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

项目总结/摘要 在病毒性肺炎的任何年龄组中，新生儿的感染相关死亡率最高 造成每年约100万人死亡中的大部分。大多数新生儿在 新生儿重症监护室（NICU）接受经验性抗生素治疗。这种抗生素暴露 免疫的发展失调，包括流感特异性CD 8 + T细胞，尽管 早期抗生素暴露究竟如何影响组织驻留的形成和功能， CD 8 + T细胞是不清楚的。由于其作为病毒感染适应性应答者的典型作用，CD 8 + T细胞是直接和长期宿主防御中的关键效应免疫细胞， 严重的病毒性肺炎更好地定义生命早期抗生素暴露 破坏组织驻留的CD 8 + T细胞的形成和功能，以减少实质性的 新生儿肺炎相关死亡率。本提案中的初步流式细胞术数据显示， 早期抗生素暴露减少了流感特异性CD 8 + T细胞的形成， 导致更高的病毒负荷和发病率。初步的单细胞RNA（scRNA-）和单细胞RNA 转座酶可及染色质测序（scATACseq）数据的测定显示了类似的结果。 肺CD 8 + T细胞减少，由基因调控网络中的特定改变控制。 这一数据推动了这一提议的总体假设，即生命早期的抗生素暴露 导致组织驻留CD 8 + T细胞的形成和功能减少， 包括原发性和异型甲型流感感染。本提案将通过以下方式检验这一假设： 确定生命早期抗生素暴露对CD 8 + T细胞形成和功能的影响 用甲型流感病毒（Aim 1）攻击后肺中的细胞，并确定 控制这种早期抗生素暴露如何影响CD 8 + T细胞功能的机制 (Aim 2）。总的来说，这项工作将提供新的，机械的见解如何早期生命抗生素 暴露影响流感特异性组织驻留CD 8 + T细胞的功能。这些目标 预期显示出CD 8 + T细胞细胞毒性，细胞因子产生， 和增殖，以及特定基因调控网络的变化， 功能失调推动这一提案的候选人目前是一名MD/PhD学生， 辛辛那提儿童医院的Hitesh Deshmukh博士的实验室，他将使用这一建议 为作为一名独立的物理学家和科学家奠定基础。候选人会用这个 建议，以支持他的未来在诊所作为一个儿科重症监护医生，其中的结果，从这个 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.