Variable natural killer cell responses in the control of Epstein-Barr virus infection

项目摘要 1 EB病毒（EBV）感染约95%的个体，大多数具有无症状、潜伏性 2感染。然而，EBV可以在一些情况下驱动免疫病理学和恶性疾病，导致>1%的 全球3例癌症死亡。免疫系统在确定无症状和无症状之间的平衡方面至关重要。 4病原体感染。自然杀伤（NK）细胞起着重要作用：NK细胞识别并杀死EBV感染的细胞。 5细胞和NK细胞缺乏导致严重的EBV疾病。NK细胞功能受生殖系编码的 6 NK细胞受体，其接合在感染细胞上表达的配体。在这些受体中， 7免疫球蛋白样受体（KIR），识别人类白细胞抗原（HLA）作为配体。两个KIR 8和HLA是极其多态的，并且它们的连接是同种异型特异性的，使得个体具有独特的 9种HLA和KIR同种异型的库，其决定了它们对感染的NK细胞应答。此外，具体 10肽可以改变KIR连接，包括已知改变KIR-HLA结合的三种EBV肽。 11有趣的是，KIR、HLA和EBV的遗传变异与EBV疾病单独相关， 12在预期改变KIR和HLA之间的肽特异性结合的位置观察到EBV多态性。 虽然这些遗传关联表明HLA、KIR和EBV基因型决定了功能不同的NK细胞， EBV发病过程中的14种反应，KIR/HLA遗传变异在控制EBV感染前的影响 15至疾病发作，以及宿主和病毒遗传变异之间的相互作用，仍然没有特征。此外，本发明还 16 KIR介导的针对EBV的抗病毒免疫背后的免疫学机制在功能上没有定义。 17.拟议的研究将检验KIR和HLA肽之间的同种异型特异性连接的假设。 18种复合物决定了个体和EBV毒株之间的NK细胞应答，导致基因型依赖性 19免疫控制EBV感染。目的1将鉴定KIR、HLA和EBV基因型，这些基因型单独或 使用来自20个不同人群的样本，将20个样本与循环EBV负荷联合相关。这些遗传 21个关联将与KIR-HLA功能数据（如连接亲合力和信号强度）整合， 22辨别NK细胞教育和抗原识别在控制EBV感染中的作用。目标2将补充 23通过功能性测试KIR和HLA同种异型对的能力， 24 NK细胞对EBV感染的细胞的细胞溶解功能。作为NK细胞识别基础的KIR和HLA同种异型 将鉴定25%的EBV感染细胞，以及能够或破坏NK细胞的EBV肽和多态性。 通过KIR和HLA杀伤26细胞。总之，这些目标将决定HLA和KIR多态性在 NK细胞介导的EBV感染控制，提供了驱动EBV感染的免疫机制的清晰度。 28建立了EBV疾病与HLA、KIR和EBV基因型之间的关联。拟议的研究和 29种方法也将促进我在人类免疫学和遗传学研究方面的培训， 30必要的背景过渡到终身职位的作用研究遗传学基础的DNA病毒免疫。

Project summary 1 Epstein-Barr virus (EBV) infects approximately 95% of individuals, with most having an asymptomatic, latent 2 infection. However, EBV can drive immunopathological and malignant diseases in some, resulting in >1% of 3 global cancer deaths. The immune system is critical in determining the balance between asymptomatic and 4 pathogenic infection. Natural Killer (NK) cells play an important role: NK cells recognize and kill EBV-infected 5 cells, and NK cell deficiencies lead to severe EBV disease. NK cell functions are modulated by germline-encoded 6 NK cell receptors, which engage ligands expressed on infected cells. Among these receptors are the Killer cell 7 immunoglobulin-like receptors (KIR), which recognize Human Leukocyte Antigen (HLA) as ligands. Both KIR 8 and HLA are extremely polymorphic, and their ligation is allotype-specific, such that individuals have a unique 9 repertoire of HLA and KIR allotypes that determines their NK cell response to infection. Further, the specific 10 peptide presented by HLA can alter KIR ligation, including three EBV peptides known to alter KIR-HLA binding. 11 Intriguingly, genetic variants in KIR, HLA, and EBV are individually associated with EBV disease, and I have 12 observed EBV polymorphism in positions expected to alter peptide-specific binding between KIR and HLA. 13 While these genetic associations suggest HLA, KIR, and EBV genotypes determine functionally distinct NK cell 14 responses during EBV pathogenesis, the impact of KIR/HLA genetic variation in controlling EBV infection prior 15 to disease onset, and the interactions between host and viral genetic variation, remain uncharacterized. Further, 16 the immunological mechanisms behind KIR-mediated antiviral immunity to EBV are not functionally defined. 17 The proposed research will test the hypothesis that allotype-specific ligation between KIR and HLA-peptide 18 complexes determine NK cell responses across individuals and EBV strains, resulting in genotype-dependent 19 immune control of EBV infection. Aim 1 will identify the KIR, HLA, and EBV genotypes that are individually or 20 jointly associated with circulating EBV load, using samples from 20 diverse populations. These genetic 21 associations will be integrated with KIR-HLA functional data, such as ligation avidity and signaling strength, to 22 discern the role of NK cell education and antigen recognition in controlling EBV infection. Aim 2 will complement 23 the identified genetic associations by functionally testing the ability of pairs of KIR and HLA allotypes to direct 24 NK cell cytolytic functions towards EBV-infected cells. KIR and HLA allotypes that underlie NK cell recognition 25 of EBV-infected cells will be identified, as will the EBV peptides and polymorphisms that enable or disrupt NK 26 cell killing through KIR and HLA. Together, these aims will determine the role of HLA and KIR polymorphism in 27 the NK cell-mediated control of EBV infection, providing clarity on the immunological mechanisms driving 28 established associations between EBV disease and HLA, KIR, and EBV genotypes. The proposed research and 29 methodologies will also facilitate my training in human immunology and genetics research, providing the 30 background necessary to transition into a tenure-track role studying the genetics underlying DNA virus immunity.