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: 10186702
• 负责人: Muhammad Ammar Zafar
• 金额: $ 19.38万
• 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 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10186702
• 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，是导致肺炎的重要原因 全球发病率和死亡率。肺炎球菌导致的死亡人数比任何其他传染病都要多， 儿童和老年人的风险最高。流行病学数据表明存在宿主间传播 Spn 的检测是携带者和疾病状态所需的关键的第一步，表明它是 必须阻止主机到主机事件。然而，由于研究自然的固有复杂性 由于缺乏易驯化的动物模型，Spn 传播是最不为人所知的传播之一 该病原体生命周期的各个方面。我们开发了一种易于驯服的婴儿小鼠模型，该模型允许 识别有助于传播过程的宿主和细菌因素。最近，我们 筛选转座子突变体的随机池（Tn-seq）并鉴定出新的 Spn 基因，其产物为 参与主机到主机的传输。这个 Spn 传输因子列表包括 YesMN，一个定义不明确的 双组分系统（TCS）。一般来说，TCS 会介导快速转录变化以响应外部环境。 刺激。因此，我们本提案的重点是 TCS YesMN。我们假设在上呼吸道内 （URT），肺炎球菌经历由感知宿主的 YesMN 促进的转录改变 环境并做出相应响应，允许 Spn 持久性并使其能够从一台主机传输到 其他。我们通过体外 RNA-seq 筛选鉴定了 YesMN 的假定调节子，其中包括 参与锌（Zn）稳态的基因。因此，在目标#1中，我们将跟进这些假定的调节子 成员并确定他们对传输过程的贡献。我们还将测试锌是否是一种高度 由宿主调节的金属，充当 YesMN 的信号。由于肺炎球菌肺炎被认为是一种临床疾病 甲型流感病毒（IAV）感染的并发症，我们进一步测试了 YesMN 是否影响 Spn 健康度 Spn-IAV 共感染设置。我们观察到，在并发 IAV 感染的情况下，Spn 会改变其 转录组，YesMN 做出了重大贡献，它在 URT 中提供了适应性优势。经过 在目标 #2 中采取单独的方法，我们将对获得的样本进行新颖的体内 RNA-seq 筛选 从 URT 中确定 YesMN 调节的基因，这些基因可能参与提供健康 在这些动态共感染条件下形成 Spn。我们目前的研究结果将首次， 提供对 URT 中促进宿主到宿主的 Spn 转录动力学的理解 传播以及已确定的因素是否可以成为减少肺炎球菌疾病的潜在目标 负担。