Preterm birth, lung innate immunity, and RSV

早产、肺部先天免疫和 RSV

• 批准号: 6965619
• 负责人: Mark R Ackermann
• 金额: $ 22.96万
• 依托单位: IOWA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6965619
• 关键词: RNA interference; alveolar macrophages; cell differentiation; cell proliferation; defensins; dendritic cells; disease /disorder proneness /risk; gene expression; gene expression profiling; genetic susceptibility; genetic transcription; gestational age; immunity; immunogenetics; newborn animals; premature infant animal; protein quantitation /detection; pulmonary surfactants; respiratory epithelium; respiratory infections; respiratory syncytial virus; sheep; tissue /cell culture; toll like receptor

DESCRIPTION (provided by the applicant): Respiratory syncytial virus (RSV) infection is the most common cause of respiratory disease leading to hospitalization in children. Preterm infants are especially susceptible to severe RSV infection. Respiratory epithelium is an initial site of RSV infection and epithelial cells along with alveolar macrophages (AM) and dendritic cells (DC) are vital to innate and adaptive immune responses. However, the extent of innate immune gene expression by epithelia and AM-DC in preterm infants can be variable/limited. The hypothesis is that: Reduced innate immunity by respiratory epithelia and AM-DC preterm enhances susceptibility to RSV infection This hypothesis is based on the facts above and our preliminary data in lambs demonstrating limited expression of surfactant proteins A and D (SP-AD), sheep beta-defensin-1 (SBD-1), and Toll-like receptor 4 (TLR4) preterm. It will be tested in preterm lambs which have close similarities with human disease including susceptibility, lesions, and innate immunity. Specific Aim 1 compares expression of key innate immune genes (SBD-1, SP-AD, TLR4) and protein/peptide production in vivo as well as AM-DC cytokine expression in pre- and full-term lung. It also tests the hypothesis that limited epithelial cell proliferation and/or differentiation pre-term underlie(s) the mechanistic basis for limited SP-AD, SDB-1 expression and tests this by comparing transcriptional activity, protein/peptide production in pre- and full term cultured cells with or without cell proliferation and differentiation. Specific Aim 2 tests the hypothesis that SP-AD, SBD-1 and AM-DC responses to RSV are less at pre- than full-term in the lamb model and in vitro with cultured epithelial cells. A second hypothesis, that increased cell proliferation and/or differentiation of epithelia protects against RSV infection, will be tested in vitro with treatments from Aim 1. The extent to which SP-AD, SBD-1 directly prevent RSV infection will be tested with RNAi assays. Specific Aim 3 tests the hypothesis that yet other innate immune genes expressed with cell proliferation/differentiation prevent RSV infection. This Aim uses gene expression profiling of primary polarized human lung cells and a respiratory epithelia-specific probe set (Unigene) that is the most well-annotated and defined gene target set to date. It also identifies ovine orthologs of human genes and test for impaired/reduced expression preterm. This team combines veterinary and human medical expertise to attain the goal of this project: to discover the reason(s) for inadequate expression of SP-AD, SBD-1 and other innate immune genes as well as AMDC responses at preterm that predispose to RSV infection. The work is significant because it discovers the underlying basis for RSV susceptibility preterm and mechanistic approaches to enhance innate immunity.

描述（由申请人提供）：呼吸道合胞病毒（RSV）感染是导致儿童住院的呼吸道疾病的最常见原因。早产儿特别容易受到严重 RSV 感染。呼吸道上皮是 RSV 感染的初始部位，上皮细胞以及肺泡巨噬细胞 (AM) 和树突状细胞 (DC) 对于先天性和适应性免疫反应至关重要。然而，早产儿中上皮细胞和 AM-DC 的先天免疫基因表达程度可能是可变的/有限的。该假说是： 早产儿呼吸道上皮细胞和 AM-DC 的先天免疫力降低会增加对 RSV 感染的易感性 该假说基于上述事实以及我们在羔羊身上的初步数据，这些数据表明早产儿表面活性蛋白 A 和 D (SP-AD)、绵羊 β-防御素-1 (SBD-1) 和 Toll 样受体 4 (TLR4) 的表达有限。它将在早产羔羊身上进行测试，这些羔羊与人类疾病非常相似，包括易感性、病变和先天免疫。具体目标 1 比较了关键先天免疫基因（SBD-1、SP-AD、TLR4）的表达和体内蛋白质/肽的产生，以及足月前和足月肺中 AM-DC 细胞因子的表达。它还测试了这样的假设：足月前有限的上皮细胞增殖和/或分化是有限的 SP-AD、SDB-1 表达的机制基础，并通过比较有或没有细胞增殖和分化的足月前和足月培养细胞的转录活性、蛋白质/肽产生来测试这一点。具体目标 2 检验了以下假设：在羔羊模型中以及体外培养的上皮细胞中，SP-AD、SBD-1 和 AM-DC 对 RSV 的反应在足月前低于足月。第二个假设，即上皮细胞增殖和/或分化的增加可防止 RSV 感染，将通过目标 1 的治疗在体外进行测试。SP-AD、SBD-1 直接预防 RSV 感染的程度将通过 RNAi 测定进行测试。具体目标 3 测试了以下假设：随着细胞增殖/分化而表达的其他先天免疫基因可预防 RSV 感染。该目标使用原代极化人肺细胞的基因表达谱和呼吸道上皮特异性探针组 (Unigene)，这是迄今为止注释最清楚、定义最清楚的基因靶标组。它还鉴定人类基因的绵羊直系同源物并测试早产表达受损/减少。该团队结合了兽医和人类医学专业知识来实现​​该项目的目标：发现 SP-AD、SBD-1 和其他先天免疫基因表达不足以及早产儿 AMDC 反应导致 RSV 感染的原因。这项工作意义重大，因为它发现了早产儿 RSV 易感性的根本基础以及增强先天免疫的机制方法。