Enhanced cyclooxygenase-2 mRNA expression in human gingival fibroblasts induced by cell contact with human lymphocytes

Prostaglandins, especially prostoglandin E-2 (PGE(2)), play a crucial role in the pathogenesis of periodontal disease. We have previously reported tha t inflammatory mediators interleukin-1 (IL-1) and tumor necrosis factor alp ha (TNF alpha) increase the production of PGE(2) in human gingival fibrobla sts. In this study, we investigated the effect of cell-to-cell interactions between gingival fibroblasts and lymphocytes on PGE(2) production by using co-culture technique. Cell-to-cell contact between gingival fibroblasts an d lymphocytes synergistically enhanced the production of PGE(2) in co-cultu res. In contrast to lymphocytes, the cyclooxygenase-2 (COX-2) mRNA expressi on in gingival fibroblasts was strongly enhanced following cell contact bet ween gingival fibroblasts and lymphocytes. The level of COX-1 mRNA expressi on, however, was not affected either in gingival fibroblasts or in lymphocy tes by the interactions between fibroblasts and lymphocytes. The study demo nstrates that cell contact between gingival fibroblasts and lymphocytes str ongly stimulates PGE2 production partly due to enhanced COX-2 mRNA expressi on in gingival fibroblasts. The cell-to-cell contact between gingival fibro blasts and lymphocytes should be considered as an important regulatory aspe ct For the enhancement of PGE2 in periodontal disease.