Viral and cellular mechanisms of HSV fusion and entry

HSV融合和进入的病毒和细胞机制

• 批准号: 10673420
• 负责人: ANTHONY V NICOLA
• 金额: $ 37.4万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10673420
• 关键词: Address; Biochemistry; Biological Assay; Blindness; Cell Culture Techniques; Cell fusion; Cell surface; Cells; Cellular biology; Chimeric Proteins; Clinical; Complex; Data; Defect; Development; Disease; Encephalitis; Endosomes; Epithelial Cells; Experimental Designs; Glycoproteins; Goals; Heparan Sulfate Proteoglycan; Heparitin Sulfate; Herpes Labialis; Herpesviridae; Herpesviridae Infections; Herpesvirus 1; Human; Immunocompromised Host; In Vitro; Infection; Integration Host Factors; Intervention; Knowledge; Laboratories; Lytic Phase; Mammalian Cell; Maps; Mediating; Mediator of activation protein; Membrane Fusion; Membrane Glycoproteins; Modeling; Molecular; Molecular Conformation; Molecular Virology; Morbidity - disease rate; Nature; Neonatal; Neurons; Outcome; PVRL1; Pathway interactions; Penetration; Play; Prevention; Process; Proteins; Recurrence; Regulation; Research; Role; Sexually Transmitted Diseases; Shapes; Simplexvirus; Site; Specificity; Structure; Surface; Techniques; Testing; Therapeutic; Time; Vaccines; Viral; Viral Envelope Proteins; Virus; Virus Diseases; Virus-Cell Membrane Interaction; antibody detection; cell type; env Gene Products; genital infection; human pathogen; inhibiting antibody; inhibitor; innovation; insight; latent infection; mortality; neonatal infection; novel; novel strategies; pathogen; prevent; receptor

Herpesviruses are ubiquitous pathogens that cause significant morbidity and mortality worldwide. Herpes simplex virus (HSV) causes cold sores and sexually transmitted infections. Grave outcomes of HSV infection include neonatal disease, blindness, and disseminated infections of the immunocompromised. Our long-term goal is a comprehensive understanding of the entry mechanisms of this important group of pathogens. Although much progress has been made, the complex mechanisms of herpesvirus fusion and entry remain enigmatic. This has posed a roadblock to developing clinically effective entry inhibitors. HSV enters most cultured mammalian cells and commandeers diverse entry pathways. An emerging concept in herpesvirology is that endosomal pH of the host cell is required for viral entry, often in a cell type specific manner. However, the mechanistic role that low pH plays in herpesviral entry is not clear. The HSV envelope proteins gB, gD, and the gH/gL heterodimer are required but are likely not sufficient for membrane fusion and entry in the context of HSV infection. Envelope protein gC is the principal mediator of viral attachment to cell surface heparan sulfate proteoglycans during entry. However, this interaction is dispensable for viral entry in cell culture and does not explain the infection defect of gC-deleted viruses. We recently revealed a new, post-attachment function for gC in HSV entry. gC influences the fusion protein gB and promotes efficient penetration of HSV from endosomes during entry. gC elevates the pH-threshold of fusion- associated conformational changes in the fusion protein gB. We formulated complementary yet independent aims to delineate previously unrecognized functions of HSV-1 gC. In Specific Aim 1, we will elucidate gC's role in fusion and entry by employing a battery of assays in the context of the required HSV envelope proteins and cellular receptors. Specific Aim 2 encompasses structure-function studies of gC pertinent to entry and infection of epithelial cells, the main target of primary and recurrent HSV infection. Our experimental design employs techniques of cell biology, biochemistry, and molecular virology. Completion of the aims will reveal detailed insight into the multifunctional nature of HSV-1 gC and will fill critical knowledge gaps about how the complex fusion mechanism of herpesviruses is triggered in pathophysiologically relevant cell types. These studies will aid in the development of new preventions and therapeutics for HSV.

疱疹病毒是普遍存在的病原体，在世界范围内引起显着的发病率和死亡率。单纯疱疹病毒 (HSV) 会引起唇疱疹和性传播感染。 HSV 感染的严重后果包括新生儿疾病、失明和免疫功能低下者的播散性感染。我们的长期目标是全面了解这一重要病原体的进入机制。尽管已经取得了很大进展，但疱疹病毒融合和进入的复杂机制仍然是个谜。这对开发临床上有效的进入抑制剂构成了障碍。 HSV 进入大多数培养的哺乳动物细胞并占据多种进入途径。疱疹病毒学中的一个新兴概念是，病毒进入需要宿主细胞的内体 pH 值，通常以细胞类型特异性的方式。然而，低pH值在疱疹病毒进入中所起的机制作用尚不清楚。 HSV 包膜蛋白 gB、gD 和 gH/gL 异二聚体是必需的，但在 HSV 感染的情况下可能不足以进行膜融合和进入。包膜蛋白 gC 是病毒进入细胞表面硫酸乙酰肝素蛋白聚糖时附着的主要介质。然而，这种相互作用对于病毒进入细胞培养物来说是可有可无的，并且不能解释 gC 缺失病毒的感染缺陷。我们最近在 HSV 条目中揭示了 gC 的一个新的附着后功能。 gC 影响融合蛋白 gB 并促进 HSV 在进入过程中从内体有效渗透。 gC 提高融合蛋白 gB 中融合相关构象变化的 pH 阈值。我们制定了互补但独立的目标来描述 HSV-1 gC 以前未被识别的功能。在具体目标 1 中，我们将通过在所需的 HSV 包膜蛋白和细胞受体的背景下采用一系列测定来阐明 gC 在融合和进入中的作用。具体目标 2 包括与上皮细胞进入和感染相关的 gC 的结构功能研究，上皮细胞是原发性和复发性 HSV 感染的主要目标。我们的实验设计采用细胞生物学、生物化学和分子病毒学技术。完成这些目标将揭示对 HSV-1 gC 多功能性质的详细了解，并将填补有关如何在病理生理相关细胞类型中触发疱疹病毒复杂融合机制的关键知识空白。这些研究将有助于开发新的 HSV 预防和治疗方法。