Discharge of collagenase from a gingival fibroblast infected with oral mycoplasma

人正常牙龈成纤维细胞（Gin-1）经平板培养，暴露于唾液支原体（Ms）或口腔支原体（Mo）的活细胞或超声破裂的Ms或牙龈卟啉单胞菌（Pg）的细胞膜后，随时间的推移，细胞形态呈球状。Mo膜和Ms膜的活细胞诱导这种形态变化最强烈。暴露96 h后，后者进一步导致Gin-1细胞脱离平板。形态学的改变和脱落被认为是由细胞排出的胶原酶引起的，但在培养基中没有发现胶原酶活性。另一种可能性是，形态变化和脱离是由于细胞因子的产生，因此，使用酶联免疫试剂检测培养基中炎症细胞因子（il -1 β， IL-6和TNFalpha）的产生。所有病例均检测到高含量的IL-6。Pg刺激也检测到TNFalpha和il -1 β，但Ms和Mo刺激未检测到。IL-6最初被认为是一种刺激B细胞产生免疫球蛋白的因子，并被认为与关节炎等炎症有关。在口腔科学领域，IL-6在牙周病的病变中被发现，并被讨论参与其病因。因此，目前口腔支原体诱导牙龈成纤维细胞分泌IL-6的发现表明它们在牙周病中起重要的病因学作用。

Human normal gingival fibroblast (Gin-1) cells cultured in a plate showed a morphological change to spheroid with time when they were exposed to either vialbe cells of Mycoplasma salivarium (Ms) or Mycoplasma orale (Mo) or cell membranes of Ms or Porphyromonas gingivalis (Pg) cells fractured by sonication. This morphological change was most strongly induced by viable cells of Mo and Ms membranes. The latter further caused, after 96 h-exposure, detachment of Gin-1 cells from the plate.The morphological change and the detachment were supposed to be caused by collagenase discharged from the cells, but no collagenase activity was found in the culture medium. There is another possibility that the morphological change and the detachment are attributed to cytokines produced and, hence, the production of inflammatory cytokines (IL-1beta, IL-6 and TNFalpha) in the culture medium was investigated by using an enzyme-linked immunosorvent assay. High contents of IL-6 were detected for all cases. TNFalpha and IL-1beta were also detected for Pg stimulation but not for Ms and Mo stimulations.IL-6 was originally identified as a factor which stimulates immunoglobulin production by B cells and is discussed to be involved in inflammation such as arthritis. In the field of dental science, IL-6 was found in the lesion of periodontal disease and is discussed to be involved in its etiology. Therefore, the present finding that oral mycoplasmas induce IL-6 secretion from a gingival fibroblast suggests that they play an important etiological role in periodontal diesease.