The Structural and Functional Determination of Streptococcus mutans Adherence

变形链球菌粘附的结构和功能测定

• 批准号: 10112889
• 负责人: Champion Christdoss Selvakumar Deivanayagam
• 金额: $ 42.24万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10112889
• 关键词: Acids; Address; Adherence; Adhesions; Adopted; Affect; Affinity; Animal Model; Bacterial Adhesins; Binding; Candida albicans; Child; Collagen; Complex; Comprehension; Coupled; Crystallization; Dental Models; Dental caries; Development; Dextrans; Ecology; Ensure; Etiology; Future; Gene Mutation; Genes; Glucans; Glucosyltransferases; Goals; Human; I-antigen; Individual; Investigation; Knowledge; Ligands; Maps; Mediating; Membrane Proteins; Methods; Microbe; Microbial Biofilms; Modeling; Molecular; Mutagenesis; Oral; Oral cavity; Outcome; Outcome Study; Pathogenesis; Pathogenicity; Peptides; Play; Population; Predisposition; Production; Protein C; Proteins; Rattus; Resolution; Rodent Model; Role; Salivary; Scavenger Receptor Cysteine-Rich Domain; Site; Streptococcus Viridans Group; Streptococcus adhesin; Streptococcus gordonii; Streptococcus mutans; Structure; Study models; Surface; Therapeutic; Virulence; combinatorial; comparative; dental biofilm; design; dysbiosis; early childhood; genetic manipulation; glucan-binding protein; glycoprotein 340; microbial; microbial colonization; microorganism; microorganism interaction; mutant; nanomolar; oral streptococci; pathogen; polymicrobial disease; prevent; sortase; tooth surface

Dental caries is a polymicrobial disease that affects much of the human population worldwide, where the harmony of a cooperative eco-organization shifts towards a dysbiotic framework with overrepresentation of pathogenic microorganisms, particularly by Streptococcus mutans (SM). For planktonic SM, adhesion to tooth surface and/or dental biofilms is a crucial step in the pathogenesis of dental caries, and SM has evolved (i) SM- host and (ii) SM-microbial interactions, which are mediated through its surface proteins (adhesins). SM’s adhesion mediated interactions include: (A) The recent discovery of redundant high affinity binding of SM’s adhesins to the scavenger receptor cysteine rich domains (SRCR) of the salivary glycoprotein 340 (Gp340), which promotes caries susceptibility in the SM-host interface; and (B) The revelation of SM’s adhesin required for the SM-Candida albicans (CA) biofilm formation and acid production, which enhances cariogenicity in early childhood caries in the SM-microbial interface. Together these have revealed previously unknown interactions by once thought to be well-known and well-characterized adhesins on SM. Yet the key unanswered question remains, “how does SM mediate such redundant, but specific binding to host proteins and to other microbes?” The goal of this application is to determine the specific motif(s) and/or molecular mechanism(s) that drive SM’s adherence, particularly how they enable binding to multiple ligands. Our structural and functional studies show that SM’s surface adhesins mediate these attachments primarily via two major structural domains, the V- and C-fold. We hypothesize that “the V- and C-fold present on the surface adhesins of SM mediate specific interactions through common binding motif(s) that are crucial for biofilm formation and microbial colonization”. We will address our hypothesis through three specific aims (SAs) by (a) mapping the adherence motif(s) on the V-fold (SA1) and (b) C-fold (SA2) of oral streptococcal adhesins, and (c) investigating the role of SM’s adhesins in the SM-Candida albicans (CA) interface (SA3). The results from this multi-PD/PI study will (i) Determine the binding-motif(s)/mechanisms globally adopted by the V- and C-fold among SM’s adhesins; (ii) Determine the presence of distinct and/or overlapping adherence sites for various ligands; (iii) Provide a comparative analysis of the V- and C-fold of various adhesins from mutans and viridans streptococci, revealing species-specific differences in their binding-motifs/mechanisms; (iv) Characterize the role of SM adhesins at the SM-CA interface; and (v) Elucidate alternations in the microbial ecology modulated by SM’s V- and C-folds, particularly as they relate to dental caries. Our proposed structural analyses, genetic manipulation of key adhesion motif(s) and animal model studies will determine the adherence mechanisms and address the knowledge gap on SM’s V- and C-fold, particularly their crucial role in promoting colonization and virulence. The results will enable future development of selective combinatorial therapeutics to prevent SM’s adherence to host and microbes.

龋齿是一种影响人口世界中许多世界的多数疾病， 合作生态组织的和谐转向了不陈述的失调框架 致病性微生物，特别是链球菌突变（SM）。对于浮游SM，对牙齿的粘附 表面和/或牙科生物膜是龋齿发病机理的关键步骤，SM已进化（i）Sm- 宿主和（ii）SM微生物相互作用，这些相互作用是通过其表面蛋白（粘附素）介导的。 SM的粘附介导的相互作用包括：（a）最近发现的冗余高亲和力结合 SM遵守唾液糖蛋白340（GP340）的清道夫受体富含半胱氨酸富域（SRCR）， 促进了SM-host界面中的汽车敏感性； （b）SM粘附素的开发 对于SM-Candida白色念珠菌（CA）生物膜的形成和酸的产生，可以提高富早期的致性性 Sm-Microbial界面中的儿童汽车。这些共同揭示了以前未知的互动 一旦被认为是SM上的知名且特征良好的粘附力。然而，关键的未解决的问题 仍然存在：“ SM如何介导如此多余的，但对宿主蛋白和其他微生物的特定结合？” 该应用的目的是确定驱动驱动的特定基序和/或分子机制 SM的依从性，尤其是它们如何与多种配体结合。我们的结构和功能研究 表明SM的表面粘附通过两个主要结构域介导了这些附件，即V- 和C折。我们假设“ SM的表面粘附在介导的特定表面上存在的V-和C倍 通过共同结合基序相互作用，对于生物膜形成和微生物定植至关重要。” 我们将通过（a）映射依从性图案（s）通过三个特定目标（SA）来解决我们的假设。 口服链球菌粘附素的V折（SA1）和（B）C折（SA2），以及（c）研究SM的粘附素的作用 在Sm-Candida白色疾病（CA）界面（SA3）中。 这项多PD/PI研究的结果将（i）确定全球采用的结合态度/机制 在SM的依从性中，V-和C折； （ii）确定存在明显和/或重叠依从性的存在 各种配体的位置； （iii）对突变的各种粘合剂的V-和c折的比较分析 和Viridans链球菌，揭示其结合摩托图/机制的特定规格差异； （iv） 表征SM粘附在SM-CA界面上的作用； （v）阐明微生物中的替代方案 生态学由SM的V-和C折调节，尤其是与龋齿有关的生态学。 我们提出的结构分析，关键广告图案的基因操纵和动物模型研究 将确定依从性机制，并解决有关SM的V-和C折的知识差距，尤其是 它们在促进定植和病毒中的关键作用。结果将使未来的选择性发展 组合疗法以防止SM遵守宿主和微生物。