Inducing NK cells to remember and fight cancer

 描述(申请人提供)：NK细胞识别病毒感染和恶性细胞，并通过直接靶细胞杀伤和产生炎性细胞因子来反应。在人类中，我们已经证明过继转移NK细胞可以诱导难治性急性髓系白血病(AML)患者的缓解，而造血细胞移植(HCT)可以治愈AML。尽管在这两种情况下都能看到临床上的成功，但移植后NK细胞的存活率和功能往往不理想，导致癌症复发。我们的研究表明，与未重新激活人巨细胞病毒(HCMV)或HCMV血清阴性的AML患者相比，HCT后重新激活潜伏的人巨细胞病毒(HCMV)的AML患者重建的终末分化的NK细胞具有更强的效应功能。最近的几项临床研究也表明，HCT后早期重新激活HCMV与降低复发风险有关。巨细胞病毒增强NK细胞分化和功能的分子基础尚不清楚。我们有大量的初步数据显示，在健康的HCMV血清阳性的供者和经历了HCMV重新激活的移植受者中，缺乏近端信号分子Fc？R1g、SYK和EAT-2的NK细胞数量增加。这些新的NK细胞具有全基因组的表观遗传学特征，与效应CD8T细胞显着相似，具有显著的microRNA特征。它们在至少一年的时间里以稳定的频率存在，并且它们表现出增强的功能，以响应通过CD16的信号。这些细胞似乎相当于人类对小鼠巨细胞病毒(MCMV)特异反应的适应性或“记忆”NK细胞。由于它们的功能和存活特性，人们对将它们用于免疫治疗有相当大的兴趣。在这 我们的目标是使用一种无偏见的、尖端的深度测序方法，研究在我们独特的移植患者队列中的NK细胞中，当巨细胞病毒重新激活时，microRNAs在适应性人类NK细胞分化中的作用。我们将检验这一假设，即适应性NK细胞的扩张需要通过激活受体来传递信号，并确定五聚体HCMV蛋白复合体和针对这些复合体的高亲和力抗体在触发扩张中的作用。我们有初步的数据表明，在HCMV诱导的适应性NK细胞中选择性地诱导了Notch/TCF-1和Wnt信号通路，我们将利用我们明确的移植队列和体外分析来深入研究这两个通路在适应性NK细胞发育和分化中的作用。我们还将结合我们最近开发的过继人类NK细胞转移异种模型和新的小鼠系统性HCMV感染模型，研究HCMV诱导的适应性NK细胞在体内的存活、归巢和功能。我们由领先的基础和临床NK细胞生物学家、巨细胞病毒专家和小鼠免疫学家组成的团队能够很好地执行这些研究，并将其转化为治疗方法，使NK细胞具有强大的功能并延长生存期，用于癌症的临床治疗。

 DESCRIPTION (provided by applicant): NK cells recognize virally infected and malignant cells and respond by direct target cell killing and the production of inflammatory cytokines. In humans, we have shown that adoptive transfer of NK cells can induce remission in patients with refractory acute myelogenous leukemia (AML) and that hematopoietic cell transplantation (HCT) can cure AML. Although clinical success is seen in both settings, NK cell survival and function are often suboptimal after transplant, resulting in cancer relapse. We have shown that AML patients who reactivate latent human cytomegalovirus (HCMV) post-HCT reconstitute more terminally differentiated NK cells with potent effector function relative to those who do not reactivate HCMV or are HCMV seronegative. Several clinical studies have also recently shown that HCMV reactivation early after HCT is associated with reduced relapse risk. The molecular basis for enhanced NK cell differentiation and function in response to HCMV is unknown. We have extensive preliminary data showing that, in healthy HCMV seropositive donors and in transplant recipients that experience HCMV reactivation, populations of NK cells lacking the proximal signaling molecules Fc¿R1g, SYK and EAT-2 expand. These novel NK cells have a genome wide epigenetic profile markedly similar to that of effector CD8+ T cells with a striking microRNA signature. They are present at stable frequencies over the course of at least one year, and they exhibit enhanced function in response to signaling through CD16. These cells appear to represent a human equivalent to adaptive or "memory" NK cells in mice that respond specifically to mouse cytomegalovirus (MCMV). Because of their functional and survival properties, there is considerable interest in being able to utilize them for immunotherapy. In this proposal, we aim to study the role of microRNAs in the differentiation of adaptive human NK cells upon HCMV reactivation in NK cells from our unique cohort of transplant patients using an unbiased, cutting-edge deep-sequencing approach. We will test the hypothesis that signaling through activating receptors is required for the expansion of adaptive NK cells and determine the role of pentameric HCMV protein complexes and high-affinity antibodies to these complexes in triggering expansion. We have preliminary data suggesting that the Notch/TCF-1 and Wnt signaling pathways are selectively induced in HCMV-induced adaptive NK cells, and we will study the role of both pathways in the development and differentiation of adaptive NK cells in depth using our well defined transplant cohorts and in vitro assays. We will also combine our recently developed xenogeneic model for adoptive human NK cell transfer with a new model for systemic HCMV infection in mice to study HCMV-induced adaptive NK cell survival, homing and function in vivo. Our team of leading basic and clinical NK cell biologists, HCMV experts and mouse immunologists are well positioned to perform these studies and translate them to therapies that can prime NK cells for potent function and prolonged survival for clinical use in the treatment of cancer.