INTERLEUKIN 1β-SECRETING CELLS IN INFLAMED GINGIVAL TISSUE OF ADULT PERIODONTITIS PATIENTS

Abstract

Interleukin 1β (IL-1β) is a cytokine with a wide range of biological activities. It is produced by various cell types including macrophages, fibroblasts, and neutrophils. The inflammatory responses mediated by IL-1β play an important role in periodontal tissue destruction. The purposes of this study were: (1) to determine the location of IL-1β in inflamed human gingival tissues by the immunofluorescence method; and (2) to correlate this location to the concomitant presence of macrophage or neutrophils by immunohistochemistry. Five patients with moderate to advanced adult periodontitis receiving periodontal phase I therapy were included in this study. One month after phase I therapy, 15 sites with a probing pocket depth ≥5mm and gingivitis index ≥1 were arranged for modified Widman flap operation. Another three sites with a probing pocket depth ≤3mm and gingivitis index=0 from two gingival healthy subjects who received crown-lengthening operation were also chosen as a control group. After clinical parameter recording, a biopsy of gingival tissues from all sites was obtained during the operation. The gingival specimens were frozen immediately for further immunofluorescent examination of IL-1β and immunocytochemical localization of macrophages and neutrophils. The macrophages were found to be widely distributed in inflamed gingival connective tissue and near-by pocket wall tissue. The neutrophils were aggregated in pocket wall and were sparsely seen in connective tissue. IL-1β immunofluorescent reaction was detected with high intensity in gingival connective tissue especially at the subepithelial region. IL-1β immunofluorescence with low intensity was only occasionally seen in pocket wall tissue. There was a strong association between the presence of macrophages and IL-1β expression. Similarly, there was a positive association between neutrophils and IL-1β immunofluorecence. These results suggested that large amounts of IL-1β are present in inflamed gingival tissues, and that both macrophages and neutrophils are predominate in IL-1β production in inflamed gingival tissues.