Vaccine-Induced Mucosal T-Cell Immunity to Respiratory Viruses in Dirty Mice

摘要：几十年来，呼吸道感染一直是全球死亡的三大主要原因之一。他们的 新的高传染性呼吸道病原体的出现加强了重要性，正如目前所看到的那样， SARS-CoV-2和过去的流感大流行。目前的流感和SARS-CoV-2疫苗都集中在诱导 需要针对高度可变的病毒表面蛋白的抗体，并且需要频繁的疫苗重新配制以匹配抗原性 不断进化的病毒株或变异体逃避疫苗引发的抗体。因此，激发肺组织- 常驻记忆T细胞（TRM）识别在病毒变体中保守的表位，这对于引起广泛的免疫应答至关重要。 抗病毒免疫我们已经开发了基于组合澄清剂的亚单位粘膜疫苗制剂， 特别强大和功能多样的肺/气道CD8和CD4 TRM，并提供有效和广泛的 在无特定病原体（SPF）小鼠中对甲型流感病毒（IAV）和SARS-CoV-2的保护。然而，一个中央 问题是SPF小鼠的疫苗有效性研究是否可转化为人类，人类暴露于各种 微生物种类近年来，脏小鼠（SPF小鼠与宠物商店小鼠共饲养）已被用于模拟人类 免疫反应。值得注意的是，脏小鼠的TRM数量大大增加，但其潜在机制是 未知我们有令人兴奋的初步数据，脏小鼠的肺和脾有显着增加的数量， 具有转录属性的粒酶BHI/CD44HI CD8 T细胞（T-betLO/EOMESLO/TCF-1LO），使人联想到前体 TRM，这是准备为TRM细胞的命运。首要目标是利用我们组合的高分辨率 基于清洁剂的疫苗方法和脏小鼠模型，以阐明不同微生物暴露对 前TRM的发展及其随后分化为保护呼吸道病毒的TRM。具体 目的1验证不同微生物暴露对肺发育和保护功能的影响 针对IAV和SARS-CoV-2的TRM。在这里，我们将比较肺TRM的发展和转录编程 两种佐剂疫苗组合制剂诱导的SPF和SPF中对IAV和SARS-CoV-2的保护性免疫， 脏老鼠具体目标2将检验以下假设：不同的微生物暴露促进 这导致了免疫接种的脏小鼠肺中TRM的分化增强。在这里，在肮脏的 和SPF小鼠，我们将深刻剖析不同的微生物暴露是否会增强幼稚CD8的预处理。 或CD4 T细胞和/或疫苗接种过程中抗原活化的效应T细胞对TRM细胞命运的影响。 影响：拟议的研究将利用微生物暴露来提高小鼠模型的严谨性，以预测人类的免疫功能。 对疫苗的免疫反应，并提供在条件下肺中TRM发展的机制见解 各种微生物的暴露。因此，这种探索性的“高回报”R21应用融合了意义和创新 为进一步的机理研究奠定概念框架，为发展 生物学相关和可翻译的临床前动物模型，以了解我们如何利用微生物群来增强疫苗- 诱导对IAV和SARS-CoV-2的T细胞免疫，这是具有公共卫生重要性的人类呼吸道病毒。

Abstract: Respiratory infections have been among the top three leading causes of global deaths for decades. Their importance is reinforced by the emergence of novel highly transmissible respiratory pathogens, as witnessed in the current SARS-CoV-2 and past influenza pandemics. Current influenza and SARS-CoV-2 vaccines are focused on eliciting antibodies to highly mutable viral surface proteins, and frequent vaccine reformulations are needed to match the antigenicity of constantly evolving viral strains or variants that evade vaccine-elicited antibodies. Therefore, elicitation of lung tissue- resident memory T cells (TRMs), which recognize epitopes that are conserved across viral variants is critical to elicit broad anti-viral immunity. We have developed combination adjuvant-based subunit mucosal vaccine formulations that elicit exceptionally strong and functionally diverse lung/airway CD8 and CD4 TRMs and provide effective and broad protection against influenza A virus (IAV) and SARS-CoV-2 in specific-pathogen-free (SPF) mice. However, a central question is whether vaccine efficacy studies in SPF mice are translatable to humans, who are exposed to diverse microbial species. In recent years, Dirty mice (SPF mice cohoused with pet store mice), have been used to model human immune responses. Significantly, TRM numbers are greatly increased in Dirty mice, but the underlying mechanisms are unknown. We have exciting preliminary data that the lungs and spleen of Dirty mice have markedly elevated number of Granzyme BHI/CD44HI CD8 T cells with transcriptional attributes (T-betLO/EOMESLO/TCF-1LO) reminiscent of precursor TRMs, which are poised for a TRM cell fate. The overarching goal is to exploit the high resolution of our combination adjuvant-based vaccine approach and the Dirty mouse model to elucidate the effects of diverse microbial exposure on the development of pre-TRMs and their subsequent differentiation into TRMs that protect against respiratory viruses. Specific Aim 1 will test the hypothesis that diverse microbial exposure influences the development and protective functions of lung TRMs against IAV and SARS-CoV-2. Here, we will compare the development and transcriptional programming of lung TRMs induced by two combination adjuvant vaccine formulations and protective immunity to IAV and SARS-CoV-2 in SPF and Dirty mice. Specific Aim 2 will test the hypothesis that diverse microbial exposure promotes the conditioning of circulating/lymphoid pre-TRMs, leading to enhanced differentiation of TRMs in lungs of vaccinated Dirty mice. Here, in Dirty and SPF mice, we will incisively dissect whether diverse microbial exposure enhances the pre-conditioning of naïve CD8 or CD4 T cells prior to vaccination and/or antigen-activated effector T cells during vaccination, to a TRM cell fate. Impact:. Proposed studies will leverage microbial exposure to improve the rigor of mouse models to predict human immune response to vaccines, and provide mechanistic insights into the development of TRMs in the lung under conditions of diverse microbial exposure. Hence, this exploratory ‘high pay off’ R21 application blends significance and innovation to lay the conceptual framework for further mechanistic investigations that will pave the way for the development of a biologically relevant and translatable pre-clinical animal model to learn how we can leverage microbiota to enhance vaccine- induced T-cell immunity to IAV and SARS-CoV-2, which are human respiratory viruses of public health importance.