Novel bioactivities of neutrophil serine proteases against periodontopathic bacteria in innate immunity

本课题的研究成果如下：1。中性粒细胞丝氨酸蛋白酶（弹力酶、组织蛋白酶G和蛋白酶3 (PR3)）通过G蛋白偶联蛋白酶激活受体-2 （PAR-2）激活人非上皮细胞（即人牙龈成纤维细胞（HGF）），诱导细胞产生细胞因子。PR3而不是弹性蛋白酶和组织蛋白酶G激活口腔上皮细胞，这是由于上皮细胞分泌白细胞抑制剂（弹性蛋白酶和组织蛋白酶G的抑制剂，而不是PR3）。发炎的口腔上皮表达PR3。促炎细胞因子诱导PR3以膜结合和酶活性的分泌形式存在。PR3抗体通过PAR-2激活细胞，诱导细胞产生趋化因子。随着T细胞在成人牙周炎患者牙龈组织炎症固有层的积累，研究了牙龈细胞对T细胞因子、白细胞介素-2 （IL-2）和IL-15的免疫反应。在正常和炎症的HGF中，内源性IL-15表达通过核因子-κB激活维持IL-2/15受体β和共同γ的募集。一种胰蛋白酶样蛋白酶，牙龈蛋白酶，来自牙周病细菌，可裂解口腔上皮细胞上表达的细胞间粘附分子-1 (CD54)，从而破坏中性粒细胞与口腔上皮细胞的相互作用。唾液vacd14是先天免疫中的重要分子，可促进牙周病细菌对口腔上皮细胞的侵袭，从而增加趋化因子的产生，在口腔先天免疫中发挥重要作用。

Research results of this project are as follows,1.Neutrophil serine proteases (elastase, cathepsin G, and proteinase 3 (PR3)) activate human non-epithelial cells (i.e.human gingival fibroblasts (HGF)) through G-protein-coupled protease-activated receptor-2 (PAR-2) and induce cytokine production from the cells. PR3 but not elastase and cathepsin G activates oral epithelial cells, due to secretory leukocyte inhibitor (an inhibitor of elastase and cathepsin G but not PR3) from the epithelial cells.2.Inflamed oral epithelium expresses PR3. Proinflammatory cytokines induce PR3 as membrane-bound and secretory forms with enzymatic activity. Antibodies to PR3 activate the cells through PAR-2 and induce chemokine production from the cells.3.As T cells accumulate in the inflamed lamina propria of gingival tissue from patients with adult periodontitis, immune responses of gingival cells to T cell cytokines, interleukin-2 (IL-2) and IL-15 was investigated. Endogenous IL-15 expressed in HGF sustains recruitment of IL-2/15 receptor β and common γ through nuclear factor-κB activation in normal and inflamed HGF.4.A trypsin-like proteases, gingipains, from periodontopathic bacteria cleave intercellular adhesion molecule-1 (CD54) expressed on oral epithelial cells, and consequently disrupt neutrophil-oral epithelial cell interaction.5.SalivaCD14, an important molecule in innate immunity, promotes the invasion of oral epithelial cells by periodontopathic bacteria and consequently augments the production of chemokine, playing an important role in innate immunity in the oral cavity.