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，因为对当前使用的抗病毒药物可能会迅速产生耐药性。在与CEL-SCI公司的合作下，我们测试了一种配体表位抗原呈递系统(LEAPS)技术，作为一种新的基于免疫的治疗流感病毒感染的小鼠模型。流感-J-LEAPS多肽是由人MHC-I类分子(J-LEAPS)的2-微球蛋白链与来自流感病毒NP、M或HA蛋白的15-30个氨基酸酸长的多肽偶联而成。用流感-J-LEAPS多肽(流感-J-LEAPS)刺激DC，并静脉注射到感染小鼠体内。抗原特异性跃迁刺激的DC能有效减少流感病毒在肺部的复制，提高感染动物的存活率。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性，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-LEAP冲击的DC减少了病毒在肺部的复制，提高了存活率，并调节了保护性免疫反应，从而消除了病毒，同时防止了可能损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的抗病毒治疗的辅助手段的前景。 甲型流感病毒的主要病毒粒子表面蛋白HA抗原的快速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，如病毒膜近端的茎区域，在不同毒株和大多数亚型之间高度保守。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以被广泛中和抗体所获得。与NCI的Sriram Subramaniams实验室合作，我们报告了在存在和不存在抗体C179的情况下，通过对完整的2009年大流行H1N1病毒粒子进行冷冻电子断层扫描获得的HA的3D结构，该抗体中和了表达多种HA亚型的病毒，包括H1、H2、H5、H6和H9。通过将先前得到的三聚体HA的晶体结构与密度图进行拟合，我们推导出与C179相互作用的HA分子表面的位置。使用计算方法区分单独的未连接的HA三聚体和那些结合了C179抗体的三聚体，我们证明了病毒表面75%的HA三聚体与干区结合了C179。因此，尽管它们紧密地堆积在病毒膜上，但完整病毒粒子上的大多数HA三聚体都可与针对保守的HA表位的抗干抗体结合，从而确立了产生此类抗体的通用流感疫苗的可行性。