Preclinical Studies of Vaccines for Pandemic H1N1 Influenza

大流行性 H1N1 流感疫苗的临床前研究

• 批准号: 8745537
• 负责人: Kanta Subbarao
• 金额: $ 152.12万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8745537
• 关键词: Animals; Antibodies; Antigen Presentation; Antigenic Variation; Antigens; Antiviral Agents; Base Sequence; Binding; Birds; Centers for Disease Control and Prevention (U.S.); Collaborations; Computing Methodologies; Data; Development; Disease; Epidemic; Epitopes; Family suidae; Hemagglutinin; Histocompatibility Antigens Class I; Human; Immune; Immune response; Individual; Infection; Influenza; Influenza A Virus, H1N1 Subtype; Influenza A virus; Ligand Binding; Ligands; Location; Lung; Maps; Membrane; Membrane Glycoproteins; Membrane Proteins; Molecular; Morbidity - disease rate; Mus; Neuraminidase; Peptides; Physiologic pulse; Population; Proteins; Reporting; Resistance; Severity of illness; Structure; Surface; System; T cell response; Technology; Testing; United States; Vaccine Design; Vaccines; Viral; Virion; Virus; Virus Diseases; Virus Replication; World Health Organization; aquatic bird; base; cytokine; density; disorder prevention; influenza virus vaccine; influenzavirus; injured; mortality; mouse model; neutralizing antibody; novel; pandemic disease; pandemic influenza; preclinical study; prevent; response; stem; three dimensional structure; tomography

There is a need for alternative or adjunct therapies for influenza, because resistance to currently used antiviral drugs can emerge rapidly. In collaboration with CEL-SCI Corporation, we tested a ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2 -microglobulin chain of the human MHC class I molecule (J-LEAPS) with 15 to 30 amino acidlong peptides derived from influenza virus NP, M, or HA proteins. DCs were stimulated with influenza-J-LEAPS peptides (influenza-J-LEAPS) and injected intravenously into infected mice. Antigen-specific LEAPS stimulated DCs were effective in reducing influenza virus replication in the lungs and enhancing survival of infected animals. Additionally, they augmented influenza-specific T cell responses in the lungs and reduced the severity of disease by limiting excessive cytokine responses, which are known to contribute to morbidity and mortality following influenza virus infection. Our data demonstrated that influenza-J-LEAPS pulsed DCs reduce virus replication in the lungs, enhance survival, and modulate the protective immune responses that eliminate the virus while preventing excessive cytokines that could injure the host. This approach shows promise as an adjunct to antiviral treatment of influenza virus infections. Rapid antigenic variation of HA, the major virion surface protein of influenza A virus, remains the principal challenge to the development of broader and more effective vaccines. Some regions of HA, such as the stem region proximal to the viral membrane, are nevertheless highly conserved across strains and among most subtypes. A fundamental question in vaccine design is the extent to which HA stem regions on the surface of the virus are accessible to broadly neutralizing antibodies. In collaboration with Sriram Subramaniams lab from NCI, we reported 3D structures derived from cryoelectron tomography of HA on intact 2009 pandemic H1N1 virions in the presence and absence of the antibody C179, which neutralizes viruses expressing a broad range of HA subtypes, including H1, H2, H5, H6, and H9. By fitting previously derived crystallographic structures of trimeric HA into the density maps, we deduced the locations of the molecular surfaces of HA involved in interaction with C179. Using computational methods to distinguish individual unliganded HA trimers from those that have bound C179 antibody, we demonstrated that ∼75% of HA trimers on the surface of the virus have C179 bound to the stem domain. Thus, despite their close packing on the viral membrane, the majority of HA trimers on intact virions are available to bind anti-stem antibodies that target conserved HA epitopes, establishing the feasibility of universal influenza vaccines that elicit such antibodies.

流感需要替代疗法或辅助疗法，因为对目前使用的抗病毒药物的耐药性可能会迅速出现。我们与 CEL-SCI Corporation 合作，在小鼠模型中测试了配体表位抗原呈递系统 (LEAPS) 技术，作为一种基于免疫的新型流感病毒感染治疗方法。流感-J-LEAPS 肽是通过将源自人 MHC I 类分子 (J-LEAPS) 的 β2-微球蛋白链的结合配体与源自流感病毒 NP、M 或 HA 蛋白的 15 至 30 个氨基酸长的肽缀合来合成的。 DC用流感-J-LEAPS肽（流感-J-LEAPS）刺激并静脉注射到受感染的小鼠体内。抗原特异性LEAPS刺激的DC可有效减少流感病毒在肺部的复制并提高受感染动物的存活率。此外，它们还增强了肺部的流感特异性 T 细胞反应，并通过限制过度的细胞因子反应来降低疾病的严重程度，众所周知，细胞因子反应会导致流感病毒感染后的发病率和死亡率。我们的数据表明，流感-J-LEAPS 脉冲 DC 可以减少病毒在肺部的复制，提高存活率，并调节保护性免疫反应，消除病毒，同时防止可能伤害宿主的过量细胞因子。这种方法显示出作为流感病毒感染抗病毒治疗的辅助手段的前景。 HA（甲型流感病毒的主要病毒粒子表面蛋白）的快速抗原变异仍然是开发更广泛和更有效的疫苗的主要挑战。然而，HA 的某些区域，例如接近病毒膜的茎区域，在不同毒株和大多数亚型中是高度保守的。疫苗设计中的一个基本问题是病毒表面的 HA 干区在多大程度上可被广泛中和抗体所接近。我们与 NCI 的 Sriram Subramaniams 实验室合作，报道了在存在和不存在抗体 C179 的情况下，对完整的 2009 年大流行 H1N1 病毒粒子进行 HA 的冷冻电子断层扫描得出的 3D 结构，C179 可以中和表达多种 HA 亚型（包括 H1、H2、H5、H6 和 H9）的病毒。通过将先前导出的三聚 HA 晶体结构拟合到密度图中，我们推断出参与与 C179 相互作用的 HA 分子表面的位置。使用计算方法将单个未配体的 HA 三聚体与已结合 C179 抗体的 HA 三聚体区分开来，我们证明病毒表面上约 75% 的 HA 三聚体的 C179 与干结构域结合。因此，尽管它们紧密堆积在病毒膜上，但完整病毒体上的大多数 HA 三聚体可结合针对保守 HA 表位的抗干抗体，从而确立了引发此类抗体的通用流感疫苗的可行性。