Structure, antigenicity, and function of HCMV fusogen gB

HCMV融合剂gB的结构、抗原性和功能

• 批准号: 10424572
• 负责人: Ekaterina Heldwein
• 金额: $ 75.86万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-08 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10424572
• 关键词: Antibodies; Antibody Response; Antigens; B-Lymphocytes; Binding; Biochemical; CMV glycoprotein B; Cell membrane; Cells; Closure by clamp; Complex; Cryoelectron Microscopy; Cytomegalovirus; Cytomegalovirus Infections; Cytomegalovirus Vaccines; Cytoplasmic Tail; Data; Development; Disease; Engineering; Epitopes; Fetus; Frequencies; Glycoproteins; Goals; Herpesviridae; Host Defense; Human; Human Herpesvirus 4; Immune response; Immunocompromised Host; Infection; Knowledge; Lead; Life; Mediating; Membrane; Membrane Fusion; Memory B-Lymphocyte; Molecular Conformation; Molecular Machines; Mothers; Nature; Passive Immunization; Penetration; Population; Preparation; Prevent viral transmission; Property; Proteins; Reagent; Regulatory Element; Research; Resolution; Role; Side; Simplexvirus; Site; Sorting - Cell Movement; Structure; Testing; Time; Translational Research; Transplant Recipients; Vaccines; Viral; Work; design; human pathogen; immunogenic; innovation; knowledge of results; neonate; neutralizing antibody; novel; prophylactic; receptor; research and development; response; seropositive; stem; tool; vaccination strategy; vaccine candidate; vaccine development

PROJECT SUMMARY/ABSTRACT Human cytomegalovirus (HCMV) is a highly successful human pathogens that infects much of the world’s population for life. While often asymptomatic, HCMV infections can cause severe disseminated disease in immunocompromised patients, e.g., transplant recipients, and developmental abnormalities in neonates. Hence, there is an urgent need for prophylactics to prevent viral transmission, especially from mother to fetus. HCMV glycoprotein B (gB) is both a key viral penetration protein and a dominant antigen for host defense. Unsurprisingly, gB is a component of all current HCMV vaccine candidates. However, vaccine efforts are stymied, at least in part, by an incomplete understanding of gB-specific immune responses. Moreover, the mechanistic contributions of gB to membrane fusion require further clarification. These gaps in our knowledge of both gB function and antigenicity largely stem from the reliance of research on the inactive, postfusion form of gB that cannot adequately recapitulate the active, prefusion form. We have successfully engineered soluble HCMV gB ectodomain in a prefusion form. Here, we propose to characterize its structure, antigenicity, and the mechanisms that control its activity. In Aim 1, we will determine the high-resolution structures of the prefusion HCMV gB and its complexes with known neutralizing antibodies. We will also stabilize prefusion gB for downstream applications (biochemical research and immunogen development). In Aim 2, we will isolate and characterize prefusion-gB-specific neutralizing antibodies from HCMV-seropositive donors. In Aim 3, we will investigate the regulatory mechanism that may restrain gB in its prefusion form. The proposal is innovative because, to our knowledge, this is the first time the soluble prefusion form of HCMV gB was successfully engineered. The proposal is significant because it will yield new mechanistic knowledge and provide new reagents that could aid in the development of optimal vaccines and passive immunization strategies against HCMV.

项目概要/摘要 人类巨细胞病毒 (HCMV) 是一种非常成功的人类病原体，可感染世界上大部分地区 终生人口。 HCMV 感染虽然通常无症状，但可在人体中引起严重的播散性疾病。 免疫功能低下的患者，例如移植受者，以及新生儿发育异常。 因此，迫切需要预防剂来防止病毒传播，特别是从母亲到胎儿的传播。 HCMV 糖蛋白 B (gB) 既是关键的病毒渗透蛋白，也是宿主防御的显性抗原。 毫不奇怪，gB 是目前所有 HCMV 候选疫苗的组成部分。然而，疫苗工作正在 对 gB 特异性免疫反应的不完全理解至少部分地阻碍了这一研究。此外， gB 对膜融合的机制贡献需要进一步阐明。我们知识中的这些差距 gB 功能和抗原性的研究很大程度上源于对非活性、融合后形式的研究的依赖 gB 不能充分概括活跃的预融合形式。我们已经成功设计了 预融合形式的可溶性 HCMV gB 胞外域。在这里，我们建议表征其结构， 抗原性以及控制其活性的机制。在目标 1 中，我们将确定高分辨率 融合前 HCMV gB 及其与已知中和抗体的复合物的结构。我们还将 稳定预融合 gB 以用于下游应用（生化研究和免疫原开发）。在 目标 2，我们将从 HCMV 血清阳性中分离并表征融合前 gB 特异性中和抗体 捐助者。在目标 3 中，我们将研究可能抑制 gB 预融合形式的调控机制。这 该提案具有创新性，因为据我们所知，这是首次采用可溶性预灌注形式的 HCMV gB 被成功设计。该提案意义重大，因为它将产生新的机械知识和 提供有助于开发最佳疫苗和被动免疫的新试剂 对抗 HCMV 的策略。