Transcriptional mechanisms of natural killer cell responses during mouse cytomegalovirus infection

项目摘要 自然杀伤（NK）细胞是免疫系统的淋巴细胞，可以检测和杀死病毒感染的细胞。 流行病学研究表明，免疫抑制（如癌症，器官移植，艾滋病）患者 和新生儿显示出与人类巨细胞病毒相关的健康并发症的风险增加 （HCMV）感染，可能危及生命。先前的研究表明，小鼠巨细胞病毒（MCMV） 小鼠中的感染可以准确地模拟HCMV感染，并证明NK细胞对HCMV感染的关键性。 MCMV的控制。此外，NK细胞已被证明具有适应性免疫系统的特性 例如小鼠、猕猴和人的回忆反应、抗原特异性和克隆扩增。虽然 我们的工作在阐明自噬和线粒体自噬是如何导致 记忆NK细胞和增殖淋巴细胞的存活，这些细胞的上游调控元件 体内淋巴细胞的基本生物学过程仍然知之甚少。我们的长期目标是 确定诱导自噬、线粒体自噬和记忆NK细胞存活的相关转录信号， 病毒感染后的细胞。在RNA测序实验中，我们已经确定Trp73（p73）是一种 小鼠巨细胞病毒感染后记忆NK细胞中选择性富集的转录因子 感染通过qRT-PCR的进一步实验验证揭示了小鼠中Trp73的两种主要同种型 在MCMV感染期间，TAp73和Δ Np73在NK细胞中显示不同的时间表达模式。 重要的是，p73转录异构体在体内淋巴细胞对病毒感染的应答中的作用是 未知我们令人兴奋的初步发现表明，Δ Np73在效应NK细胞中被瞬时诱导， 克隆扩增和产生记忆NK细胞所需的。相反，TAp73表达持续 在效应和记忆NK细胞中，并对效应NK细胞增殖有抑制作用，但对存活和 记忆NK细胞的产生。在目标1中，我们将确定TAp73是否影响自噬去除。 NK细胞中的线粒体功能障碍，以促进效应NK细胞的存活，因为它们过渡到记忆 细胞使用先进的自噬和代谢分析。在目标2中，我们将确定Δ Np73是否导致 通过抑制p53来保护NK细胞免于凋亡或减轻NK细胞的增殖， 细胞周期抑制在目标3中，我们将进行RNA和ChIP测序实验，以确定基因 p73在效应NK细胞中的靶点。总而言之，本报告中包含的拟议研究 R01的提议将有助于我们对原代细胞如何在体内诱导线粒体自噬的基本理解， 也有助于新的临床策略，以增强免疫的适应性NK细胞应答的使用， 对抗传染病

Project Summary Natural killer (NK) cells are lymphocytes of the immune system that can detect and kill virally infected cells. Epidemiological studies have shown that immunosuppressed (e.g. cancer, organ transplant, AIDS) patients and newborns display an enhanced risk for health complications associated with human cytomegalovirus (HCMV) infection that can be life-threating. Previous work has shown that mouse cytomegalovirus (MCMV) infection in mice can accurately model HCMV infection, and demonstrated that NK cells are critical for the control of MCMV. Furthermore, NK cells have been shown to have properties of the adaptive immune system such as recall responses, antigen-specificity, and clonal expansion in mice, macaques, and humans. Although our work has made significant progress into elucidating how autophagy and mitophagy lead to the generation of memory NK cells and the survival of proliferating lymphocytes, the upstream regulatory elements of these fundamental biological processes remain poorly understood in lymphocytes in vivo. Our long-term goals seek to identify the relevant transcriptional signals that induce autophagy, mitophagy, and survival of memory NK cells following viral infection. In RNA-sequencing experiments, we have identified Trp73 (p73) as a transcription factor selectively enriched in memory NK cells following murine cytomegalovirus (MCMV) infection. Further experimental validation by qRT-PCR revealed that two dominant isoforms of Trp73 in mice (TAp73 and ΔNp73) display distinct temporal expression patterns in NK cells during MCMV infection. Importantly, the roles of p73 transcriptional isoforms in lymphocyte responses to viral infection in vivo are unknown. Our exciting preliminary findings suggest that ΔNp73 is transiently induced in effector NK cells and is required for clonal expansion and generation of memory NK cells. In contrast, TAp73 expression is sustained in effector and memory NK cells and is dispensable for effector NK proliferation, but critical for the survival and generation of memory NK cells. In Aim 1, we will determine whether TAp73 influences autophagic removal of dysfunctional mitochondria in NK cells to promote the survival of effector NK cells as they transition to memory cells using cutting-edge autophagy and metabolism assays. In Aim 2, we will determine whether ΔNp73 leads to the proliferation of effector NK cells through repression of p53 to shield NK cells from apoptosis or relieve cell cycle repression. In Aim 3, we will perform RNA and ChIP-sequencing experiments to determine the gene targets of p73 in effector NK cells using genomic analyses. In summary, the proposed studies included in this R01 proposal will contribute to our basic understanding of how primary cells induce mitophagy in vivo, while also contributing to novel clinical strategies to enhance the use of adaptive NK cell responses for immunization against infectious disease.