Adjuvant Enhanced Antiviral Immunity

描述（由申请人提供）：甲型流感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。目前的疫苗，如静脉注射的三价灭活疫苗（TIV），要么不加佐剂，要么加了氢氧化铝（明矾）佐剂。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。如果中和抗体不能预防呼吸道感染，后续病毒感染的清除主要依赖于T细胞，特别是CD8+ T细胞亚群中的溶细胞T淋巴细胞（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。佐剂是基于阳离子脂质载体和非编码DNA复合物（CLDC）。蛋白抗原与CLDC的包涵导致极其强大的体液和CD4+和CD8+ t细胞反应。CLDC佐剂的独特之处在于，它既是一种通过脂质体将相关抗原靶向到抗原提呈细胞的递送系统，又是一种通过质粒DNA的免疫刺激佐剂。该提案的最终成果是完成CLDC产品的临床前评估和开发，用于病毒疫苗，特别是流感疫苗的佐剂。CLDC流感佐剂的产品开发战略侧重于利用近期的机会，为目前已批准的疫苗（在美国和国外）提供佐剂，同时认识到目前正在评估的重组疫苗方法的潜力。本提案的具体目标是：1)确定佐剂和疫苗制备和储存的限制；2)剂量优化；3)使用现有佐剂或不使用佐剂接种CLDC/Ag疫苗后免疫反应的强度和持久性的比较；4)确定佐剂在小鼠和非人灵长类动物中诱导适应性免疫的作用机制；5) CLDC佐剂单价分裂疫苗（将自行制备）或单价全灭活疫苗病毒的异亚型保护程度。有重要证据表明，异亚型免疫可能在自然感染之后产生，在较小程度上，也可能在目前的疫苗接种策略之后产生。使用CLDC佐剂疫苗可能会显著增强这种免疫力，但需要在小鼠和非人类灵长类动物中正式证明这一点，然后才能对援引这种机制的疫苗策略进行临床试验并广泛应用。

DESCRIPTION (provided by applicant): Influenza A infection causes annual substantial morbidity and mortality worldwide, particularly for infants, the elderly, and the immuncompromised. Current vaccines, such as the parenterally administered trivalent inactivated vaccine (TIV) are administered either unadjuvanted or adjuvanted with aluminum hydroxide (alum). 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 cytolytic T lymphocytes (CTL) of the CD8+ T-cell subset. 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 cationic lipid carrier and non-coding DNA complex (CLDC). Inclusion of protein antigens with CLDC results in an extremely robust humoral and CD4+ and CD8+ T-cell response. The unique aspect of the CLDC adjuvant is that it functions both as a delivery system that targets associated antigens to antigen presenting cells via the liposome component and an immunostimulatory adjuvant via the plasmid DNA. The final product resulting from this proposal is the completion of pre-clinical evaluation and development of the CLDC product for use as an adjuvant in viral vaccines and specifically for influenza. The product development strategy for the CLDC adjuvant in influenza is focused on the exploitation of the near-term opportunity of adjuvanting currently approved vaccines (in the U.S. and abroad) while recognizing the potential of recombinant vaccine approaches currently being evaluated. The specific goals of this proposal are to: 1) Establish limits on adjuvant and vaccine preparation and storage; 2) Optimization of dose; 3) Comparison of the magnitude and durability of the immune response following CLDC/Ag vaccination with existing adjuvants or no adjuvants; 4) Determine mechanism of action of the adjuvant in inducing adaptive immunity in mouse and non-human primate; 5) extent of heterosubtypic protection with CLDC adjuvanted monovalent split vaccines, which will be prepared in house, or monovalent whole inactivated vaccine virus. There is significant evidence that heterosubtypic immunity may follow natural infection and, to a lesser extent, current vaccination strategies. Such immunity will likely be markedly enhanced using CLDC adjuvanted vaccines, but a formal demonstration of this in mice and non-human primates is required before vaccine strategies invoking this mechanism can be clinically tested and adopted for general application.