Lipid/DNA/Antigen Complexes for Influenza A Viral Vaccination

描述（由申请人提供）：甲型流感（fluA）感染每年在世界范围内引起大量发病率和死亡率，特别是对婴儿，老年人和免疫功能低下者。流感病毒主要在呼吸道复制，毒性毒株也会传播到其他组织，如中枢神经系统。令人日益关切的是，最近H5N1等致病性禽流感病毒在亚洲的传播可能大大增加人间大流行的风险。最近发生了禽流感经人传播的散发病例，死亡率很高。由于流感病毒易于进行基因重组和由重组DNA产生，并通过暴露于呼吸道分泌物而迅速传播，因此流感病毒也是一种潜在的生物威胁剂。目前的疫苗，如经鼻给药的三价灭活疫苗（TIV）或减毒活疫苗（LIV），诱导最低或中等水平的细胞溶解t淋巴细胞（CTL）活性，并主要通过产生CD4 t细胞依赖性中和抗体来提供保护。这些疫苗的效力高度依赖于疫苗的血凝素（HA）和神经氨酸酶（NA）表面蛋白与当前流行的病毒的密切匹配。如果中和抗体不能阻止呼吸道感染，后续病毒感染的清除主要依赖于T细胞，尤其是CTL。Juvaris BioTherapeutics正在开发和鉴定一种独特的佐剂，特别有希望用于诱导高水平抗体和t细胞免疫（包括CTL）的疫苗。这种佐剂是基于脂质载体和非编码DNA （CLDC）的复合物，通过多种途径有效，包括肠外注射、呼吸和口服。CLDC中包含的蛋白抗原导致体液和CD4和CDS t细胞对模型抗原（如卵白蛋白或蛾细胞色素c）以及针对呼吸道的病原体抗原（如鼠疫耶尔森氏菌和结核分枝杆菌）产生极其强大的应答。某些疫苗接种途径，如腹腔和口服给药，可导致肺中CTL的显著水平。本建议的具体目标是优化CLDC-疫苗系统在体内，特别是在肺中的甲型流感特异性t细胞反应。这种最佳配方将用于评估对小鼠减毒甲型流感毒株（HKx31和PR/8/34）以及最近高毒力的H5N1禽流感病毒分离株的鼻内攻击的保护作用。一个主要的重点将是比较仅基于对内部病毒粒子蛋白的t细胞免疫的疫苗效力与这些反应结合对外部蛋白质的抗体所提供的疫苗效力。如果成功，第二阶段将审查疫苗的潜在生产方法和大型动物功效研究。

DESCRIPTION (provided by applicant): Influenza A (fluA) infection causes annual substantial morbidity and mortality worldwide, particularly for infants, the elderly, and the immuncompromised. FluA mainly replicates in the respiratory tract, with virulent strains also disseminating to other tissues, such as the central nervous system. A growing concern is the recent spread of virulent avian influenza viruses, such as H5N1, in Asia, which could substantially increase the risk of a human pandemic. Sporadic cases of avian-to-human transmission, with a high mortaility rate have recently occurred. Because of its ability to readily undergo genetic reassortment and be generated by recombinant DNA, and to be rapidly spread by exposure to respiratory secretions, FluA is also a potential biothreat agent. Current vaccines, such as the parenterally administered trivalent inactivated vaccine (TIV) or live attenuated vaccine (LIV) given intranasally, induce minimal or modest levels of cytolytic T-lymphocyte (CTL) activity, and provide protection mainly by the production of CD4 T-cell dependent neutralizing antibodies. The efficacy of these vaccines is highly dependent on close matching of the hemagglutinin (HA) and neuraminidase (NA) surface proteins of the vaccine with currently circulating virus. Should neutralizing antibody fail to prevent infection of the respiratory tract, subsequent clearance of viral infection is mainly dependent on T cells, particularly CTL. Juvaris BioTherapeutics is developing and characterizing a unique adjuvant that is particularly promising for vaccines that induce both high levels of antibody and T-cell immunity, including CTL. The adjuvant is based on a complex of lipid carrier and non-coding DNA (CLDC), and is effective via multiple routes, including parenteral, respiratory, and oral. Inclusion of protein antigens with CLDC results in an extremely robust humoral and CD4 and CDS T-cell response to model antigens, such as ovalbumin or moth cytochrome c, as well as antigens from pathogens that target the respiratory tract, such as Yersinia pestis and Mycobacterium tuberculosis. Certain vaccination routes, such as intraperitoneal and oral administration results in particularly striking levels of CTL in the lung. The specific goals of this proposal are to optimize the CLDC- vaccine system for influenza A-specific T-cell responses in vivo, particularly in the lung. This optimal formulation will be used to evaluate protection against intranasal challenges with mouse attenuated influenza A strains (HKx31 and PR/8/34) as well as highly virulent recent isolate strains of avian H5N1 virus. A major focus will be in comparing vaccine efficacy based solely on T-cell immunity to internal virion proteins with that afforded by these responses in combination with antibody to external proteins. If successful, Phase II will examine potential manufacturing methods for the vaccine and large animal efficacy studies.