MECHANISM OF CHOLERA TOXIN AND E COLI LT ADJUVANTICITY

世界卫生组织1995年传染病死亡报告显示， 在那一年里，全球有1300多万人死亡。大多数人 其中死亡是由首次接触和感染的微生物引起的 然后定植或穿过粘膜表面感染宿主。一个 已经开发了许多策略来促进粘膜 预防这些疾病的免疫接种，包括添加细菌 具有已知佐剂特性的产品。这两种细菌产品含有 最有潜力发挥粘膜佐剂作用的是霍乱毒素 (T)，由各种霍乱弧菌菌株产生，以及不耐热的 几株产肠毒素大肠杆菌产生的肠毒素(LT) Coli. CT和LT的一些突变体已经被开发出来，试图 将这些分子理想的佐剂特性与它们的 有毒的影响。活性中心和蛋白水解酶中心的突变体 在各种动物模型中构建和评估不同的 抗原。关于CT和CT辅助性的几个重要问题 这些毒素的突变体仍有待回答。其中一些问题是 实用性和答案将影响立即和短期使用 人类疫苗中的这些分子。其他问题解决了根本的问题 与辅助性相关的机制和答案将有他们的 对未来佐剂和疫苗策略的设计产生最大影响 并在发展中更好地了解疫苗诱导 豁免权。该提案包括一系列具体目标，旨在 直接解决这些问题。最重要的方面之一就是 建议的研究是CT、LT、活动部位的并列比较 突变体、酶切位点突变体和重组B亚基 诱导特定的、有针对性的免疫结果作为途径的函数 免疫和联合注射抗原的性质。与 在拟议研究中获得的信息，未来的疫苗战略 可使用最佳佐剂/抗原配方设计 多种细菌和病毒病原体的给药途径。 这一建议还检查了潜在的细胞和细胞内 这些不同分子激活的信号通路可以更好地 在细胞水平上理解佐剂的机制。

The WHO report of Infectious Disease deaths for 1995 indicated that there were more than 13 million deaths world-wide during that year. The majority of those deaths were caused by organisms that first make contact with and then either colonize or cross mucosal surfaces to infect the host. A number of strategies have been developed to facilitate mucosal immunization to prevent these diseases, including addition of bacterial products with known adjuvant properties. The two bacterial products with the greatest potential to function as mucosal adjuvants are cholera toxin (T), produced by various strains of Vibrio cholerae, and the heat-labile enterotoxin (LT) produced by some enterotoxigenic strains of Escherichia coli. A number of mutants of CT and LT have been developed in an attempt to dissociate the desirable adjuvant properties of these molecules from their toxic effects. Both active-site and protease-site mutants have been constructed and evaluated in a variety of animal models with different antigens. Important questions regarding the adjuvanticity of CT and CT and mutants of these toxins remain to be answered. Some of these questions are practical and the answers will impact the immediate and short term use of these molecules in human vaccines. Other questions address the underlying mechanisms associated with adjuvanticity and the answers will have their greatest impact in the design of future adjuvants and vaccine strategies and in the development of a better understanding of vaccine induced immunity. The proposal includes a series of Specific Aims designed to directly address these issues. One of the most important aspects of the proposed study is a side-by-side comparison of CT, LT, active-site mutants, protease-site mutants, and recombinant B-subunits for the ability to induce specific, targeted immunologic outcomes as a function of route of immunization and nature of the co-administered antigen. With the information obtained in the proposed studies, future vaccine strategies can be designed employing the optimum adjuvant/antigen formulation and route of administration for a variety of bacterial and viral pathogens. This proposal also examines the underlying cellular and intracellular signaling pathways activated by these different molecules to better understand the mechanisms of adjuvanticity at the cellular level.