A tri-antigen nasal anthrax vaccine against toxins and vegetative bacilli

炭疽芽孢杆菌孢子是一种吸引人的生物武器，可以通过许多不同的方式传播，造成生物恐怖主义，例如在9月11日恐怖袭击后故意污染美国邮件。吸附炭疽疫苗（AVA）是美国唯一的人类炭疽疫苗，被许可用于预防皮肤炭疽，并需要最初的多次注射，随后每年加强。因此，迫切需要开发一种有效且易于施用的疫苗来保护免受炭疽感染，特别是吸入性炭疽，这是炭疽的最致命形式。新的炭疽疫苗的开发一直集中在生产疫苗的基础上纯化的炭疽毒素的保护性抗原（PA）蛋白。然而，研究表明，除了PA之外，炭疽疫苗中还应包括其他抗原，如致死因子（LF）（一种与PA结合形成炭疽致死毒素的蛋白质）和围绕植物炭疽杆菌的聚-γ-D-谷氨酸（PGA）胶囊，以获得更有效的保护。鼻用多抗原炭疽疫苗是有利的，不仅因为它易于给药，而且因为它预期在吸入的炭疽孢子通过其进入宿主的呼吸道的全身隔室和粘膜组织中诱导针对所有抗原的免疫应答.最近的研究数据表明，抗PA粘膜反应在预防动物吸入性炭疽攻击中的重要性。我们建议开发一种有效的鼻炭疽疫苗，可以诱导特异性的全身和粘膜免疫反应，对炭疽毒素和植物芽孢杆菌，将63 kDa形式的PA，一种灭活的LF突变体，和PGA作为抗原到一个脂质为基础的颗粒疫苗载体，我们已经开发。我们假设，这种三抗原鼻疫苗将更有效地预防吸入性炭疽感染比全身注射的疫苗的基础上PA单独。我们的具体目标是确定由该三抗原鼻炭疽疫苗诱导的小鼠免疫应答（目的1），评价由其诱导的抗毒素和抗芽孢杆菌活性（目的2），并验证该疫苗预防小鼠肺炭疽孢子攻击的有效性（目的3）。该项目的完成将为进一步将该疫苗开发成有效且易于施用的人用鼻炭疽疫苗提供良好的科学基础。一个原型的鼻腔给药的多抗原炭疽疫苗的目标，炭疽毒素和杆菌的发展和其在小鼠模型中的有效性的验证将提供一个良好的基础，为新一代的人类炭疽疫苗的发展，这是迫切需要有效的大规模免疫的情况下，隐蔽的炭疽爆发。同样的疫苗或其改良版本也可用于农业行业给牛接种疫苗。

DESCRIPTION (provided by applicant): Bacillus anthracis spores are an appealing biological weapon, which can be distributed through many different means to cause bioterrorism, such as the intentional contamination of the U.S. mail after the September 11 terrorist attacks. Anthrax vaccine adsorbed (AVA), the only human anthrax vaccine in the U.S., was licensed for the prevention of cutaneous anthrax and requires initial multiple injections with subsequent annual boosters. Thus, there is a critical need to develop an efficacious and easily administrable vaccine to protect against anthrax infection, especially the inhalation anthrax, the most lethal form of anthrax. New anthrax vaccine development has been focused on the production of a vaccine based on purified protective antigen (PA) protein of the anthrax toxin. However, it was shown that, besides the PA, other antigens such as the lethal factor (LF), a protein that binds to PA to form anthrax lethal toxin, and the poly-gamma-D-glutamic acid (PGA) capsule surrounding the vegetative anthrax bacilli, should also be included in an anthrax vaccine for more effective protection. A nasal multi- antigen anthrax vaccine will be advantageous not only because it will be ease to administer, but also because it is expected to induce immune responses against all antigens in both the systemic compartment and the mucosal tissues of the respiratory tract, through which inhaled anthrax spores enter hosts. Data from recent studies have indicated the importance of the anti-PA mucosal responses in preventing against inhalational anthrax challenges in animals. We propose to develop an efficacious nasal anthrax vaccine that can induce specific systemic and mucosal immune responses against both the anthrax toxins and the vegetative bacilli by incorporating a 63 kDa form of PA, an inactivated LF mutant, and PGA as antigens into a lipid-based particulate vaccine carrier we have developed. We hypothesize that that this tri-antigen nasal vaccine will be more effective in preventing against an inhalational anthrax infection than the systemic injection of a vaccine based on PA alone. Our specific aims are to define the immune responses induced by this tri-antigen nasal anthrax vaccine in mice (aim 1), to evaluate the anti-toxin and anti-bacillus activities induced by it (aim 2), and to validate the efficacy of this vaccine in preventing against a pulmonary anthrax spore challenge in mice (aim 3). The completion of this project is expected provide a sound scientific foundation for further developing this vaccine into an efficacious and easily administrable nasal anthrax vaccine for humans. The development of a prototype nasally administrable multi-antigen anthrax vaccine that targets both anthrax toxins and bacilli and the validation of its efficacy in a murine model will provide a sound foundation for the development of a new generation human anthrax vaccine, which is urgently needed for effective mass immunization in case of a covert anthrax outbreak. The same vaccine or its modified version can also be used in agricultural industries to vaccinate cattle.