REGULATION OF CELLULAR INFLAMMATORY RESPONSES

细胞炎症反应的调节

• 批准号: 6104727
• 负责人: MICHAEL W RUSSELL
• 金额: $ 6.55万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6104727
• 关键词: antibody receptor; bacterial antigens; bactericidal immunity; cytotoxicity; eosinophil; fibroblasts; flow cytometry; gingiva; human tissue; immune complex; immunofluorescence technique; immunoglobulin A; immunoglobulin G; immunopathology; inflammation; interleukin 1; interleukin 6; leukocyte activation /transformation; messenger RNA; monocyte; neutrophil; northern blottings; periodontium disorder; phagocytosis; polymerase chain reaction; radioimmunoassay; receptor expression; tissue /cell culture; transforming growth factors; tumor necrosis factor alpha

Among the infiltrating leukocytes present in inflamed human gingiva, monocytes/macrophages, neutrophils, and eosinophils express surface receptors for the Fc part of immunoglobulin (Ig) A (FcalphaR) and of IgG (FcgammaR). However, the physiological and pathological significance of the signals transduced by FcalphaR are incompletely understood, especially in comparison with FcgammaR-mediated inflammatory processes. IgA, including IgA antibodies to periodontal pathogens, is produced by plasma cells in inflamed gingiva, and possesses anti-inflammatory properties with respect to inhibition of complement activation. Conversely, stimulation of eosinophils with IgA induces degranulation which may lead to tissue damage. This component of the Research Center for Oral Biology, in collaboration with other Center Projects and Cores, proposes to examine the hypothesis that human IgA antibodies modulate inflammatory processes mediated by infiltrating leukocytes relevant to human periodontal disease. The presence and regulation of FaclphaR on leukocytes in inflamed gingival tissue will be examined by immunofluorescence and flow cytometry. As gingival leukocytes are derived from the circulating pool, the up-regulation of FcalphaR on peripheral blood monocytes, neutrophils, and eosinophils, and model promonocytic and promyelocytic cell lines by exposure to various molecular forms, subclasses, immune complexes, and fragments (generated by bacterial IgA proteases) of human IgA, and by relevant cytokines (IL- 1, IL-6, and TNF-alpha for monocytes and neutrophils; IL-3, IL-5, and GM- CSF for eosinophils) will be investigated in vitro. The techniques will include flow cytometry for FcalphaR surface expression and analysis of FcalphaR-mRNA transcription. the consequences of stimulating these cells through he FcalphaR, in comparison with receptors for IgG and/or complement, will be examined with respect to: (i) the generation of inflammatory cytokines (IL-1, IL-6, and TNF-alpha) by monocytes and neutrophils, and of TGF-alpha by eosinophils; (ii) the release of proteases by monocytes and neutrophils; and (iii) the release of cytotoxic granule proteins by eosinophils. The potential for inflammatory gingival tissue damage caused by factors released from IgA- stimulated leukocytes will be assessed by determining: (i) the presence of released eosinophil granule proteins in inflamed gingival tissue; (ii) cytotoxicity of IgA-stimulated leukocytes and their products towards oral mucosal fibroblasts; and (iii) the development of tissue-destructive properties (induction of matrix metalloproteinases) in cultured oral mucosal fibroblasts exposed to IgA-stimulated eosinophils and their products. The fundamental question that these studies seek to address is whether IgA acts antagonistically to or synergistically with IgG in inflammatory lesions. The answer will not only help to elucidate the immunopathogenesis of human periodontal disease, but also advance knowledge of the physiology of human IgA and its role in modulating inflammatory processes.

在发炎的人类牙龈中存在的浸润白细胞中， 单核细胞/巨噬细胞、中性粒细胞和嗜酸性粒细胞表达表面 免疫球蛋白 (Ig) A (FcalphaR) 和 IgG Fc 部分的受体 （FcγR）。 然而，其生理和病理意义 FcalphaR 转导的信号尚不完全清楚， 尤其是与 FcgammaR 介导的炎症过程相比。 IgA，包括针对牙周病原体的 IgA 抗体，由以下物质产生： 发炎牙龈中的浆细胞，具有抗炎作用 与抑制补体激活有关的特性。 相反，IgA 刺激嗜酸性粒细胞会诱导脱颗粒 这可能会导致组织损伤。 研究中心的这个组成部分 对于口腔生物学，与其他中心项目和核心合作， 提议检验人类 IgA 抗体调节的假设 与相关的浸润白细胞介导的炎症过程 人类牙周病。 FaclphaR 的存在和调节 发炎牙龈组织中的白细胞将通过以下方式进行检查： 免疫荧光和流式细胞术。 由于牙龈白细胞 源自循环池，FcalphaR 的上调 外周血单核细胞、中性粒细胞、嗜酸性粒细胞及模型 早单核细胞和早幼粒细胞系通过暴露于各种 分子形式、亚类、免疫复合物和片段（生成 人类 IgA 的细菌 IgA 蛋白酶）以及相关细胞因子（IL- 1、单核细胞和中性粒细胞的IL-6和TNF-α； IL-3、IL-5 和 GM- 脑脊液（嗜酸性粒细胞）将在体外进行研究。 这些技术将 包括用于 FcalphaR 表面表达和分析的流式细胞术 FcalphaR-mRNA 转录。 刺激这些细胞的后果 通过 FcalphaR，与 IgG 受体和/或 补充，将在以下方面进行审查：（i） 单核细胞和炎症细胞因子（IL-1、IL-6 和 TNF-α） 嗜中性粒细胞和嗜酸性粒细胞的 TGF-α； (二) 释放 单核细胞和中性粒细胞的蛋白酶； (iii) 释放 嗜酸性粒细胞的细胞毒性颗粒蛋白。 的潜力 IgA-释放因子引起的炎症性牙龈组织损伤 将通过以下方式评估受刺激的白细胞： (i) 是否存在 发炎牙龈组织中释放的嗜酸性粒细胞颗粒蛋白； (二) IgA刺激的白细胞及其产物对口腔的细胞毒性 粘膜成纤维细胞； (iii) 组织破坏性的发展 培养口腔中的特性（基质金属蛋白酶的诱导） 暴露于 IgA 刺激的嗜酸性粒细胞的粘膜成纤维细胞及其 产品。 这些研究试图解决的基本问题 IgA 与 IgG 的作用是拮抗还是协同作用 炎症性病变。 答案不仅有助于阐明问题 人类牙周病的免疫发病机制，也推进 了解人类 IgA 的生理学及其在调节中的作用 炎症过程。