TYPE II Enterotoxins as Mucosal Immunomodulators

作为粘膜免疫调节剂的 II 型肠毒素

• 批准号: 6587277
• 负责人: Terry D. Connell
• 金额: $ 0.4万
• 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/6587277
• 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-IIB。申请人实验室的实验证明了LT-IIA LT-IIB诱导增强免疫的不同和独特的模式 回答，这些模式与所诱发的模式有很大不同 由霍乱毒素（CT）。例如，虽然CT用作佐剂诱导 主要是基于抗体同种型和细胞因子的T辅助2型反应 图案，II型肠毒素，尤其是LT-IIB，诱导T助手1和 T辅助2响应。这些数据提供了有力的证据，表明LT-IIA LT-IIB， CT使用不同的细胞和分子诱导其辅助活性 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。尽管相关 结构，LT-IIA，LT-IIB和CT与不同的细胞表面结合 受体。假设 毒素由其受体结合特异性支配。测试这个 假设，将在A中分析II型毒素的辅助活性 使用口腔病原体链球菌突变的AGI/II作为A的粘膜小鼠模型 模型抗原。将评估抗体和细胞反应。这些 研究将通过收集的受体结合突变体，杂种来促进研究 该实验室可用的分子和嵌合毒素。 免疫研究将与对免疫组织学的研究结合 淋巴组织开始研究毒素诱导的细胞成分 辅助活动。 共聚焦显微镜将用于鉴定在 鼻淋巴组织和最初与 鼻内接种后的毒素。作为相关的进一步手段 与毒素/细胞相互作用的辅助诱导，免疫能力细胞 鼻淋巴组织将分类以表达毒素特异性 使用流式细胞仪分析表面受体。最后，潜力 无毒嵌合II型蛋白作为辅助/抗原递送车将 进行评估。这些研究结束时，实验室将很好 定位以评估II型毒素的治疗潜力 随后生产新疫苗的粘膜佐剂将 预防感染口服，胃和泌尿生殖的病原体。