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

• 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
• 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

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.

项目摘要 正托病毒家族的几个成员，包括Variola（天花的原因）和Monkeypox，姿势 对人类健康的严重威胁。其他成员的天然寄主同样严重，包括胚胎 （ECTV），是摩西司毒素的原因 - 一种与天花有许多相似之处的疾病。相当大的毒力 这些大型DNA病毒在很大程度上归因于它们的许多蛋白质，这些蛋白质既妨碍了先天和 自适应主机防御。这些免疫调节蛋白中最大的是B22家庭成员， 尽管它们的规模和对毒力的贡献，但仍被大量研究。高度同源的B22 家庭成员在整个正ox病毒中都存在，除了疫苗外，正tenodecoxvirus 几个世纪以来一直用作天花疫苗。我们专注于有关C15的探索性R21提案 ECTV的B22家庭成员。 C15的缺失将病毒从100％致死到100％非致死性体内 尽管对体外复制没有影响。我们与C15的初步工作揭示了两个新型的特性： 1）C15有效并选择性地抑制CD4+ T细胞激活，以抑制免疫学的组装 突触。 2）除靶向适应性免疫外，C15还早在3天就促进了病毒复制 感染后，反映了对先天免疫的抑制。值得注意的是，C15干扰了rag依赖性和 - 天生免疫的独立组成部分。根据我们的初步数据和既定文献，我们 假设由C15靶向的抹布独立成分是NK细胞介导的胞解和rag- 依赖性成分是记忆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，这是NK细胞和NK细胞表达的激活受体 TRM并以前显示在防御ECTV中发挥重要作用。从多年 痘病毒的经验以及广泛的既定和尖端技术，我们将测试这三种 三个独立但互补的目标中的假设。该项目的结果可能会大大提高 对正托病毒发病机理的理解，更广泛地有助于 病毒：主机相互作用。此外，我们预计结果将启动几个随后的项目，包括：a） 在未来的机械研究中掺入CD4+ T细胞抑制作用，b）检查其他B22家族成员 c）C15衍生物的开发，用于宿主反应的潜在治疗调节。