The novel innate immune-antagonistic effects of ectromelia virus C15 protein

节肢动物病毒C15蛋白的新型先天免疫拮抗作用

基本信息

批准号：
10316985
负责人：
Elise Peauroi
金额：
$ 3.34万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10316985
关键词：
Adaptor Signaling Protein Binding Biological Assay Bioterrorism CD4 Positive T Lymphocytes Cell Count Cell physiology Cells Complex Coupled Cytolysis Data Dependence Disease Effector Cell Family Flow Cytometry Genes Goals Granzyme Homologous Gene Human IL2RG gene Immune Immune Targeting Immune response In Vitro Infection Infectious Ectromelia Innate Immune Response Investigation Knock-out Knockout Mice Knowledge Lead Leukocytes Ligands Link Literature Mediating Molecular Target Monkeypox Morbidity - disease rate Mouse Pox Virus Mus Natural Immunity Natural Killer Cells Organ Orthopoxvirus Pathogenesis Pathogenicity Phase Play Poxviridae Poxviridae Infections Production Protein Family Proteins Public Health Recording of previous events Role Smallpox Stains T cell response T-Cell Activation T-Lymphocyte TYROBP gene Testing Therapeutic Uses Time Viral Viral Genome Viral Proteins Virulence Virulence Factors Virulent Virus Virus Replication Work Zoonoses adaptive immunity arm cell type cytokine immune activation immunological synapse formation immunoregulation in vivo insight mortality novel protein function receptor replication factor A response success targeted treatment

项目摘要

PROJECT SUMMARY Smallpox was one of the deadliest diseases in human history, and despite its eradication, orthopoxviruses continue to pose a significant public health threat due to bioterrorism concerns and zoonoses. The virulence of these viruses relies upon their evasion of host immune responses by a large arsenal of immunomodulatory proteins. One of these proteins is the C15 protein of ectromelia virus, the cause of mousepox, which significantly impacts virulence in vivo. This protein is the largest in the viral genome and has homologs in the virulent orthopoxviruses, including the agents of smallpox and monkeypox, but no homology to any protein outside this family. Previous work has shown that C15 inhibits CD4 T cell activation, but I have recently determined that C15 significantly enhances viral replication in vivo at times that precede the onset of adaptive immunity, suggesting the existence of a second innate immune targeting function. The goal of this project is to understand this novel role of C15 early in infection. Preliminary work has shown that C15 maintains its replication-promoting effect in RAG KO but not RAG IL2RG double KO mice, implying the targeting of NK cells. Further analyses indicate C15 targeting of another RAG-dependent component of the innate immune response, most likely gd T cells. In searching for a unifying molecular target, additional preliminary data implicates the NK gene complex;; NKG2D is a receptor encoded within the NK complex that is capable of activating both NK cells and gd T cells. I therefore hypothesize that C15 inhibits NKG2D-mediated recognition of infected cells by NK and gd T cells, thereby inhibiting immune control of viral replication. To test this hypothesis, I propose three independent and complementary specific aims, each investigating the impact of C15 on one of the three components of the hypothesis. The first aim will identify the impact of C15 on NK cell function, using a set of orthogonal in vivo and in vitro approaches. The second aim will test the hypothesis that C15 targets gd T cells using similarly comprehensive approaches. The third aim will test the hypothesis that C15 targets NKG2D-mediated activation of immune cells by interrogating the importance of NKG2D and its adaptors DAP10 and DAP12 for the early impact of C15 in vivo as well as the impact of C15 on expression of NKG2D ligands. The identification of separate innate and adaptive immunomodulatory functions in a single viral protein is highly unique. The proposed studies will provide insight into the exceptional virulence of the orthopoxviruses, including those of particular public health concern, and could lead to the use of this protein family as an immune targeting therapeutic strategy.

项目概要天花是人类历史上最致命的疾病之一，尽管已被消灭，但正痘病毒由于生物恐怖主义问题和人畜共患病的毒力，继续对公共卫生构成重大威胁。这些病毒依靠大量的免疫调节来逃避宿主的免疫反应其中一种蛋白质是小鼠痘病毒的 C15 蛋白，它是引起鼠痘的病毒。该蛋白是病毒基因组中最大的，并且在体内具有同源物。剧毒正痘病毒，包括天花和猴痘病毒，但与任何蛋白质没有同源性在这个家族之外，之前的工作已经表明C15抑制剂可以激活CD4 T细胞，但我最近发现了这一点。确定 C15 在适应性出现之前的时间显着增强体内病毒复制免疫，表明存在第二个先天免疫靶向功能，该项目的目标是了解 C15 在感染早期的这种新作用。初步研究表明，C15 在 RAG KO 中保持其复制促进作用，但在 RAG 中则不然 IL2RG 双 KO 小鼠，意味着 NK 细胞的靶向。进一步分析表明 C15 靶向另一种细胞先天免疫反应的 RAG 依赖性成分，很可能是 gd T 细胞，正在寻找统一的 T 细胞。分子靶标，额外的初步数据表明 NK 基因复合体是编码的受体；因此，我推测 NK 复合物能够激活 NK 细胞和 gd T 细胞。 C15 抑制 NKG2D 介导的 NK 和 gd T 细胞对感染细胞的识别，从而抑制免疫控制病毒复制。为了检验这个假设，我提出了三个独立且互补的具体目标，每个目标都进行了调查。 C15 对假设的三个组成部分之一的影响第一个目标是确定以下因素的影响。 C15 对 NK 细胞功能的影响，使用一组正交的体内和体外方法进行测试。假设 C15 使用类似的综合方法靶向 gd T 细胞。假设 C15 通过询问 NKG2D 介导的免疫细胞激活的重要性 NKG2D及其适配器DAP10和DAP12对于C15体内的早期影响以及C15对体内的影响 NKG2D 配体的表达。单个病毒蛋白中单独的先天性和适应性免疫调节功能的鉴定是拟议的研究将提供对正痘病毒的特殊毒力的深入了解，包括那些具有特殊公共卫生问题的蛋白质，并可能导致使用该蛋白质家族作为免疫靶向治疗策略。