Cellular and molecular mechanisms of NK cell suppression

NK细胞抑制的细胞和分子机制

• 批准号: 8043838
• 负责人: Yasmina Laouar
• 金额: $ 34.91万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-02 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8043838
• 关键词: Activated Natural Killer Cell; Adoptive Immunotherapy; Adoptive Transfer; Animal Model; Automobile Driving; Blood; Bone Marrow; Cell Count; Cell Survival; Cell Therapy; Cells; Clonal Expansion; Commit; Competence; Cytolysis; Cytoplasmic Granules; Data; Development; Face; Future; Galium; Genetic; Goals; Granzyme; Immune system; Immunotherapeutic agent; Immunotherapy; In Vitro; Infection; Knowledge; Leukocytes; Ligands; Lymph; Membrane; Messenger RNA; Molecular; Murid herpesvirus 1; Mus; Natural Killer Cells; Outcome; Outcome Study; Pathway interactions; Patients; Pattern; Population; Process; Production; Proliferating; Regulation; Research; Research Design; Resistance; Rest; Role; Signal Pathway; Signal Transduction; Staging; System; Testing; Time; Viral; Virus; Virus Diseases; Work; base; cancer cell; clinical application; combat; cytotoxic; cytotoxicity; design; improved; in vivo; in vivo Model; innovation; insight; killings; novel; programs; response; self-renewal

DESCRIPTION (provided by applicant): Natural Killer (NK) cells are the first line of defense against infection. During their lifetime, NK cells undergo dynamic processes: as they develop, NK cells commit, proliferate, differentiate, and then arrest. Once activated, they immediately acquire cytotoxicity and become quite rapacious in killing target cells. NK cells are predisposed to killing because they are programmed for that function during their development. Our long-term goal is to understand the regulatory mechanisms controlling NK cell dynamics as a prerequisite to the development of successful NK-cell based adoptive immunotherapy. Although the collective efforts, accumulated for the last 20 years, resulted in the identification of key positive regulators of NK cells, the current knowledge failed to identify or elucidate the mechanisms of NK cell negative regulation. We searched for potential candidates and successfully identified TGF? as a potent negative regulator of NK cells1. To date, TGF? remains the only identified negative regulator of NK cell number. Therefore, it is imperative that the mechanisms by which TGF? operate in NK cells are understood. The specific hypothesis driving the proposed research is that TGF? limits the production and restricts the cytotoxicity acquisition of NK cells in response to viral infection. This hypothesis is based on three preliminary data: First, lack of TGF?R signaling results in augmented production of NK cells at terminal differentiation in the bone marrow. Second, lack of TGF?R signaling revealed a previously undescribed population of Granzyme Blow NK cells which is otherwise suppressed in normal mice. Third, mice having TGF?-resistant Granzyme Blow NK cells are resistant to murine cytomegalovirus. Using a combination of in vitro and in vivo approaches, we will test our hypothesis in two Specific Aims: In Aim 1, we will determine the mechanisms by which TGF? controls the production of NK cells. Two studies are designed to investigate i)-how TGF? regulates the processes of differentiation, survival, and proliferation during the production of NK from the bone marrow, and i)-why NK cells at their terminal differentiation are particularly susceptible to TGF? signaling. One prerequisite for the development of successful NK-cell-based immunotherapy in the future is to determine the factors that condition the survival, expansion, and self renewal of NK cells. The possibility that a lack of TGF?R signaling can prolong NK cell survival will support the notion that blocking the TGF?R pathway in NK cells prior to adoptive transfer into patients is a possibility for improving the design of NK-cell-based immunotherapeutic strategies. In Aim 2, we will determine the mechanism by which TGF? restricts functional competence of NK cells during response infection. Three studies were designed to determine direct outcomes of a lack of TGF?R signaling on i)- acquisition of cytotoxicity, ii)-clonal expansion and contraction in response to viral infection, and iii)-tolerance to viral ligands. We believe that understanding how negative regulation by TGF? restricts NK cell cytotoxicity will provide a strategy to make NK cells stronger in facing evolving viruses. PUBLIC HEALTH RELEVANCE: A type of white blood cells called Natural Killer (NK) cells may hold the key to combating infection. First discovered in the 1980's, NK cells are recognized as the immune system's front-line defense against infection. Circulating through the body by way of the blood and lymph systems, the majority of NK cells present in the body are in a resting state. Once activated, NK cells become quite rapacious in their search-and-destroy activities. Upon encountering a target cell (an infected cell or cancer cell), the activated NK cell attaches to the membrane of the target cell and injects cytoplasmic granules that quickly dissolve (lyse) the target cell. In less than five minutes, the infected or cancer cell is dead and the NK cell moves on to its next target. A single NK cell can destroy up to 27 target cells before it dies. The importance of NK cells in combating infection is undisputable but viruses are cleaver because they have evolved mechanisms for modulating NK cell activity to persist in spite of an active host immune system. That means we need to develop stronger NK cells to face the evolving viruses. In this research, we propose to study the function of "super"-NK cells developed to be stronger in killing infected cells. These super-NK cells were generated by genetic blockage of TGF? signaling pathway which renders them resistant to TGF? action. They will be called "TGF?-resistant NK cells". Studying the "super" killing functions of TGF?-resistant NK cells is the major goal of this project. Overall, this comprehensive study has a strong potential of clinical applicability. It is novel because it is one of a very few studies to directly assess in vivo the role of TGF? in NK cells, and it is innovative because it uses a unique in vivo model. Outcomes of the project are expected to generate new insight into the fundamental knowledge of NK cells and likely will provide a promising strategy to improve current NK cell- based immunotherapies.

描述(申请人提供)：自然杀伤(NK)细胞是抵御感染的第一道防线。在其一生中，NK细胞经历了动态的过程：随着它们的发育，NK细胞承诺、增殖、分化，然后停止。一旦被激活，它们就会立即获得细胞毒性，并变得非常贪婪地杀死目标细胞。NK细胞易于杀伤，因为它们在发育过程中被编程为具有这一功能。我们的长期目标是了解控制NK细胞动力学的调控机制，以此作为发展成功的基于NK细胞的过继免疫治疗的先决条件。尽管经过近20年的共同努力，人们已经发现了NK细胞的关键正调控因子，但目前的认识未能明确或阐明NK细胞负调控的机制。我们寻找了潜在的候选者，并成功地鉴定出了转化生长因子？作为NK细胞的有效负性调节因子1。到目前为止，是不是，转化生长因子？仍然是唯一已发现的NK细胞数量的负调节因子。因此，研究转化生长因子？在NK细胞中的作用已被了解。推动这项研究的具体假设是：转化生长因子？限制NK细胞的产生和细胞毒作用的获得，以应对病毒感染。这一假说基于三个初步数据：第一，缺乏转化生长因子受体信号导致骨髓在终末分化时NK细胞的产生增加。其次，缺乏转化生长因子受体信号，揭示了一个以前未被描述的颗粒酶Blow NK细胞群体，否则在正常小鼠中被抑制。第三，具有抗转化生长因子的颗粒酶BLOW NK细胞的小鼠对小鼠巨细胞病毒具有抵抗力。使用体外和体内相结合的方法，我们将在两个特定的目标上检验我们的假设：在目标1中，我们将确定转化生长因子？控制NK细胞的产生。两项研究旨在调查i)--转化生长因子如何？调节从骨髓产生NK过程中的分化、存活和增殖过程，以及i)为什么NK细胞在其终末分化时特别容易受到转化生长因子的影响？发信号。未来以NK细胞为基础的免疫治疗的成功发展的前提之一是确定影响NK细胞存活、扩增和自我更新的因素。缺乏转化生长因子受体信号可以延长NK细胞存活的可能性将支持这样一种观点，即在过继转移到患者体内之前阻断NK细胞中的转化生长因子受体通路是改进基于NK细胞的免疫治疗策略设计的可能性。在目标2中，我们将确定转化生长因子？在应答感染过程中限制NK细胞的功能。三项研究旨在确定缺乏转化生长因子受体信号的直接结果：i)获得细胞毒性，ii)对病毒感染的克隆性扩张和收缩，以及iii)对病毒配体的耐受性。我们认为，理解转化生长因子的负面调控是如何实现的？限制NK细胞的细胞毒作用将提供一种策略，使NK细胞在面对不断进化的病毒时变得更强大。 与公共卫生相关：一种名为自然杀伤(NK)细胞的白细胞可能是对抗感染的关键。NK细胞最早发现于20世纪80年代的S，被认为是免疫系统抵御感染的前线防御细胞。通过血液和淋巴系统在体内循环，体内存在的大多数NK细胞处于休眠状态。一旦被激活，NK细胞就会变得非常贪婪地进行搜索和摧毁活动。当遇到靶细胞(受感染的细胞或癌细胞)时，激活的NK细胞附着在靶细胞的膜上，并注射细胞质颗粒，迅速溶解(溶解)靶细胞。在不到五分钟的时间里，受感染的细胞或癌细胞就会死亡，NK细胞就会转移到下一个目标。单个NK细胞可以在死亡前摧毁多达27个目标细胞。NK细胞在对抗感染中的重要性是毋庸置疑的，但病毒更为重要，因为它们进化出了调节NK细胞活性的机制，使其在宿主免疫系统活跃的情况下仍能持续存在。这意味着我们需要培养更强大的NK细胞来应对不断演变的病毒。在这项研究中，我们建议研究“超级”-NK细胞在杀伤感染细胞方面的功能。这些超自然杀伤细胞是通过基因阻断转化生长因子？是什么信号通路使它们对转化生长因子产生抵抗？行动。它们将被称为“抗转化生长因子的自然杀伤细胞”。研究抗转化生长因子的NK细胞的“超级”杀伤功能是该项目的主要目标。总体而言，本研究具有较强的临床应用潜力。它之所以新颖，是因为它是为数不多的直接在体内评估转化生长因子的作用的研究之一。在NK细胞中，它是创新的，因为它使用了一个独特的体内模型。该项目的成果有望对NK细胞的基础知识产生新的见解，并可能为改进目前基于NK细胞的免疫疗法提供一种有前途的战略。