Inducing NK cells to remember and fight cancer

 描述（由申请方提供）：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进行应答。在人类中，我们已经表明，过继性NK细胞转移可以诱导难治性急性髓细胞白血病（AML）患者的缓解，造血细胞移植（HCT）可以治愈AML。虽然在这两种情况下都取得了临床成功，但NK细胞的存活和功能在移植后往往不理想，导致癌症复发。我们已经表明，相对于那些没有重新激活HCMV或HCMV血清阴性的AML患者，HCT后重新激活潜伏的人巨细胞病毒（HCMV）的AML患者重建了更多具有强效效应功能的终末分化NK细胞。最近的几项临床研究也表明，HCT后早期HCMV再活化与复发风险降低相关。增强NK细胞分化和功能以响应HCMV的分子基础是未知的。我们有大量的初步数据显示，在健康的HCMV血清阳性供体和经历HCMV再活化的移植受体中，缺乏近端信号分子Fc <$R1g、SYK和EAT-2的NK细胞群体扩增。这些新型NK细胞具有与效应CD 8 + T细胞显著相似的基因组范围的表观遗传特征，具有显著的microRNA特征。它们在至少一年的过程中以稳定的频率存在，并且它们响应于通过CD 16的信号传导而表现出增强的功能。这些细胞似乎代表了人类相当于适应性或“记忆”NK细胞在小鼠中，特异性地响应小鼠巨细胞病毒（MCMV）。由于它们的功能和存活特性，人们对能够利用它们进行免疫治疗有相当大的兴趣。在这 根据这项提议，我们的目标是使用无偏见的，尖端的深度测序方法研究microRNA在我们独特的移植患者NK细胞中HCMV再激活后适应性人类NK细胞分化中的作用。我们将测试这一假设，即通过激活受体的信号传导是适应性NK细胞扩增所必需的，并确定五聚体HCMV蛋白复合物和高亲和力抗体对这些复合物在触发扩增中的作用。我们有初步的数据表明，在HCMV诱导的适应性NK细胞中选择性诱导Notch/TCF-1和Wnt信号通路，我们将使用我们明确定义的移植队列和体外试验深入研究这两种通路在适应性NK细胞发育和分化中的作用。我们还将联合收割机结合我们最近开发的过继性人NK细胞转移的异种模型和小鼠中系统性HCMV感染的新模型来研究HCMV诱导的适应性NK细胞存活、归巢和体内功能。我们领先的基础和临床NK细胞生物学家，HCMV专家和小鼠免疫学家团队能够很好地进行这些研究，并将其转化为可以激发NK细胞有效功能和延长生存期的治疗方法，用于临床治疗癌症。

 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.