CD8+ tissue-resident immunity to primary and heterotypic Influenza A controlled by commensal microbiota

项目摘要/摘要 在病毒性肺炎的所有年龄段中，新生儿的感染相关死亡率最高。 每年造成这些估计100万人死亡的人中的大多数。世界上大多数的新生儿 新生儿重症监护病房(NICU)接受经验性抗生素治疗。这种抗生素的暴露 失调免疫的发展，包括流感特异性CD8+T细胞，尽管 早期接触抗生素究竟如何影响组织驻留的形成和功能 CD8+T细胞尚不清楚。凭借其作为病毒感染适应性应答器的典型作用，CD8+ T细胞是关键的效应者免疫细胞，在宿主的即刻和长期防御中都是如此 严重的病毒性肺炎。更好地定义早期接触抗生素的确切方式是至关重要的 扰乱组织驻留的CD8+T细胞的形成和功能，以减少实质性 新生儿肺炎相关死亡率。该提案中的初步流式细胞仪数据显示 早期接触抗生素会减少流感特异性CD8+T细胞的形成， 导致更高的病毒负担和发病率。初步的单细胞RNA(scRNA-)和单细胞 转座酶可及染色质测序分析(ScATACseq)数据显示类似 肺CD8+T细胞减少，这是由基因调控网络中的特定变化控制的。 这一数据推动了这一提议的总体假设，即早期接触抗生素 导致组织驻留的CD8+T细胞的形成和功能减少 甲型流感既有原发感染也有异型感染。这项提议将通过以下方式检验这一假设 早期接触抗生素对CD8+T细胞形成和功能的影响 甲型流感攻击后肺内的细胞(目标1)和确定调节 早期抗生素暴露如何影响CD8+T细胞功能的机制 (目标2)。总而言之，这项工作将为早期生命中的抗生素提供新的、机械性的见解 暴露正在影响流感特异性组织驻留CD8+T细胞的功能。这些目标 预计将显示抗生素介导的CD8+T细胞杀伤力、细胞因子产生、 和增殖，以及潜在的特定基因调控网络的变化 功能失调。推动这项提议的候选人目前是一名医学博士/博士生 辛辛那提儿童医院在希特什·德什穆克博士的实验室里，他将使用这项提议 为作为一名内科科学家的独立职业生涯奠定基础。候选人将使用这个 建议支持他作为儿科加强治疗师在诊所的未来，从这个发现 该提案将揭示新的战略，为最脆弱的新生儿带来更好的结果。

Project Summary/Abstract Neonates have the highest infection-related mortality of any age group with viral pneumonia causing the majority of these estimated 1 million deaths per year. A majority of neonates in the neonatal intensive care unit (NICU) receive empiric antibiotic therapy. This antibiotic exposure dysregulates the development of immunity, including influenza-specific CD8+ T cells, although exactly how early-life antibiotic exposure affects the formation and function of tissue-resident CD8+ T cells is unclear. With their canonical role as adaptive responders to viral infection, CD8+ T cells are key effector immune cells in both immediate and long-term host defense against serious viral pneumonia. It is essential to better define how exactly early-life antibiotic exposure disrupts tissue-resident CD8+ T cell formation and function in order to lessen the substantial pneumonia-related mortality in neonates. Preliminary flow cytometry data in this proposal shows that early-life antibiotic exposure reduces the formation of influenza-specific CD8+ T cells, which leads to higher viral burden and morbidity. Preliminary single cell RNA (scRNA-) and single cell Assay for Transposase-accessible Chromatin sequencing (scATACseq) data shows a similar reduction in lung CD8+ T cells that is controlled by specific alterations in gene regulatory networks. This data drives the overall hypothesis of this proposal that early-life antibiotic exposure leads to a decrease in the formation and functions of tissue-resident CD8+ T cells following both primary and heterotypic Influenza A infection. This proposal will test this hypothesis by determining the effect of early-life antibiotic exposure on the formation and function of CD8+ T cells in the lungs following challenge with Influenza A (Aim 1) and determining regulatory mechanisms governing how this early-life antibiotic exposure affects the functions of CD8+ T cells (Aim 2). Collectively, this work will provide novel, mechanistic insights into how early-life antibiotic exposure is affecting the functions of influenza-specific tissue-resident CD8+ T cells. These Aims expect to show an antibiotic-mediated reduction in CD8+ T cell cytotoxicity, cytokine production, and proliferation, as well as changes in specific gene regulatory networks underlying the functional dysregulation. The candidate driving this proposal is currently an MD/PhD student at Cincinnati Children’s Hospital in the laboratory of Dr. Hitesh Deshmukh, who will use this proposal to set a foundation for an independent career as a physician-scientist. The candidate will use this proposal to support his future in the clinic as a pediatric intensivist, where findings from this proposal will uncover new strategies leading to better outcomes for the most vulnerable neonates.