Targeting of RAG-dependent and -independent innate immune responses by the Ectromelia C15 protein

Ectromelia C15 蛋白靶向 RAG 依赖性和非依赖性先天免疫反应

基本信息

批准号：
10364738
负责人：
Laurence Crane Eisenlohr
金额：
$ 22万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-05 至 2023-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10364738
关键词：
Antibodies Attenuated B-Lymphocytes Biological Assay CD4 Positive T Lymphocytes CD8-Positive T-Lymphocytes CD8B1 gene Cell-Mediated Cytolysis Cells Communicable Diseases Cytolysis DNA Viruses Dangerousness Data Defense Mechanisms Development Disease Ectromelia Effector Cell Engineering Family Family member Flow Cytometry Future Goals Health Homologous Gene Host Defense Human Immune Immune Evasion Immune response In Vitro Infection Infectious Ectromelia Innate Immune Response Knock-out Lead Ligands Link Literature Lymphocyte Measures Mediating Memory Molecular Target Monkeypox Mouse Pox Virus Mus Natural Immunity Natural Killer Cells Orthopoxvirus Outcome Pathogenesis Phase Play Population Poxviridae Property Protein Family Proteins Public Health Recording of previous events Role Smallpox Smallpox Vaccine T-Cell Activation Techniques Testing Therapeutic Therapeutic Uses Vaccinia Vesicular stomatitis Indiana virus Viral Viral Proteins Virulence Virulence Factors Virulent Virus Virus Replication Work adaptive immunity base cell type experience immunological synapse immunoregulation in vivo insight member mouse model novel prevent receptor recruit replication factor A response

项目摘要

PROJECT SUMMARY Several members of the orthopoxvirus family, including variola (the cause of smallpox) and monkeypox, pose serious threats to human health. Other members are equally severe in their natural hosts, including ectromelia (ECTV), the cause of mousepox - a disease with many similarities to smallpox. The considerable virulence of these large DNA viruses is attributable in great measure to their many proteins that impede both innate and adaptive host defenses. The largest among these immunomodulatory proteins are the B22 family members, which, despite their size and contributions to virulence, remain vastly understudied. Highly homologous B22 family members are present throughout the orthopoxviruses except for vaccinia, the attenuated orthopoxvirus that has served as the smallpox vaccine for centuries. We focus in this exploratory R21 proposal on C15, the B22 family member of ECTV. Deletion of C15 converts the virus from 100% lethal to 100% nonlethal in vivo despite having no impact on replication in vitro. Our preliminary work with C15 has revealed two novel properties: 1) C15 potently and selectively inhibits CD4+ T cell activation in a way that inhibits assembly of the immunological synapse. 2) In addition to targeting adaptive immunity, C15 also facilitates viral replication as early as 3 days post infection, reflecting inhibition of innate immunity. Remarkably, C15 interferes with both RAG-dependent and -independent components of innate immunity. Based on our preliminary data and the established literature, we hypothesize that the RAG-independent component targeted by C15 is NK cell-mediated cytolysis and the RAG- dependent component is bystander activation of memory CD8+ T cells (Trm). We further hypothesize that the molecular target linking these two cell types is NKG2D, an activating receptor expressed by both NK cells and Trm and shown previously to play an important role in defense against ECTV. Drawing from many years of poxvirus experience and a wide range of established and cutting-edge techniques, we will test these three hypotheses in three independent but complementary aims. Outcomes of this project could considerably enhance understanding of orthopoxvirus pathogenesis and, more broadly, contribute to fundamental principles of virus:host interplay. In addition, we anticipate that results will launch several subsequent projects including: a) incorporation of CD4+ T cell inhibition in future mechanistic studies, b) examination of other B22 family members and, c) the development of C15 derivatives for potential therapeutic modulation of host responses.

项目概要正痘病毒家族的几个成员，包括天花（天花的病因）和猴痘，构成严重威胁人类健康。其他成员的自然宿主也同样严重，包括节肢症（ECTV），鼠痘的病因 - 一种与天花有许多相似之处的疾病。其毒力相当大这些大型 DNA 病毒在很大程度上归因于它们的许多蛋白质，这些蛋白质阻碍了先天和适应性宿主防御。这些免疫调节蛋白中最大的是 B22 家族成员，尽管它们的规模很大并且对毒力有贡献，但仍然没有得到充分的研究。高度同源的B22 家族成员存在于除牛痘（减毒正痘病毒）之外的所有正痘病毒中几个世纪以来，它一直被用作天花疫苗。我们重点关注 C15 的探索性 R21 提案， ECTV B22 家族成员。 C15 的缺失使病毒在体内从 100% 致死性转变为 100% 非致死性尽管对体外复制没有影响。我们对 C15 的初步研究揭示了两个新颖的特性： 1) C15 有效且选择性地抑制 CD4+ T 细胞活化，从而抑制免疫学组装突触。 2) 除了针对适应性免疫外，C15 还可促进病毒最早 3 天的复制感染后，反映先天免疫受到抑制。值得注意的是，C15 会干扰 RAG 依赖性和 -先天免疫的独立组成部分。根据我们的初步数据和现有文献，我们假设 C15 靶向的不依赖于 RAG 的成分是 NK 细胞介导的细胞溶解作用，而 RAG- 依赖成分是记忆 CD8+ T 细胞 (Trm) 的旁观者激活。我们进一步假设连接这两种细胞类型的分子靶标是 NKG2D，它是 NK 细胞和 NK 细胞表达的激活受体 Trm 先前已证明在防御 ECTV 方面发挥着重要作用。借鉴多年痘病毒经验和广泛的成熟和前沿技术，我们将测试这三个三个独立但互补的目标的假设。该项目的成果可以大大提高了解正痘病毒的发病机制，更广泛地说，有助于制定以下基本原则：病毒：宿主相互作用。此外，我们预计结果将启动几个后续项目，包括：a) 将 CD4+ T 细胞抑制纳入未来的机制研究中，b) 检查其他 B22 家族成员 c) 开发 C15 衍生物，用于宿主反应的潜在治疗调节。