Abstract
The present study was designed to determine the amount of interleukin-8 (IL-8) and secretory leuko-cyte protease inhibitor (SLPI) in cultured human junctional epithelial cells (JE cells) and gingival keratinocytes (GK) stimulated with interleukin-1 alpha (IL-1α) and tumor necrosis factor alpha (TNF-α), which are major inflammatory factors seen in the gingival sulcus or pocket. The JE cells and GK were prepared from 7 subjects with clinical-ly healthy gingiva. The different concentrations of IL-1α (0.1-10ng/ml) and TNF-α (10-1, 000ng/ ml) were added to the serum-free medium (KERATINOCYTEst™-SFM) and cells were cul-tured for four hours. The supernatants were then harvested for further analyses. The amount of IL -8 and SLPI in the supernatants was determined by an enzyme-linked immunosorbent assay (ELISA). From the result of ELISA, both JE cells and GK secreted IL-8 and SLPI by IL-1α a and TNF-α dose -dependently (p<0.05, Mann-whitney's U test). Furthermore, the amount of IL-8 secreted by the JE cells was significantly higher than that by the GK with no stimulant and with stimulation of IL-1α (0.1, 10ng/ml) (p<0.05). And the JE cells secret-ed SLPI higher than GK with stimulation of IL-1α (0.1, 1, 10ng/ml), TNF-α (100ng/ml) (p< 0.05).
These results indicate that the JE cells secrete IL -8 and SLPI in response to these inflammatory factors and the amount of secreted IL-8 and SLPI is higher than GK, suggesting that the junctional epith-elium induces neutrophils to migrate to the gingival sulcus or pocket to protect the periodontal tissue from destruction caused by neutrophil elastase.
