Contribution of the peptidome to CA-MRSA virulence

肽组对 CA-MRSA 毒力的贡献

• 批准号: 10605180
• 负责人: David J Gonzalez
• 金额: $ 39.5万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-18 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10605180
• 关键词: Address; Area; Bacteria; Binding; Biochemical; Biological Assay; Biological Process; Biology; Cells; Communities; Complex; Cytolysins; Data; Development; Discipline; Disease; Environment; Epithelium; Etiology; Genome; Genomics; Genus staphylococcus; Health; Homologous Gene; Host Defense; Human; In Vitro; Infection; Infectious Skin Diseases; Keratin; Knowledge; Libraries; Lipoproteins; Mass Spectrum Analysis; Microbiology; Modeling; Molecular; Mus; Pathogenesis; Pathogenicity; Pathway interactions; Penetration; Peptides; Phenols; Play; Process; Proteins; Proteome; Proteomics; PubMed; Publishing; Regulator Genes; Research; Role; Serum; Staphylococcal Infections; Staphylococcus aureus; Structure; System; Targeted Toxins; Testing; Tissues; Transcript; Virulence; Virulence Factors; Work; cell type; human pathogen; in vivo; innovation; methicillin resistant Staphylococcus aureus; mortality; multiple omics; mutant; novel; novel therapeutics; pathogen; prohibitin; rational design; skin lesion; synthetic peptide

PROJECT SUMMARY A comprehensive understanding of bacterial pathogenesis not only requires a detailed knowledge of the genome and proteome, but also the peptidome elaborated during the progression of infection. The overall objective of this proposal is to build upon our exciting preliminary observations describing the identification of endogenous microproteins and peptides detected in cell-free supernatants of community-associated (CA) MRSA cultures. Within this group we identified two novel microproteins originating from an unannotated locus in the CA-MRSA TCH1516 genome. We found that these microproteins, termed S. aureus microprotein 1 (SAM1) and S. aureus microprotein 2 (SAM2), are highly conserved among Staphylococci and are regulated by the classical accessory gene regulatory system. We have started to characterize these factors, showing that SAM1 appears to act as a canonical cytolysin. Intriguingly, SAM2 possesses unique bioactivity, the perturbation of keratin networks that promotes an in vivo switch from a localized S. aureus skin infection to an invasive dissemination to the underlying tissues. The central hypothesis of this proposal is that SAMs significantly contribute to CA-MRSA’s ability to cause disease in a host. In Aim 1, we will dissect the pathogenic contributions of SAM1 as a functional cytolysin in vitro and in vivo. Given the bioactivity of SAM1 is inhibited by serum lipoproteins, we will focus on its role once CA-MRSA is in an intracellular environment. Our strong preliminary data suggests SAM1 selectively binds to prohibitins (PHBs) across differential host cell types. Thus, we will take the study of CA-MRSA cytolysins in a new direction by dissecting the potential role of PHBs as targets of SAM1. In Aim 2, we will perform a structure and function analysis of the interaction between SAM2 and keratin. Our data shows that this interaction has an important in vivo consequence during the shift from a local to invasive infection type. By a powerful combination of microbiology and multi-omic approaches, we will define the SAM2 structural contact points required for pathogenesis and will detail host pathways that are impacted by SAM2 during the invasive switch. In Aim 3, to assess the broader significance of our discovery, we will determine the pathogenic roles SAMs play in a diverse library of CA-MRSA strains, in addition to other Staphylococcal pathogens that express bioactive SAM homologs. Aim 3 is critical given that the importance of SAMs in other Staphylococci beyond CA-MRSA TCH1516 remains unknown. This proposal is highly innovative because it departs from the current focus of investigating host-pathogen interactions through the more established genomic and proteomic workflows. The proposed work is highly significant given it can drive the development of anti-Staphylococcal therapies based on a relatively new and largely mysterious molecular paradigm - the peptidome.

项目概要 全面了解细菌发病机制不仅需要详细了解 基因组和蛋白质组，还有感染过程中形成的肽组。 该提案的目的是建立在我们令人兴奋的初步观察的基础上，这些观察描述了 在群落相关 (CA) 的无细胞上清液中检测到内源微生物蛋白和肽 在该组 MRSA 培养物中，我们鉴定了两种源自未注释基因座的新型微生物蛋白。 我们在 CA-MRSA TCH1516 基因组中发现了这些微生物蛋白，称为金黄色葡萄球菌微生物蛋白 1。 (SAM1) 和金黄色葡萄球菌微蛋白 2 (SAM2) 在葡萄球菌中高度保守并受到调控 通过经典的辅助基因调控系统，我们已经开始描述这些因素，表明 SAM1 似乎是一种典型的溶细胞素，有趣的是，SAM2 具有独特的生物活性。 角蛋白网络的扰动促进体内从局部金黄色葡萄球菌皮肤感染转变为 该提案的中心假设是 SAM 的侵入性传播。 在目标 1 中，我们将剖析 CA-MRSA 在宿主中引起疾病​​的能力。 SAM1 作为功能性溶细胞素在体外和体内的致病贡献 SAM1 的生物活性是 由于 CA-MRSA 受到血清脂蛋白的抑制，一旦 CA-MRSA 进入细胞内环境，我们将重点关注其作用。 强有力的初步数据表明 SAM1 选择性地结合不同宿主细胞的抑制素 (PHB) 因此，我们将通过剖析 CA-MRSA 溶细胞素的潜在作用，将研究带向新的方向。 PHBs 作为 SAM1 的目标 在目标 2 中，我们将对相互作用进行结构和功能分析。 我们的数据表明，这种相互作用在体内具有重要的影响。 通过微生物学和多组学的强大结合，从局部感染类型转变为侵袭性感染类型。 方法，我们将定义发病机制所需的 SAM2 结构接触点，并详细说明宿主 在目标 3 中，评估 SAM2 在侵入性转换过程中影响的途径，以评估更广泛的意义。 根据我们的发现，我们将确定 SAM 在不同的 CA-MRSA 菌株库中发挥的致病作用， 鉴于此，除了表达生物活性 SAM 同源物的其他葡萄球菌病原体外，Aim 3 也至关重要。 SAM 在除 CA-MRSA TCH1516 之外的其他葡萄球菌中的重要性仍然未知。 具有高度创新性，因为它偏离了当前研究宿主与病原体相互作用的焦点 鉴于更成熟的基因组和蛋白质组工作流程，拟议的工作非常重要。 它可以推动基于相对较新且很大程度上神秘的抗葡萄球菌疗法的发展 分子范式——肽组。