. mitis biovar 1 is the principal pioneer Streptococcus; (4) the immune response to the "late" colonizing streptococcus S. mutans, which is exposed to a more developed secretory immune system, can be compared to the early response to the pioneer S. mitis biovar 1. Saliva, breast milk, cord blood, serum and isolates of S. mitis biovar 1 and S. mutans obtained from the infant-mother pairs during an ongoing longitudinal study and its extension to the third year of the infants' life will be analyzed to test the following hypothesis: Commensal bacteria colonize and persist in the mouth because they subvert SigA antibodies and/or because secretory antibodies are of low avidity, low level or the wrong specificities. The Specific Aims are as follows: Aim 1: Determine the incidence of pioneer viridans streptococci producing IgA1 protease. Isolates of pioneer streptococci will be incubated with IgA1 and IgA1 protease activity will be detected by SDS-PAGE to test the hypothesis that IgA1 protease is an ecological determinant in colonization by destroying the biological activity of SigA1 antibodies. Aim 2: Analyze the clonal diversity of S. mitis biovar 1 and S. mutans. Isolates of these streptococci obtained from the infant-mother pairs during the ongoing longitudinal study will be examined by DNA fingerprinting and ribotyping to test the hypotheses that: (a) there is limited genetic heterogeneity within the strains of these species in each infants mouth; (b) different infants harbor different genotypes of these species; (c) clonotypes of these species are stable in the mouth over time; (d) an infant acquires these bacteria from the mother. Aim 3: Analyze the diversity of secretory and systemic antibodies reactive with S. mitis biovar 1 and S. mutans. Saliva, breast milk, cord blood and serum obtained from the infant-mother pairs will be analyzed by Western blotting and by ELISA to test the hypotheses that: (a) antibodies reactive with S. mitis biovar 1 and S. mutans are composed of (1) cross-reactive antibodies induced by related oral and/or gut bacteria and (2) specific antibodies induced by colonization of the homologous strain; (b) antibody specificities differ in the secretory and systemic compartments of the humoral immune system. Aim 4: Analyze the avidity of SigA, SigA1, and SigA2 antibodies reactive with S. mitis biovar 1 and S. mutans. Chaotrope dissociation ELISA and immunoblots will be used to test the hypothesis that commensal bacteria induce low avidity SigA antibodies that do not exhibit affinity maturation and are ineffective in immune elimination of these bacteria.

出生时，先锋细菌在口腔中定植，并被其他细菌继承 种群形成正常菌群，在 通过排除外源病原体来防御宿主。 然而，龋齿 和牙周病，是由通常分离的细菌引起的 来自正常菌群。 此外，一些共生细菌是 机会致病菌在感染时会引起严重的全身性疾病 免疫系统受到损害。 分泌型免疫球蛋白 A (SigA) 唾液中存在与共生细菌反应的抗体，但 它们对正常菌群的影响尚不清楚。 这样做的目的 竞争性的延续是定义唾液免疫反应 共生口腔细菌和研究将集中于先锋细菌 S. mitis biovar 1 和晚期殖民者 S. mutans，用于以下目的 原因：（1）先锋菌最先定植于粘膜 表面并暴露于分泌性免疫系统； (2)先锋 细菌仅是有限表型的链球菌； (3) 轻链霉菌 biovar 1 是主要先驱链球菌； (4)免疫反应 到“晚期”定植的链球菌变形链球菌，该链球菌暴露于 与早期相比，分泌性免疫系统更加发达 对先驱 S. mitis 生物变种的反应 1. 唾液、母乳、脐带 获得 S. mitis biovar 1 和 S. mutans 的血液、血清和分离株 来自正在进行的纵向研究中的婴儿-母亲对及其 延长至婴儿生命第三年将进行分析测试 以下假设：共生细菌定殖并持续存在于 因为它们破坏了 SigA 抗体和/或因为分泌 抗体亲和力低、水平低或特异性错误。 这 具体目标如下： 目标 1：确定先驱者的发生率 草绿色链球菌产生 IgA1 蛋白酶。 先锋隔离物 链球菌将与 IgA1 一起孵育，并且 IgA1 蛋白酶活性将 通过 SDS-PAGE 检测以检验 IgA1 蛋白酶是一种假设 通过破坏生物来进行殖民化的生态决定因素 SigA1 抗体的活性。 目标 2：分析克隆多样性 S. mitis biovar 1 和 S. mutans。 获得这些链球菌的分离物 在正在进行的纵向研究期间，来自婴儿-母亲对的数据将 通过 DNA 指纹分析和核糖分型进行检查以检验假设 (a) 菌株内的遗传异质性有限 每个婴儿嘴里都有这些物种； (b) 不同的婴儿港 这些物种的不同基因型； (c) 这些物种的克隆型是 随着时间的推移在口腔中保持稳定； (d) 婴儿从以下来源获得这些细菌 母亲。 目标 3：分析分泌性和系统性的多样性 与 S. mitis biovar 1 和 S. mutans 反应的抗体。 唾液、乳房 从母婴对获得的乳汁、脐带血和血清将被 通过蛋白质印迹和 ELISA 进行分析，以检验以下假设： (a) 与 S. mitis biovar 1 和 S. mutans 反应的抗体的组成 (1) 相关口腔和/或肠道诱导的交叉反应抗体 细菌和（2）定植诱导的特异性抗体 同源菌株； (b) 抗体特异性在分泌和 体液免疫系统的全身区室。 目标 4：分析 与轻链球菌反应的 SigA、SigA1 和 SigA2 抗体的亲和力 biovar 1 和 S. mutans。 离液剂解离 ELISA 和免疫印迹 将用于检验共生细菌诱导低水平的假设 亲和力 SigA 抗体不表现出亲和力成熟，并且是 对这些细菌的免疫消除无效。