Molecular study of mouse viral resistance mechanisms.

我们实验室的长期目标是了解先天免疫系统如何在分子水平上识别和响应病原体入侵，特别是因为这种防御可能由基因组元件控制。特别是，本研究将重点关注NK细胞介导的对小鼠巨细胞病毒（MCMV）的病毒免疫，因为它是由NKO相关的Cmy1位点控制的。值得注意的是，NK细胞通过释放细胞因子（如ifn - γ）和直接细胞介导的细胞毒性机制，是宿主对一系列病原体（包括病毒、细菌和原生动物寄生虫）的先天免疫防御的重要贡献者。此外，NK细胞在小鼠巨细胞病毒（MCMV）感染期间直接限制病毒在小鼠体内的复制，这种能力与MCMV攻击期间宿主的存活直接相关，并且NK细胞介导的免疫直接受到Cmv1位点的调节。Cmv1最近在远端NKC中被定位，但Cmv1候选序列未被报道。在初步数据中，我们报告了另一个NKC编码的NK受体（Ly- 49H）可能参与MCMV抗性，但该NKC基因在物理和遗传上与CMv1位点分离。因此，我们将通过评估新型NKC内重组小鼠和Cmv1阴性/阴性小鼠的MCMV抗性来确定是否需要多个NKC位点的MCMV抗性（Specific Aim 1）。从C57BL/6小鼠和MCMV易感小鼠中选择新的Cmv1编码序列。这些序列将进行结构和生化比较，以确定最佳的Cmv1候选序列。Cmv1候选序列的确认将使用转基因方法进行（Specific Aim 2）。最后，利用转基因方法获得Ly49h与MCMV耐药免疫相关的遗传数据。此外，该基因将在C57BL/6和几种MCMV易感小鼠株中进行彻底的表征（Specific Aim 3）。因此，这些研究应该澄清我们对NK细胞识别病毒感染和cmv1调节的免疫的理解，因为这些目前还没有被理解的机制。

The long-term objective of our laboratory is to understand how the innate immune system recognizes and responds to pathogen invasion at the molecular level, especially since such defenses may be controlled by genomic elements. In particular, this study will focus on NK cell- mediated viral immunity to murine cytomegalovirus (MCMV) as it is controlled by the NKO linked Cmy1 locus. Notably NK cells are important contributors of host innate immune defenses to a range of pathogens including, viruses, bacteria, and protozoan parasites, through cytokines released (e.g. IFN-gamma) and direct cell-mediated cytotoxicity mechanisms. Moreover, NK cells directly limit viral replication in mice during murine cytomegalovirus (MCMV) infection, this capacity directly correlates with host survival during MCMV challenge, and NK cell-mediated immunity is directly regulated by the Cmv1 locus. Cmv1 was recently mapped within the distal NKC, however Cmv1 candidate sequences were not reported. In preliminary data, we report that an additional NKC encoded NK receptor (Ly- 49H) may be involved in MCMV resistance, but this NKC gene is physically and genetically separate from the CMv1 locus. Hence, we will determine whether more than one NKC locus is required MCMV resistance by assessing MCMV resistance in novel intra-NKC recombinant mice and Cmv1 minus/minus mice (Specific Aim 1). Novel Cmv1 coding sequences will be selected form C57BL/6 mice and from MCMV susceptible strains of mice. These sequences will be compared structurally and biochemically to identify a best Cmv1 candidate sequence. Confirmation of Cmv1 candidate sequences will be performed using a transgenic approach (Specific Aim 2). Finally, should genetic data be obtained implicating Ly49h in MCMV resistance immunity using a transgenic approach. Furthermore, this gene will be thoroughly characterized in C57BL/6 and several MCMV susceptible mouse strains (Specific Aim 3). Thus, these studies should clarify our understanding of NK cell recognition of viral infection and Cmv1-regulated immunity, as these are not currently understood mechanistically.