MECHANISM OF CHOLERA TOXIN AND E COLI LT ADJUVANTICITY

卫生组织1995年传染病死亡报告指出， 那一年全世界有一千三百多万人死亡大多数 这些死亡的原因是生物体首先接触， 然后定殖或穿过粘膜表面感染宿主。一 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。这两种细菌产物 最有潜力作为粘膜佐剂的是霍乱毒素 (T)，由各种霍乱弧菌菌株产生， 某些产肠毒素大肠杆菌菌株产生的肠毒素 杆菌 已经开发了许多CT和LT的突变体，试图 使这些分子的所需佐剂性质与它们的 毒性作用。活性位点突变体和蛋白酶位点突变体都已被 在各种动物模型中构建和评估， 抗原关于CT和CT辅助作用的重要问题， 这些毒素的突变体仍有待解答。其中一些问题是 实用，答案将影响即时和短期使用 这些分子在人类疫苗中。其他问题涉及到 与佐剂相关的机制，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 在开发疫苗诱导的更好的理解 免疫力该提案包括一系列具体目标， 直接解决这些问题。其中最重要的一个方面， 拟议的研究是对CT、LT、活性部位 突变体、蛋白酶位点突变体和重组B亚基， 作为途径的函数， 免疫和共同施用抗原的性质。与 在拟议研究中获得的信息，未来的疫苗策略 可以采用最佳佐剂/抗原制剂进行设计， 用于多种细菌和病毒病原体的给药途径。 该建议还检查了潜在的细胞和细胞内 这些不同的分子激活信号通路， 理解细胞水平上的佐剂作用机制。

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.