Determining the mechanisms by which YesMN drives pneumococcal host-to-host transmission

确定 YesMN 驱动肺炎球菌主机间传播的机制

• 批准号: 10041178
• 负责人: Muhammad Ammar Zafar
• 金额: $ 23.25万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-10 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10041178
• 关键词: Accounting; Address; Affect; Animal Model; Antibiotic Resistance; Bacterial Infections; Biological; Candidate Disease Gene; Cessation of life; Child; Clinical; Communicable Diseases; Complication; Data; Disease; Disease susceptibility; Elderly; Environment; Event; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Goals; Growth; Homeostasis; Human; Immune; In Vitro; Infant; Infection; Inflammatory Response; Influenza A virus; Intervention; Knowledge; Life Cycle Stages; Mediating; Metals; Micronutrients; Modeling; Modification; Morbidity - disease rate; Mucous Membrane; Muramidase; Nasopharynx; Onset of illness; Pathogenesis; Play; Pneumococcal Infections; Pneumococcal Pneumonia; Pneumococcal conjugate vaccine; Proliferating; Regulation; Regulon; Respiratory System; Respiratory Tract Infections; Role; Sampling; Signal Transduction; Stimulus; Streptococcus pneumoniae; Surface; System; Testing; Time; Transcription Alteration; Upper respiratory tract; Virus Diseases; Zinc; Zinc deficiency; antimicrobial; burden of illness; co-infection; epidemiologic data; epidemiology study; fitness; follow-up; high risk; host colonization; human pathogen; immune system function; in vitro Assay; in vivo; insight; knockout gene; member; mortality; mouse model; mutant; novel; novel therapeutics; novel vaccines; pathogen; prevent; public health relevance; respiratory; response; transcriptome; transcriptome sequencing; transmission process

Description. Streptococcus pneumoniae (Spn, the pneumococcus), a gram-positive human pathogen, is a significant cause of morbidity and mortality worldwide. Pneumococcus causes more deaths than any other infectious disease, with children and the elderly at the highest risk. Epidemiological data suggest host-to-host transmission of Spn is the critical first step required for both the carrier- and the disease-state, suggesting that it is imperative to block host-to-host events. However, because of the inherent complexities in studying natural transmission and the absence of tractable animal models, Spn transmission is one of the least understood aspects of this pathogen's lifecycle. We developed a tractable infant mouse model that has allowed for the identification of host and bacterial factors that contribute towards the transmission process. More recently, we screened random pools of transposon mutants (Tn-seq) and identified novel Spn genes whose products are involved in host-to-host transmission. This list of Spn transmission factors included YesMN, a poorly defined two-component system (TCS). Generally, TCS mediate rapid transcriptional changes in response to external stimuli. Hence, our focus in this proposal is the TCS YesMN. We premise that within the upper respiratory (URT), pneumococcus undergoes transcriptional alterations facilitated by YesMN that sense the host environment and respond accordingly, allowing for Spn persistence and enable it to transit from one host to another. We identified the putative regulon of YesMN through an in vitro RNA-seq screen, which included genes involved in zinc (Zn) homeostasis. Thus, in Aim #1, we will follow up on these putative regulon members and determine their contribution to the transmission process. We will also test whether Zn, a highly regulated metal by the host, acts as a signal for YesMN. As pneumococcal pneumonia is considered a clinical complication of influenza A virus (IAV) infection, we further tested whether YesMN affects Spn fitness under the Spn-IAV coinfection setting. We observed that with a concurrent IAV infection, Spn modifies its transcriptome, with a significant contribution from YesMN, which provides a fitness advantage in the URT. By taking a separate approach in Aim #2, we will carry out a novel in vivo RNA-seq screen on samples obtained from the URT and determine YesMN regulated genes that are potentially involved in providing fitness to Spn under these dynamic coinfection conditions. Results from our current studies would, for the first time, provide an understanding of the Spn transcriptional dynamics occurring in the URT that promote host-to-host transmission and whether the identified factors could be potential targets to reduce pneumococcal disease burden.

描述。 肺炎链球菌（SPN，肺炎球菌）是一种革兰氏阳性人类病原体，是一个重要原因 全球发病和死亡率。肺炎球菌比任何其他传染病都会导致更多的死亡， 儿童和老年人的风险最高。流行病学数据表明宿主传播传播 SPN是载体和疾病状态所需的关键第一步，这表明它是 必须阻止主机到主机事件。但是，由于研究自然的固有复杂性 SPN传播是传播和缺乏可拖动动物模型的传播 病原体生命周期的各个方面。我们开发了一种可拖动的婴儿小鼠模型，该模型允许 识别有助于传输过程的宿主和细菌因子。最近，我们 筛选的转座子突变体（TN-SEQ）的随机池，并鉴定 参与主机到主机传输。 SPN传输因子列表包括Yesmn，一个定义不佳 两个组件系统（TCS）。通常，TCS介导了对外部的快速转录变化 刺激。因此，我们在此提案上的重点是TCS YESMN。我们前提是在上呼吸道内 （urt），肺炎球菌经历了Yesmn促进的转录变化，感知宿主 环境并做出相应的回应，允许SPN持久性，并使其能够从一个主机过渡到 其他。我们通过体外RNA-seq屏幕确定了Yesmn的推定调节，其中包括 涉及锌（Zn）稳态的基因。因此，在AIM＃1中，我们将跟进这些推定的规范 成员并确定他们对传输过程的贡献。我们还将测试Zn是否高度 由宿主调节金属，充当YesMN的信号。由于肺炎球菌肺炎被认为是临床 流感病毒（IAV）感染的并发症，我们进一步测试了YESMN是否影响SPN适应性 SPN-IAV共感染设置。我们观察到，通过同时发生的IAV感染，SPN修改了其 转录组，具有YESMN的重大贡献，在URT中提供了健身优势。经过 在AIM＃2中采用单独的方法，我们将在获得的样品上进行体内RNA-seq屏幕的小说 从URT并确定可能参与提供适应性的YESMN调节基因 在这些动态共感染条件下为SPN。我们目前研究的结果将首次 提供对URT中发生的SPN转录动态的理解，以促进宿主至宿主 传播以及确定的因素是否可能是减少肺炎球菌疾病的潜在靶标 负担。