Defining the role of natural killer cells in COVID-19

定义自然杀伤细胞在 COVID-19 中的作用

• 批准号: 10756069
• 负责人: Madeline Jane Lee
• 金额: $ 4.07万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-06 至 2025-06-05
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10756069
• 关键词: 2019-nCoV; Activated Natural Killer Cell; Acute; Affect; Automobile Driving; Biological Assay; COVID-19; COVID-19 impact; COVID-19 mortality; COVID-19 patient; COVID-19 severity; Cell Communication; Cells; Cellular biology; Coculture Techniques; Data; Disease; Down-Regulation; Functional disorder; Future; Immune; Immune Evasion; Immune response; Immune system; Impairment; In Vitro; Knowledge; Ligands; Lung; Measures; Mediating; Mediator; NK Cell Activation; Natural Killer Cells; Pathogenesis; Pathologic; Pathology; Patients; Peripheral; Phenotype; Play; Predisposition; Qualifying; Receptor Cell; Research; Role; SARS-CoV-2 infection; Severities; Severity of illness; System; Testing; Therapeutic; Tumor Immunity; Vaccination; Viral; Viral Physiology; Virus Diseases; Work; biosafety level 3 facility; cell killing; cell type; cohort; cytotoxic; cytotoxicity; exhaust; exhaustion; experimental study; insight; migration; monocyte; prevent; receptor; response; severe COVID-19; therapeutic development; tumor; virology

PROJECT SUMMARY Severe COVID-19 induces strong alterations in the peripheral immune system. Some immune cell types take on a protective role in this disease, while others contribute to disease pathology. One cell type whose functional role in COVID-19 is not yet known is the natural killer (NK) cell. I previously demonstrated that NK cells, which can mediate antiviral activity, are strongly altered by severe COVID-19. I have also generated preliminary data demonstrating that SARS-CoV-2 modulates the expression of ligands for the NK cell activating receptor NKG2D and allows infected cells to avoid NK cell killing; however, the mechanisms underlying this remain unexplored. Moreover, although the NK cells of COVID-19 patients are poor mediators of cytotoxicity against tumor target cells, the functional responses of NK cells from COVID-19 patients to SARS-CoV-2-infected cells have not been examined. The proposed research seeks to resolve these critical gaps in our knowledge of the immune response to SARS-CoV-2 by investigating the mechanisms underlying the phenotype and function of NK cells in COVID-19. To do this, I will 1) Define the mechanisms by which SARS-CoV-2 modulates NK cell responses; 2) Characterize the functional responses of NK cells from COVID-19 patients with a wide range of disease severities against target cells infected with SARS-CoV-2; and 3) Elucidate the role of monocyte-NK cell crosstalk in driving NK cell exhaustion in severe COVID-19. I hypothesize that the experiments described in my proposal will show that prolonged stimulation of peripheral NK cells by monocytes contributes to exhaustion in the NK cells of severe COVID-19 patients, driving poor functional responses against SARS-CoV-2-infected target cells that are exacerbated by immune evasion mechanisms mediated by SARS-CoV-2. To test this hypothesis, I will utilize NK cells and monocytes from a large cohort of COVID-19 patients with disease severities ranging from mildly symptomatic to fatal. I will perform functional assays that test the responses of these NK cells against target cells infected with replication-competent SARS-CoV-2 in Stanford’s BSL3 facilities. I will also assess the ability of monocytes from severe COVID-19 patients to induce activation and exhaustion in healthy NK cells by establishing a co-culture system with these two cell types. Overall, my experiments will uncover the basis for the NK cell phenotype observed in COVID-19, the effects of this phenotype on NK cell responses to SARS-CoV-2-infected cells, and the mechanisms by which SARS-CoV-2 modulates the susceptibility of infected cells to NK cell cytotoxicity. Thoroughly interrogating the responses of NK cells to SARS-CoV-2 will help to determine whether the role of NK cells in COVID-19 is protective or pathological and will further our collective understanding of NK cell biology. Moreover, the identification of receptors involved in the modulation of NK cell activation will inform the development of therapeutic strategies for COVID-19.

项目摘要 严重的COVID-19会诱导外周免疫系统发生强烈变化。一些免疫细胞类型 在这种疾病中起保护作用，而另一些则有助于疾病病理学。一种细胞类型， 在COVID-19中的功能作用尚不清楚的是自然杀伤（NK）细胞。我之前证明了NK 可以介导抗病毒活性的细胞被严重的COVID-19强烈改变。我还生成了 初步数据表明，SARS-CoV-2调节NK细胞活化配体的表达， 受体NKG 2D，并允许感染的细胞，以避免NK细胞杀伤;然而，这背后的机制， 仍然未被探索。此外，尽管COVID-19患者的NK细胞是细胞毒性的不良介质， 针对肿瘤靶细胞，来自COVID-19患者的NK细胞对 SARS-CoV-2感染的细胞尚未被检测。这项研究旨在解决这些关键问题。 通过研究SARS-CoV-2免疫应答的机制， NK细胞在COVID-19中的表型和功能。为了做到这一点，我将1）定义机制， SARS-CoV-2调节NK细胞应答; 2）表征来自SARS-CoV-2的NK细胞的功能应答。 针对感染SARS-CoV-2的靶细胞的疾病严重程度范围广泛的COVID-19患者;以及 3)阐明单核细胞-NK细胞串扰在严重COVID-19中驱动NK细胞耗竭的作用。我 假设我的建议中描述的实验将表明，外周神经的长时间刺激 单核细胞的NK细胞导致严重COVID-19患者的NK细胞衰竭， 免疫逃避加剧了针对SARS-CoV-2感染靶细胞的功能反应 SARS-CoV-2介导的机制。为了验证这一假设，我将利用NK细胞和单核细胞从一个 一大群COVID-19患者，疾病严重程度从轻度症状到致命不等。我会 进行功能性测定，测试这些NK细胞对感染的靶细胞的反应， 在斯坦福大学的BSL 3设施中复制有能力的SARS-CoV-2。我还将评估单核细胞的能力， 严重的COVID-19患者通过建立共培养物诱导健康NK细胞的活化和耗竭 这两种细胞类型。总之，我的实验将揭示NK细胞表型的基础 在COVID-19中观察到，这种表型对NK细胞对SARS-CoV-2感染细胞的反应的影响，以及 SARS-CoV-2调节感染细胞对NK细胞毒性敏感性的机制。 彻底探究NK细胞对SARS-CoV-2的反应将有助于确定 COVID-19中的NK细胞是保护性的还是病理性的，这将进一步加深我们对NK细胞的集体理解 生物学此外，参与调节NK细胞活化的受体的鉴定将为NK细胞活化提供信息。 制定COVID-19治疗策略。