Lipid/DNA/Antigen Complexes for Influenza A Viral Vaccination

描述（由申请方提供）：甲型流感（fluA）感染每年在全球范围内导致大量发病率和死亡率，特别是婴儿、老年人和免疫功能低下者。FluA主要在呼吸道中复制，强毒株也传播到其他组织，如中枢神经系统。一个日益令人关切的问题是，H5 N1等烈性禽流感病毒最近在亚洲蔓延，这可能大大增加人类大流行病的风险。最近发生了禽传人的零星病例，死亡率很高。由于其易于进行基因重组并由重组DNA产生的能力，以及通过暴露于呼吸道分泌物而迅速传播的能力，FluA也是一种潜在的生物威胁剂。目前的疫苗，如肠胃外施用的三价灭活疫苗（TIV）或鼻内给予的减毒活疫苗（LIV），诱导最小或中等水平的细胞溶解性T淋巴细胞（CTL）活性，并主要通过产生CD 4 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病毒的紧密匹配。如果中和抗体不能预防呼吸道感染，随后的病毒感染清除主要依赖于T细胞，特别是CTL。Juvaris BioTherapeutics正在开发和表征一种独特的佐剂，这种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。该佐剂基于脂质载体和非编码DNA（CLDC）的复合物，并且通过多种途径有效，包括肠胃外、呼吸道和口服。将蛋白抗原与CLDC包含在一起导致对模型抗原（例如卵清蛋白或蛾细胞色素c）以及来自靶向呼吸道的病原体（例如鼠疫耶尔森氏菌和结核分枝杆菌）的抗原的极其稳健的体液和CD 4和CDS T细胞应答。某些疫苗接种途径，如腹膜内和口服给药导致肺中特别显著的CTL水平。该提案的具体目标是优化CLDC疫苗系统，用于体内，特别是肺中的甲型流感特异性T细胞应答。该最佳制剂将用于评价对小鼠减毒甲型流感病毒株（HKx 31和PR/8/34）以及禽H5 N1病毒高毒力最近分离株鼻内攻击的保护作用。一个主要的重点将是比较疫苗的效力，仅基于T细胞免疫内部病毒体蛋白与这些反应结合抗体提供外部蛋白。如果成功，第二阶段将审查疫苗和大型动物有效性研究的潜在生产方法。

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.