Regulation of MCMV Persistence by Natural Killer Cells

 描述（由申请方提供）：β-疱疹病毒鼠巨细胞病毒（MCMV）是人CMV的同源物，是一种充分表征的病毒感染动物模型，可导致免疫活性动物的非复制性慢性感染。MCMV在几天内从脾脏和肝脏中清除，但在唾液腺中持续数周。NK细胞对于在T细胞可以产生靶向效应子应答之前在脾脏中早期遏制MCMV至关重要。我们的初步数据表明，脾脏窝藏主要是经典的NK细胞，而肝脏和唾液腺窝藏两个不同的NK细胞亚群。于过往 我们的工作表明，唾液腺NK细胞是低反应性的，可能解释了MCMV在该器官中的持久性。我们的新的初步数据表明，唾液腺NK细胞恢复正常的效应功能，对MCMV过继转移到不同的组织环境。因此，我们的数据表明，唾液腺微环境调节NK细胞和/或NK样细胞通过校准其活性阈值。在这里，我们提出了旨在揭示导致MCMV持续存在的潜在机制的实验。我们将在受体水平和随后的下游信号传导过程中靶向NK细胞。通过使用遗传和生物化学方法，我们将尝试调节它们的效应子功能。在特定目标1中，使用具有SHP-1和SHP-2靶向突变的小鼠，我们将确定NK细胞对MCMV应答的性质。在具体目标2中，我们测试了钙粘蛋白/KLRG 1相互作用的影响。在具体目标3中，我们将确定MCMV感染期间唾液腺E4 BP 4依赖性和E4 BP 4非依赖性NK细胞的各自贡献。从拟议的工作中产生的发现可能会导致逆转CMV持续性的药物的开发。

 DESCRIPTION (provided by applicant): The β-herpes virus murine cytomegalovirus (MCMV), a homologue of human CMV, is a well-characterized animal model of viral infection that results in a non-replicative, chronic infection of an immune-competent animal. MCMV is cleared within days from the spleen and the liver, but persists in the salivary glands for several weeks. NK cells are crucial for the early containment of MCMV in the spleen before T cells can mount a targeted effector response. Our preliminary data show that the spleen harbors mostly classical NK cells, while the liver and the salivary glands harbor two distinct subsets of NK cells. In prior work, we have shown that the salivary gland NK cells are hyporesponsive, possibly explaining the MCMV persistence in this organ. Our new preliminary data show that salivary gland NK cells regain normal effector functions against MCMV when adoptively transferred into different tissue environments. Therefore, our data suggest that the salivary gland microenvironment regulates NK cells and/or NK-like cells by calibrating their threshold of activity. Here we propose experiments designed to reveal the underlying mechanisms leading to MCMV persistence. We will target NK cells at the receptor level and during subsequent downstream signaling. By using both a genetic and biochemical approach, we will attempt to modulate their effector functions. In Specific Aim 1, using mice with targeted mutations for SHP-1 and SHP-2, we will determine the nature of the NK cell response to MCMV. In Specific Aim 2, we test the impact of cadherin/KLRG1 interaction. In Specific Aim 3, we will determine the respective contribution of salivary gland E4BP4- dependent and E4BP4-independent NK cells during MCMV infection. The findings generated from the proposed work could potentially lead to the development of drugs that reverse CMV persistence.