Functional analysis of a Group A streptococcal locus important for fitness in soft tissue

对软组织健康很重要的 A 组链球菌基因座的功能分析

• 批准号: 9752160
• 负责人: Rezia Era Braza
• 金额: $ 3.71万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9752160
• 关键词: Architecture; Aromatic Amino Acids; Attenuated; Blood; Cells; Cessation of life; Computer Simulation; Development; Disease; Environment; Firmicutes; Functional disorder; Genes; Genetic; Genetic Transcription; Genome; Growth; Health; Human; Immune Evasion; Immune response; Impetigo; Infection; Invaded; Lead; Life; Membrane Proteins; Metabolic Pathway; Modeling; Mucous Membrane; Mus; Necrotizing fasciitis; Nutrient; Open Reading Frames; Operon; Oropharyngeal; Pathogenesis; Pathway interactions; Pharyngeal structure; Pharyngitis; Phenotype; Play; Proteins; Regulation; Role; Site; Skin; Soft Tissue Infections; Sterility; Streptococcal Infections; Streptococcus pyogenes; Stress; Tissues; Toxic Shock Syndrome; Validation; Virulence; base; clinically relevant; fitness; genetic architecture; human pathogen; in vivo; mouse model; mutant; novel therapeutics; pathogen; soft tissue; subcutaneous; therapeutic development; transposon sequencing

PROJECT SUMMARY A pathogen’s ability to adapt to different environments is an important factor in its survival, infection, and persistence within its host. As a strict human pathogen, Streptococcus pyogenes (Group A Streptococcus, GAS) causes over 500,000 deaths annually. Even though it commonly manifests as superficial infections (e.g. strep throat), GAS also causes life-threatening diseases (e.g. necrotizing fasciitis, toxic shock syndrome) when it invades normally sterile tissues from initial sites of infection. It is imperative to gain a better understanding of GAS pathophysiology and the genetic requirements it needs to infect varying host environments. Our lab performed an in vivo transposon sequencing (Tn-seq) screen in a clinically relevant M1T1 5448 GAS strain to define the genetic requirements needed for GAS fitness in the subepithelial tissue, where we found a previously uncharacterized locus (scfCDE) to be essential for this environment. Based on homology alone, scfCDE are predicted to encode for a putative ABC importer. Because the locus has not been experimentally examined before, this proposal will explore the functional roles of scfCDE in GAS cellular pathways and virulence, hypothesizing that scfCDE encode membrane-associated proteins that play integral roles in GAS fitness in host tissue, importing a substrate into the cell important for GAS pathophysiology. This study will examine the scfCDE locus for phenotypes in nutrient utilization and in stress-induced environments to identify potential substrates these proteins may transport, explore its genetic architecture, expression, and regulation of the operon, and lastly, explore whether scfCDE are important for colonization, growth in human blood, and innate immune evasion using established in vivo and ex vivo models of GAS infection. Since scfCDE are conserved in GAS and other Firmicutes, successful completion of this project will potentially contribute to the development of novel therapeutic strategies against GAS and other important Gram+ pathogens.

项目摘要 病原体适应不同环境的能力是其生存，感染， 并在其主机中的持久性。作为严格的人类病原体，化脓性链球菌（A组） 链球菌，气体）每年造成超过500,000人死亡。即使它通常表现为 浅表感染（例如链球菌性喉咙），气体还会引起威胁生命的疾病（例如坏死 筋膜炎，毒性休克综合征）当它从初始感染部位侵入正常无菌时机时。它 必须更好地了解气体病理生理学及其遗传要求 需要感染不同的主机环境。我们的实验室进行了体内转座子测序（TN-Seq） 在临床上相关的M1T1 5448气体应变中的屏幕以定义气体所需的遗传要求 下层组织中的适应性，我们发现先前未表征的基因座（SCFCDE）为 对于这个环境至关重要。仅基于同源性，预计SCFCDE将编码为推定的 ABC进口商。由于该基因座之前尚未进行过实验检查，因此该提案将探索 SCFCDE在气体细胞途径和病毒中的功能作用，假设SCFCDE编码 膜相关的蛋白质在宿主组织中起着气体适应性不可或缺的作用，进口底物 进入对气体生理学重要的细胞。这项研究将检查SCFCDE基因座 营养利用和应力引起的环境中的表型，以识别潜在的底物 这些蛋白质可以运输，探索其遗传结构，表达和调节， 最后，探索SCFCDE对于殖民化，人类血液的生长和先天而重要 使用已建立的体内和体内气体感染模型的免疫进化。因为SCFCDE是 在天然气和其他公司中保守，该项目的成功完成将有可能做出贡献 开发针对天然气和其他重要革兰氏病原体的新型治疗策略。