Immunohistological determination of interleukin-1 beta in inflamed human gingival epithelium

Interleukin-1 beta (Il-1 beta) is the predominant form of Il-1 produced by monocytes of the blood and by macrophages of various tissues. Human keratinocytes express both Il-1 alpha and Il-1 beta mRNA, but appear to produce mainly Il-1 alpha. The aim of this study was to determine the localization of interleukin-1 beta and interleukin-1 beta receptors in human gingival epithelium by different immunohistochemical methods. The alkaline phosphatase and the immunogold staining technique, as well as fluorescence microscopy, were used to investigate active participation of gingival epithelial cells in the development of periodontitis. Biopsies of human interdental papillae showed some activity of epithelial cells in the production of Il-1 beta. Single cells, clusters or larger areas of the sulcular and oral epithelium appeared to produce Il-1 beta at inflamed sites, and in these areas the normal epithelial structure was disturbed. Epithelial cells grown from the same biopsies appear able to express specific receptor molecules for Il-1 beta under normal culture conditions. It is concluded that gingival keratinocytes might be activated by inflammatory irritants and participate actively in the inflammatory processes.