Genetically modified pigs to model NKT cell immunity to influenza virus infection

项目概要： 肺T细胞对于保护宿主免受甲型流感病毒（IAV）感染至关重要。虽然目前的 对流感免疫的理解集中于识别肽抗原的常规MHC限制性T细胞， 非传统的先天性T细胞亚群，如CD 1d限制性不变的自然杀伤T（NKT）细胞，正在出现， 呼吸道免疫系统的组成部分，在呼吸道免疫系统中发挥保护作用和免疫病理学作用， 肺病。这主要是通过它们在屏障器官如肺中产生大量细胞因子， NKT细胞优先聚集。尽管NKT细胞活动被认为是流感的重要组成部分， 由于缺乏合适的动物模型，关于它们对人类感染的影响知之甚少。的 目前的建议试图解决这个知识差距使用猪，它提供了一个很好的翻译模型，以确定 NKT细胞在塑造人类流感免疫力中的作用。利用我们在猪NKT细胞方面的广泛专业知识， 猪流感攻击模型，我们提出了三个目标：目标1将研究NKT细胞作为重要的 宿主因素对IAV易感性有影响。我们已经建立了NKT细胞缺陷型CD 1d敲除（KO）猪， 发现它们比NKT细胞完整的猪排出的病毒更少。目标2将使用相同的猪库存，以确定如何NKT 细胞形成由灭活和修饰的活病毒疫苗提供的预先存在的免疫力。解决这个问题是 重要的是要告知疫苗学家，因为NKT细胞先前已被发现产生免疫反应， 刺激对病毒感染的持久保护。目的3将使用我们的CD 1d-KO猪来确定NKT细胞是否 调节疫苗相关增强型呼吸道疾病（VAERD），这是一种由使用 灭活IAV疫苗，含有与后续攻毒株相同的血凝素亚型病毒，但 实质性抗原性转变。这诱导非中和IgG抗体，其增强病毒摄取到靶细胞中。这些 这些独立但相互关联的目标与此次资助机会的目标非常一致：开发新的模型， 将准确反映人类的流感免疫力，包括更好地模拟疫苗反应的预先存在的免疫力 更好地了解特殊的高危人群。我们的发现对于减少 流感传播和提高疫苗的安全性和有效性，因为有几种治疗方案可以调节流感病毒的传播， NKT细胞的频率和功能。

PROJECT SUMMARY: Pulmonary T cells are critical for host protection from influenza A virus (IAV) infections. While current understanding of influenza immunity is focused on conventional MHC-restricted T cells that recognize peptide antigens, unconventional innate-like T cell subsets, such as CD1d-restricted invariant natural killer T (NKT) cells, are emerging as integral components of the respiratory immune system where they play both a protective and immunopathological role in lung disease. This is principally through their production of large amounts of cytokines in barrier organs like the lung where NKT cells preferentially accumulate. Although NKT cell activities are thought to make up a substantial portion of influenza immunity, relatively little is known about their impact on human infections due to a lack of suitable animal models. The current proposal seeks to address this knowledge gap using swine, which offer an excellent translational model to determine the role NKT cells play in shaping human influenza immunity. Using our extensive expertise in porcine NKT cells and the swine influenza challenge model, we propose three aims: Aim 1 will examine the significance of NKT cells as an important host factor contributing to IAV susceptibility. We have already created NKT cell-deficient CD1d knockout (KO) pigs and discovered that they shed less virus than NKT cell-intact pigs. Aim 2 will use the same pig stock to determine how NKT cells shape the pre-existing immunity afforded by inactivated and modified live virus vaccines. Addressing this question is important to inform vaccinologists since NKT cells have previously been found to generate immune responses that could stimulate durable protection against viral infections. Aim 3 will use our CD1d-KO pigs to determine whether NKT cells modulate vaccine associated enhanced respiratory disease (VAERD), which is a dangerous condition caused by the use of inactivated IAV vaccines containing a virus of the same hemagglutinin subtype as the subsequent challenge strain, but with substantial antigenic shift. This induces non-neutralizing IgG Abs that enhances virus uptake into the target cells. These independent but interconnected aims strongly align with the goals of this funding opportunity: to develop novel models that will accurately reflect influenza immunity in humans, including to better mimic pre-existing immunity for vaccine responses and to better understand special high-risk human populations. Our findings should be of considerable value for reducing influenza transmission and improving vaccine safety and efficiency as there are several therapeutic options to modulate the frequency and function of NKT cells.