TYPE II Enterotoxins as Mucosal Immunomodulators

描述：此应用程序的目标是评估粘膜 大肠杆菌II型肠毒素LT-IIa和LT-IIa的佐剂活性 它-IIb。申请人实验室的实验证明LT-IIa 和LT-IIb诱导不同和独特的免疫增强模式 反应，而且这些模式与诱导的模式有很大的不同 霍乱毒素(CT)。例如，尽管CT用作佐剂诱导 主要是基于抗体同型和细胞因子的T辅助细胞2型反应 模式，II型肠毒素，特别是LT-IIb，诱导T辅助分子1和 T帮助者2响应。这些数据为LT-IIa、LT-IIb、 和CT通过不同的细胞和分子诱导其佐剂活性 机械装置。因此，II型毒素提供了一套优雅的工具来 探讨黏膜佐剂诱导的机制。尽管在中相关 结构、LT-IIa、LT-IIb和CT结合到不同的细胞表面 感受器。据推测，其独特的佐剂活性 毒素受其受体结合的特异性所支配。为了测试这一点 假设，第二类毒素的佐剂活性将在一个 口腔病原菌变形链球菌AgI/II作为小鼠粘膜模型的研究 模型抗原。抗体和细胞反应都将被评估。这些 研究将由一系列受体结合突变体、杂交种来促进 分子，和嵌合毒素，在这个实验室是可用的。 免疫研究将与免疫组织学研究相结合 淋巴组织开始研究毒素诱导的细胞成分 佐剂活性。 共聚焦显微镜将被用来识别免疫活性细胞在 鼻部淋巴组织和最初与之相互作用的引流淋巴结 鼻腔接种后的毒素。作为进一步关联的手段 用毒素/细胞相互作用诱导佐剂，取免疫活性细胞 将鼻腔淋巴组织进行分类，进行毒素特异性表达 用流式细胞术分析细胞表面受体。最后，潜在的 作为佐剂/抗原递送载体的无毒嵌合II型蛋白将 被评估。在这些研究结束后，实验室将会很好 定位于评估II型毒素的治疗潜力为 在随后生产的新疫苗中使用粘膜佐剂将 防止感染口腔、胃和泌尿生殖系统粘膜的病原体。

DESCRIPTION: The objective of this application is to evaluate the mucosal adjuvant activities of the Escherichia coli Type II enterotoxins, LT-IIa and LT-IIb. Experiments in the laboratory of the applicant demonstrated that LT-IIa and LT-IIb induce different and distinctive patterns of enhanced immune responses, and that those patterns are profoundly different from those induced by cholera toxin (CT). For example, whereas CT used as an adjuvant induces predominantly a T helper 2-type response based on antibody isotype and cytokine patterns, Type II enterotoxins, particularly LT-IIb, induce both T helper 1 and T helper 2 responses. These data provide strong evidence that LT-IIa, LT-IIb, and CT induce their adjuvant activities using different cellular and molecular mechanisms. As such, the Type II toxins provide an elegant set of tools for investigating the mechanisms of mucosal adjuvant induction. Although related in structure, LT-IIa, LT-IIb and CT bind to different sets of cell surface receptors. It is hypothesized that the distinctive adjuvant activities of the toxins are governed by their receptor-binding specificities. To test this hypothesis, the adjuvant activities of the Type II toxins will be analyzed in a mucosal mouse model using AgI/II of the oral pathogen Streptococcus mutans as a model antigen. Both antibody and cellular responses will be assessed. These studies will be facilitated by a collection of receptor-binding mutants, hybrid molecules, and chimeric toxins that are available in this laboratory. Immunization studies will be combined with immunohistological investigations of lymphoid tissue to begin to investigate the cellular component of toxin-induced adjuvant activity. Confocal microscopy will be used to identify the immunocompetent cells in the nasal lymphoid tissue and the draining lymph nodes that initially interact with the toxins after intranasal inoculation. As a further means to correlate adjuvant induction with toxin/cell interactions, immunocompetent cells taken from nasal lymphoid tissue will be classified for expression of toxin-specific surface receptors using flow cytometry analysis. Finally, the potential of non-toxic chimeric Type II proteins as adjuvant/antigen delivery vehicles will be evaluated. At the conclusion of these studies, the laboratory will be well positioned to evaluate the therapeutic potential of the Type II toxins as mucosal adjuvants in the subsequent production of new vaccines that will protect against pathogens that infect the oral, gastric and urogenital mucosae.