MODIFYING THE LUNG TO INDUCE STERILE VACCINE-INDUCED PROTECTION AGAINST MTB INFECTION

项目摘要 结核分枝杆菌(Mtb)和人类免疫缺陷病毒(HIV)共同代表着 世界上最大的杀手。据估计，每个新确诊的结核病病例有900万例。 每年有140万人死亡。因此，我们开发小说是至关重要的。 控制结核分支杆菌感染的策略。目前唯一获得许可的结核病疫苗--牛分枝杆菌卡介苗 卡介苗(Guerin)对儿童结核病有效，但对肺结核疗效有限 青春期过后。因此，新型结核病疫苗和治疗方法的开发将提供更好的 对结核杆菌暴露的保护是迫切需要的。正在开发的现代候选结核病疫苗 都专注于诱导强烈的T细胞反应，主要是产生细胞因子的CD4T细胞 干扰素-γ，Th1细胞。最近，粘膜白介素17A(IL-17)在 疫苗诱导的对结核病的保护作用也已显示出来。因此，肺内滞留的IL-1的诱导 通过粘膜结核疫苗产生17个CD4T细胞群(Th17细胞)的研究也在进行中。 然而，大多数结核病疫苗并不提供灭菌免疫力，而是导致仅减少~0.5%至 1.5在动物激发模型中记录肺结核分枝杆菌负荷。我们在这里展示的新数据表明， 灭菌疫苗诱导的结核疫苗免疫并不是由于疫苗诱导的CD4功能不佳 T细胞，但由于延迟激活和在肺内积累Recall CD4T细胞反应 结核分枝杆菌感染。使用新的策略，我们证明了这一瓶颈可以通过交付激活的 结核分枝杆菌抗原(Ag)冲击树突状细胞(DC)进入接种结核分枝杆菌感染小鼠的肺部。直流传输 大大加快了CD4T细胞在肺部积累的时间，并导致了更好的疫苗- 结核分枝杆菌感染疫苗小鼠的免疫诱导作用。使用RNAseq分析，我们进一步生成了 接受DC转移的免疫小鼠中与优势疫苗相关的基因签名 结核分枝杆菌感染诱导免疫。这一基因特征反映了相关途径的上调 快速有效地激活肺树突状细胞和T细胞通路。具体来说，我们发现了基因 与DC转移受体中上调的CD103 DC和CD40通路的激活相关 接种结核分枝杆菌感染的小鼠，表现出更好的结核分枝杆菌控制。在此探索性提案中，使用鼠标 疫苗接种和结核分枝杆菌感染的模式，我们将调查靶向宿主肺CD103树突状细胞 而带有新型宿主导向疗法(HDTS)的CD40通路可以诱导灭菌疫苗- 结核分枝杆菌感染后诱导免疫。这些研究将从功能上确定 快速激活疫苗诱导的T细胞对结核病的召回反应。重要的是，这些研究将 还提供新的HDTS以增强疫苗反应，以控制受感染宿主的结核分枝杆菌负担，或 延迟潜伏感染患者的结核病重新激活。

PROJECT ABSTRACT Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus (HIV) together represent the world's biggest killers. There are an estimated nine million new cases of tuberculosis (TB) diagnosed each year, resulting in 1.4 million deaths annually. It is therefore of paramount importance that we develop novel strategies for controlling Mtb infection. The only currently-licensed vaccine for TB, M.bovis Bacille Calmette Guerin (BCG), is effective against childhood forms of TB, but has limited efficacy against pulmonary TB after adolescence. Thus, development of novel vaccines and therapeutics for TB that will provide improved protection upon Mtb exposure are urgently required. Modern candidate TB vaccines under development have focussed on induction of strong T cell responses, primarily CD4+ T cells producing the cytokine interferon gamma (IFN-γ, Th1 cells). More recently, a key role for mucosal interleukin 17A (IL-17) in vaccine-induced protection against TB disease has also been shown. Thus, induction of lung-resident IL- 17-producing CD4+ T cell populations (Th17 cells) by mucosal TB vaccines is also being explored. However, most TB vaccines do not confer sterilizing immunity, instead, inducing a reduction of only ~0.5 to 1.5 logs in lung Mtb burden in animal challenge models. Our new data presented here, show that the lack of sterilizing vaccine-induced immunity to TB vaccines is not due to poor function of vaccine-induced CD4+ T cells, but due to delayed activation and accumulation of recall CD4+ T cell responses in the lung following Mtb infection. Using novel strategies, we show that this bottleneck can be overcome by delivery of activated Mtb antigen (Ag)-pulsed dendritic cells (DCs) into the lungs of vaccinated Mtb-infected mice. DC transfer substantially accelerates the timing of CD4+ T cell accumulation in the lungs, and leads to superior vaccine- induced immunity in Mtb-infected vaccinated mice. Using RNASeq analysis, we have further generated a gene signature in vaccinated mice receiving DC transfer, that is associated with the superior vaccine immunity induced upon Mtb infection. This gene signature reflects upregulation of pathways associated with rapid and effective activation of lung DCs and T cell pathways. Specifically, we found genes associated with activation of CD103+ DC and CD40 pathways upregulated in DC transfer-recipient vaccinated Mtb-infected mice, exhibiting superior Mtb control. In this exploratory proposal, using mouse models of vaccination and Mtb infection, we will investigate whether targeting host lung CD103+ DCs and the CD40 pathway with novel host-directed therapeutics (HDTs) can induce sterilizing vaccine- induced immunity following Mtb infection. These studies will functionally determine the mechanisms that mediate rapid activation of vaccine-induced T cell recall responses to TB. Importantly, these studies will also provide novel HDTs to enhance vaccine responses to either control Mtb burden in infected hosts, or delay TB reactivation in latently-infected individuals.