SALIVARY IMMUNE RESPONSE TO COMMENSAL ORAL BACTERIA

对口腔共生细菌的唾液免疫反应

• 批准号: 2129982
• 负责人: MICHAEL F. COLE
• 金额: $ 19.3万
• 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/2129982
• 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.

出生先驱细菌在嘴巴上定居，并由其他人继承 种群形成正常菌群，在 通过排除外源性病原体来防御。 但是，龋齿 牙周疾病是由经常被分离的细菌引起的 来自普通菌群。 此外，一些共生细菌是 机会性病原体会导致严重的全身性疾病 免疫系统受到损害。 分泌免疫球蛋白A（SIGA） 唾液中存在与共生细菌反应性的抗体，但 他们的影响力是正常的菌群。 这个目的 竞争继续是定义唾液免疫反应 共生口服细菌和研究将重点放在先锋细菌上 S. mitis Biovar 1和已故的菌落菌S. mutans，以下 原因：（1）先锋细菌是第一个定居粘膜的细菌 表面并暴露于分泌免疫系统； （2）先驱 细菌仅是有限表型的链球菌。 （3）S。mitis Biovar 1是主要的先驱链球菌； （4）免疫反应 对“晚期”定植链球菌链球菌，该链球菌暴露于A 可以将更发达的分泌免疫系统与早期进行比较 对先驱S. Mitis Biovar 1.唾液，母乳，绳索的反应 获得的血液，血清和分离菌菌1和链球菌的分离株 在正在进行的纵向研究中，来自婴儿成对及其 将分析到婴儿生命的第三年以进行测试 以下假设：共生细菌定居并持续存在 嘴因为它们颠覆了Siga抗体和/或分泌物 抗体的高潮，低水平或错误的特异性。 这 具体目的如下：目标1：确定先锋的发生率 生产IgA1蛋白酶的Viridans链球菌。 先锋的分离物 链球菌将与IgA1一起孵育，IgA1蛋白酶活性将 可以通过SDS-PAGE检测到Iga1蛋白酶是一种假设 通过破坏生物学的生态决定因素 SIGA1抗体的活性。 目标2：分析克隆多样性 S. mitis Biovar 1和S. utans。 这些链球菌的分离株 在正在进行的纵向研究期间，从婴儿成对中 通过DNA指纹和结型来检查假设 那是：（a）在菌株中的遗传异质性有限 每个婴儿的口腔中的这些物种； （b）不同的婴儿港口 这些物种的不同基因型； （c）这些物种的插型是 随着时间的流逝，在嘴里稳定； （d）婴儿从 母亲。 目标3：分析分泌和系统的多样性 抗体用链球菌生物链球菌1和链球菌反应。 唾液，乳房 从婴儿对的牛奶，脐带血和血清将是 通过Western印迹和ELISA分析以检验： （a）抗体用链球菌生物链球菌1和链球菌反应作用 （1）相关口服和/或肠道诱导的交叉反应抗体 细菌和（2）通过定植的特异性抗体 同源菌株； （b）抗体特异性在分泌方面有所不同 体液免疫系统的全身室。 目标4：分析 SIGA，SIGA1和SIGA2抗体的亲发性与链球菌反应 Biovar 1和S. mutans。 混沌解离ELISA和免疫印迹 将使用共生细菌诱导低的假设 不表现出亲和力成熟并且是 在免疫消除这些细菌方面无效。