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

项目总结： 肺T细胞对于宿主免受甲型流感病毒(IAV)感染的保护至关重要。当当前 对流感免疫的了解主要集中在识别多肽抗原的传统MHC限制性T细胞上， 非传统的先天T细胞亚群，如CD1d限制的不变自然杀伤T(NKT)细胞，正在成为 呼吸道免疫系统的组成部分，在其中起到保护和免疫病理作用 肺部疾病。这主要是通过它们在肺等屏障器官中产生大量细胞因子来实现的 NKT细胞优先聚集。尽管NKT细胞活动被认为构成了流感的很大一部分 在免疫方面，由于缺乏合适的动物模型，人们对它们对人类感染的影响知之甚少。这个 目前的提案试图使用猪来解决这一知识鸿沟，它提供了一个很好的转换模型来确定 NKT细胞在塑造人类流感免疫中所起的作用。利用我们在猪NKT细胞和 猪流感模型的挑战，我们提出了三个目标：目标1将考察NKT细胞的重要意义 导致IAV易感性的宿主因素。我们已经创造了NKT细胞缺陷的CD1d基因敲除(KO)猪和 发现它们比NKT细胞完整的猪排出的病毒更少。Aim 2将使用相同的生猪数量来确定NKT如何 细胞塑造灭活和改良活病毒疫苗提供的先前存在的免疫力。解决这个问题的方法是 通知疫苗专家很重要，因为之前已经发现NKT细胞产生免疫反应，可以 刺激对病毒感染的持久保护。AIM 3将使用我们的CD1d-KO猪来确定NKT细胞 调制疫苗相关的增强型呼吸道疾病(VAERD)，这是一种危险的情况，由使用 含有与后续挑战毒株相同血凝素亚型病毒的灭活IAV疫苗，但 显著的抗原性转变。这会诱导非中和抗体，增强病毒对靶细胞的摄取。这些 独立但相互关联的目标与这一融资机会的目标非常一致：开发新的模式， 将准确地反映人类的流感免疫，包括更好地模拟疫苗反应的先前存在的免疫 并更好地了解特殊的高危人群。我们的发现应该对减少 流感传播和提高疫苗的安全性和效率，因为有几种治疗方案可以调节 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.