抄録
CD 26/dipeptidyl peptidase IV (DPPIV) is a cell surface ectoenzyme which participates in immune and inflammatory reactions. We found that CD 26 was only partially expressed on human fibroblasts from periodontal tissues, whereas fibroblasts from lung and skin expressed CD 26 constitutively as revealed by flow cytometry. We examined the possible upregulation of CD 26-expression on human gingival fibroblasts in response to various stimulants. Interleukin (IL) -1 α, tumor necrosis factor (TNF) -α, interferon (IFN) -γ, lipopolysaccharide (LPS) from Porphyromonas gingivalis, Prevotella intermedia, and Escherichia coli and Prevotella glycoprotein augmented CD 26 expression on gingival fibroblasts. Among the stimulants, IL-1 α exhibited the most potent activity. Enzymatic activity of CD 26 was also induced by stimulation on fibroblasts. The upregulation of CD 26 mRNA expression upon stimulation with IL-1 α was also revealed by a quantitative RT-PCR assay. In the kinetic experiment, 48 h and several days were required for maximum CD 26 mRNA accumulation and CD 26 molecule expression on the cell surface, respectively. The addition of cycloheximide almost completely inhibited the accumulation of CD 26 mRNA induced by IL-1 α. These results suggested that induction of CD 26 on human gingival fibroblasts is regulated at the transcriptional level, and is also dependent on a de nove synthesized protein factor (s) .
