TYPE II Enterotoxins as Mucosal Immunomodulators

作为粘膜免疫调节剂的 II 型肠毒素

• 批准号: 6551476
• 负责人: Terry D. Connell
• 金额: $ 1.2万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-15 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6551476
• 关键词: Escherichia coli; SDS polyacrylamide gel electrophoresis; Streptococcus mutans; bacterial antigens; cell migration; cellular immunity; chemical structure function; chimeric proteins; cholera toxin; confocal scanning microscopy; enterotoxins; enzyme linked immunosorbent assay; flow cytometry; green fluorescent proteins; helper T lymphocyte; immunization; immunocytochemistry; immunomodulators; laboratory mouse; lymph nodes; mucosal immunity; mutant; protein transport; tissue /cell culture; western blottings

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.

描述：本应用的目的是评估粘膜 大肠杆菌 II 型肠毒素、LT-IIa 和 LT-IIa 的佐剂活性 LT-IIb。申请人实验室的实验表明，LT-IIa 和 LT-IIb 诱导不同且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，虽然 CT 用作佐剂会诱导 主要是基于抗体同种型和细胞因子的 T 辅助细胞 2 型反应 模式，II 型肠毒素，特别是 LT-IIb，诱导 T 辅助细胞 1 和 T 助手 2 响应。这些数据提供了强有力的证据表明 LT-IIa、LT-IIb、 CT 和 CT 使用不同的细胞和分子诱导其佐剂活性 机制。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。虽然相关于 结构，LT-IIa、LT-IIb 和 CT 结合不同组的细胞表面 受体。据推测，独特的辅助活性 毒素受其受体结合特异性的控制。为了测试这个 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。将评估抗体和细胞反应。这些 一系列受体结合突变体、杂交体将促进研究 本实验室提供的分子和嵌合毒素。 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 辅助活性。 共聚焦显微镜将用于识别细胞中的免疫活性细胞 鼻淋巴组织和最初相互作用的引流淋巴结 鼻内接种后产生的毒素。作为关联的进一步手段 毒素/细胞相互作用的佐剂诱导，取出免疫活性细胞 来自鼻淋巴组织的毒素特异性表达将被分类 使用流式细胞术分析表面受体。最后，潜力 无毒嵌合 II 型蛋白作为佐剂/抗原递送载体 进行评估。在这些研究结束时，实验室将表现良好 旨在评估 II 型毒素的治疗潜力 粘膜佐剂在随后生产的新疫苗中将 防止病原体感染口腔、胃和泌尿生殖粘膜。