TYPE II Enterotoxins as Mucosal Immunomodulators

描述：本申请的目的是评价粘膜 大肠杆菌II型肠毒素LT-IIa和 LT-IIb。在申请人的实验室中的实验证明，LT-IIa 和LT-IIb诱导不同的和独特的增强免疫模式， 反应，并且这些模式与诱导的模式截然不同 霍乱毒素（CT）例如，尽管CT用作佐剂诱导 主要是基于抗体同种型和细胞因子的辅助性T细胞2型应答 II型肠毒素，特别是LT-IIb，诱导T辅助细胞1和 辅助T细胞2型反应。这些数据提供了强有力的证据，LT-IIa，LT-IIb， 和CT利用不同的细胞和分子诱导其佐剂活性 机制等因此，II型毒素提供了一套优雅的工具， 研究粘膜佐剂诱导的机制。虽然与 结构、LT-IIa、LT-IIb和CT结合到不同组细胞表面 受体。据推测，这种独特的佐剂活性， 毒素受其受体结合特异性控制。为了验证这一 假设，II型毒素的佐剂活性将在 使用口腔病原体变形链球菌的AgI/II作为粘膜小鼠模型， 模型抗原将评估抗体和细胞应答。这些 研究将通过收集受体结合突变体，杂交 分子和嵌合毒素。 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 将使用共聚焦显微镜来鉴定细胞中的免疫活性细胞。 鼻淋巴组织和引流淋巴结，最初与 鼻内接种后的毒素。作为进一步的手段， 毒素/细胞相互作用的佐剂诱导，取免疫活性细胞 将鼻淋巴组织中的毒素特异性 使用流式细胞术分析表面受体。最后， 作为佐剂/抗原递送载体的无毒嵌合II型蛋白将 被评价。在这些研究结束时，实验室将很好地 定位于评估II型毒素的治疗潜力， 在随后的新疫苗生产中使用粘膜佐剂， 防止感染口腔、胃和泌尿生殖道粘膜的病原体。

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.