Molecularly Targeted Vaccines for Anthrax

描述(由申请人提供)： 吸入性炭疽病已成为一种重大的、持续的生物武器和生物恐怖主义威胁。虽然疫苗策略在很大程度上控制了动物种群中的这种疾病，但目前获得许可的人类使用的疫苗有几个缺点，包括严重的不良反应和低免疫原性，导致需要多次免疫。炭疽病的生物学，特别是其毒素的作用，已经在分子和细胞水平上得到了很好的阐明。这提供了一个独特的机会，可以合理地设计和开发一种改进的疫苗，以对抗当前的炭疽病以及未来可能遇到的改良形式。在这个项目中，我们将利用与炭疽毒素相关的大量知识和见解来开发分子靶向疫苗，以防止毒素在感染后的灾难性影响。在仔细分析炭疽毒素所有成分的晶体结构、序列和功能研究的基础上，我们将开发出针对参与毒素激活、组装和黏附的关键蛋白片段的抗体反应的可溶性蛋白疫苗。我们将在体外试验中测试这些疫苗构建体诱导强烈抗体反应的能力以及中和毒素活性的能力。根据对可溶性蛋白构建物的反应分析，选定的构建体将被转移到腺相关病毒疫苗平台，以开发表达疫苗。 传统上，这类疫苗表现出更高的免疫原性，特别是AAV产生了非常持久的反应。将测试以AAV为基础的疫苗的免疫原性和诱导毒素中和抗体的能力，以及与可溶性蛋白免疫原结合使用的能力。最后，最有希望的可溶性蛋白质和表达形式的构建将在兔子的炭疽孢子吸入挑战研究中进行测试。这些实验之前已经针对灵长类动物的实验进行了广泛的验证，而且似乎也与人类炭疽病和保护最密切相关。通过这种方法，我们将开发有希望的候选炭疽疫苗，这些疫苗可以预防当前存在的炭疽菌株，以及基于工程形式的炭疽病毒的新的和增强的威胁。

DESCRIPTION (provided by applicant): Inhalation anthrax has emerged as a significant and continuing biowarfare and bioterrorism threat. Though vaccine strategies have substantially controlled this disease in animal populations, the current vaccine licensed for human use has several shortcomings, including significant adverse reactions and low immunogenicity resulting in the need for multiple immunizations. The biology of anthrax infection and specifically the actions of its toxins have been elegantly elucidated at the molecular and cellular level. This presents a unique opportunity to rationally design and develop an improved vaccine that can counter current anthrax, as well as modified forms that may be encountered in the future. In this project, we will use the substantial body of knowledge and insight available relating to anthrax toxin to develop molecularly targeted vaccines to prevent the catastrophic effects of toxin following infection. Based on careful analysis of the crystal structure, sequence, and functional studies of all components of the anthrax toxins, we will develop soluble protein vaccines that direct antibody responses towards the critical protein segments involved in toxin activation, assembly, and adherence to cells. We will test these vaccine constructs for their ability to elicit strong antibody responses with the ability to neutralize toxin activity in in vitro assays. Based on analysis of responses to the soluble protein constructs, selected constructs will be moved into the adeno-associated virus vaccine platform for development of an expression vaccine. Traditionally such vaccines have exhibited higher immunogenicity, and AAV in particular has yielded very durable responses. The AAV-based vaccines will be tested for immunogenicity and their ability to elicit toxin-neutralizing antibodies, as well as for use in concert with soluble protein immunogens. Finally, the most promising constructs of both soluble protein and expressed forms will be tested in anthrax spore inhalation challenge studies in rabbits. Such experiments have been extensively validated against primate experiments previously and also appear to correlate most closely with human anthrax disease and protection. Through this approach, we will develop promising candidate anthrax vaccines that can protect against currently existing strains of anthrax, as well as new and enhanced threats based on engineered forms of anthrax.