Molecular study of mouse viral resistance mechanisms

描述（由申请人提供）：众所周知，NK细胞具有识别和裂解病毒感染细胞的能力。事实上，缺乏NK细胞免疫的人类和小鼠的宿主防御非常容易受到压倒性和复发性疱疹病毒感染的影响。在C57 BL/6小鼠中，宿主抗鼠巨细胞病毒（MCMV）免疫需要NK细胞表达的Ly 49 H活化受体识别MCMV感染细胞上其病毒编码的m157配体。然而，我们最近发现NZW小鼠中的NK细胞控制实验MCMV感染，而Ly 49 H + NK细胞没有作用。在此，我们扩展了我们在MA/My小鼠中的发现。MA/My毒株值得注意，因为它也显示出非常有效的NK细胞介导的MCMV感染控制，但该毒株中的NK细胞不表达Ly 49 H受体。有趣的是，MA/My中的MCMV抗性与MHC和非MHC基因强烈相关。因此，我们发现NK细胞利用多种抗病毒控制机制，这些机制以遗传多态性为特征。因此，这项研究计划的长期目标是了解宿主基因的遗传变异如何在先天免疫中发挥不同的作用，其在感染后早期快速识别和摧毁病毒病原体的能力以及控制这种宿主防御的分子和细胞机制。本文的具体目的将首先关注通过经典孟德尔遗传学研究对先天性抗MCMV免疫有实质性贡献的宿主基因的鉴定和表征。该方法是基于实验MCMV感染后杂交后代的快速表型表征和随后的每个个体的全基因组基因型鉴定。使用这种高通量遗传学策略，将在定量遗传学策略中确定染色体位置，在间隔特异性同源菌株中确认，随后将在前瞻性分子和生化分析中评估候选基因。为了便于鉴定宿主病毒抗性基因，我们还将在细胞毒性试验中研究NK细胞对病毒感染的识别，并且还将使用病毒株变体选择来从机制上理解宿主的先天防御。虽然NK细胞在感染后和适应性免疫能力之前立即采用多种防御机制来控制病毒病原体，但我们的研究无疑将对CMV和潜在的其他病毒感染中的人类先天防御产生重要影响。

DESCRIPTION (provided by applicant): NK cells are well known for the capacity to recognize and lyse virus infected cells. Indeed, host defenses in humans and mice that lack NK cell immunity are quite vulnerable to overwhelming and recurrent Herpes virus infections. In C57BL/6 mice, host anti-murine cytomegalovirus (MCMV) immunity requires NK cell expressed Ly49H activation receptor recognition of its virus encoded m157 ligand on MCMV infected cells. We recently showed that NK cells in NZW mice however, control experimental MCMV infection without a role for Ly49H+ NK cells. Herein we have extended our finding in MA/My mice. The MA/My strain is noteworthy since it also displays very effective NK cell-mediated control of MCMV infection, but NK cells in this strain do not express Ly49H receptors. Interestingly, MCMV resistance in MA/My is strongly associated with MHC and also non MHC genes. Thus, we have found that NK cells utilize multiple antiviral control mechanisms that are distinguished by genetic polymorphism. The long-term objective of this research proposal therefore is to understand how genetic variation in host genes can contribute differently in innate immunity, its capacity to rapidly recognize and destroy viral pathogens at early times after infection and the molecular and cellular mechanisms controlling such host defenses. The Specific Aims herein will focus initially on the identification and characterization of host genes that contribute substantially to innate anti-MCMV immunity through classical Mendelian genetics studies. The approach is based on rapid phenotypic characterization of hybrid offspring after experimental MCMV infection and subsequent genome-wide genotypic identification of each individual. Using this high-throughput genetics strategy, chromosome locations will be identified in quantitative genetics strategies, confirmed in interval-specific congenic strains, and subsequently candidate genes will be assessed in prospective molecular and biochemical analyses. To facilitate identification of host virus resistance genes, we will also investigate NK cell recognition of virus infection in cellular cytotoxicity assays and virus strain variant selection will also be used to understand innate host defenses mechanistically. While NK cells employ multiple defense mechanisms to control viral pathogens immediately after infection and before adaptive immunity is competent, our studies will no doubt have important implications for human innate defenses in CMV and potentially other virus infections.