Natural killer cell subsets characterisation in blood and peripheral lymph node in natural host during simian immunodeficiency virus infection

The goal of this project is todetermine if natural killer (NK) cells could be able to control HIV replication and reduce or eliminate viral reservoirs leading to HIV cure or a functional cure. Despite thirty years of work and significant progress, HIV infection continues to be an incurable disease. Antiretroviral therapy (ART) has significantly decreased the morbidity and mortality, but lifelong treatment is merely suppressive and does not cure HIV/AIDS. This is because of the existence of a reservoir of viral DNA+ (vDNA+) in cells of the lymphoid tissues with an intact provirus that is thought capable of initiating new rounds of HIV replication (i.e. latency). In addition to this inducible reservoir data suggest ongoing low-level virus replication and persistence in lymphatic tissues of some patients that is related to suboptimal drug levels in these tissues. Strategies are needed that can address both issues. NK cells are innate immune effectors that recognize virally infected targets through a cadre of activating and inhibitory receptors but become dysfunctional in HIV infected people. Strikingly, African green monkeys (AGM) and sooty mangabeys mount a strong control of viral replication in lymph node follicles shortly after the viremia peak that lasts throughout infection. Several mechanisms have been proposed to be implicated in the strong control of viral replication in natural host's lymph nodes, such as NK cell-mediated control. Indeed, we have recently shown that NK cells could migrate into the b cells follicles in a CXCR5 dependent manner and thus participate to the elimination of viral replication. Thus the purpose of this study is too compare at the transcriptomic level different subset of NK cell isolated from blood and peripheral lymph node of chronically infected AGM to identify a transcriptomic signature which could be linked to an efficient control of SIV replication. This results could then provide a new aproche which could be exploited to generate functional NK cells against HIV in infected patients. Overall design: Transcriptome profiling of different NK cells subsets according to CD16 and NKG2a/c expression in blood and peripheral lymph node in SIV infection

本研究的核心目标为探究自然杀伤细胞（natural killer, NK）是否能够抑制HIV复制，并减少或清除病毒储存库，进而实现HIV治愈或功能性治愈。尽管历经三十年的研究并取得了显著进展，HIV感染仍是一种无法根治的疾病。抗逆转录病毒治疗（antiretroviral therapy, ART）可显著降低HIV/AIDS的发病率与死亡率，但终身治疗仅能实现病毒抑制，无法彻底治愈HIV感染。究其原因，淋巴组织细胞中存在携带完整前病毒的病毒DNA阳性（viral DNA+, vDNA+）储存库，这类前病毒被认为可启动新一轮HIV复制（即病毒潜伏）。除了这种可诱导的病毒储存库外，相关数据显示，部分患者的淋巴组织中仍存在持续的低水平病毒复制与存留，这与该组织中药物浓度未达最优水平相关。因此，亟需能够同时解决上述两大问题的治疗策略。

NK细胞属于固有免疫效应细胞，可通过一系列激活型与抑制型受体识别病毒感染的靶标，但在HIV感染者体内其功能会发生失调。值得注意的是，非洲绿猴（African green monkeys, AGM）和乌白眉猴在病毒血症峰值出现后不久，即可在淋巴结滤泡中实现对病毒复制的强力抑制，且该抑制作用贯穿整个感染过程。目前已有多种机制被提出与自然宿主淋巴结内的强效病毒复制控制有关，其中包括NK细胞介导的免疫调控。事实上，我们近期的研究已证实，NK细胞可通过CXCR5依赖的方式迁移至B细胞滤泡，从而参与清除病毒复制。

因此，本研究的目的为在转录组层面分析从慢性感染猴免疫缺陷病毒（simian immunodeficiency virus, SIV）的AGM血液及外周淋巴结中分离的不同NK细胞亚群，以筛选出与高效控制SIV复制相关的转录组特征。该研究结果可为开发针对HIV的功能性NK细胞疗法提供新的思路，进而应用于HIV感染者的治疗。

实验整体设计：针对SIV感染状态下，血液及外周淋巴结中依据CD16与NKG2a/c表达特征分型的不同NK细胞亚群开展转录组谱分析。