Lipid/DNA/Antigen Complexes for Influenza A Viral Vaccination

描述(申请人提供)：甲型流感(流感)感染每年在世界范围内造成相当大的发病率和死亡率，特别是对婴儿、老年人和免疫缺陷者。流感病毒主要在呼吸道复制，毒株也会传播到其他组织，如中枢神经系统。一个日益令人担忧的问题是，最近H5N1等强毒禽流感病毒在亚洲的传播，这可能大大增加人类大流行的风险。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和由重组DNA产生的能力，以及通过接触呼吸道分泌物而迅速传播的能力，FluA也是一种潜在的生物治疗剂。目前的疫苗，如三价灭活疫苗(TIV)或减毒活疫苗(LIV)鼻腔注射，可诱导最低或中等水平的细胞溶解T淋巴细胞(CTL)活性，并主要通过产生依赖于CD4T细胞的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)表面蛋白与目前流行的病毒的紧密匹配。如果中和抗体不能预防呼吸道感染，随后病毒感染的清除主要依靠T细胞，特别是CTL。Juvaris BioTreateutics正在开发并鉴定一种独特的佐剂，这种佐剂特别适用于诱导高水平抗体和T细胞免疫(包括CTL)的疫苗。该佐剂以脂质载体和非编码DNA(CLDC)的复合体为基础，通过多种途径有效，包括肠外、呼吸和口服。将蛋白质抗原包含在CLDC中，可使T细胞对模式抗原(如卵清蛋白或蛾细胞色素c)以及针对呼吸道的病原体(如鼠疫耶尔森氏菌和结核分枝杆菌)产生非常强大的体液和CD4和CDS T细胞反应。某些疫苗接种途径，如腹腔和口服，会导致肺部CTL水平特别显著。这项建议的具体目标是优化针对体内甲型流感特异性T细胞反应的CLDC疫苗系统，特别是在肺部。该优化配方将用于评估对小鼠甲型流感减毒株(HKx31和PR/8/34)以及最近分离的高毒力H5N1禽流感病毒株经鼻腔攻击的保护作用。一个主要的重点将是比较仅基于T细胞对内部病毒蛋白的免疫与这些反应结合外部蛋白抗体所提供的疫苗效力。如果成功，第二阶段将检查疫苗和大型动物功效研究的潜在制造方法。

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.