[Interleukin-8 regulations of oral epithelial cells by porphyromonas gingivalis with different fimA genotypes].

Objective: The expression of heterogenic virulence properties depends on its clonal diversity. The aim of the study was to investigate the mechanism of interleukin-8 (IL-8) regulations of oral epithelial cells by challenge of Porphyromonas gingivalis (P. gingivalis) with different fimA genotypes, discuss the relation between fimA genotype and its pathogenicity.

Methods: P. gingivalis ATCC 33277 (type I), W83 (type IV), 47A-1 (type IV) were assessed for their inductions of IL-8 expression in human oral epithelial cells (KB cell line, ATCC CCL-17). KB cells without stimulation of P. gingivalis were used as control group. IL-8 mRNA expression was de termined by reverse transcription polymerase chain reaction (RT-PCR) at different time intervals (1, 3, 6, 24 h) following continuous co culture of bacteria with KB cell line, and IL-8 protein levels in culture supernatant was determined by enzyme-linked immunosorbent assay.

Results: IL-8 mRNA levels were up-regulated and reached its high peak at 1 h following both genotypes infection, then decreased to base level till 24 h. Attenuation of IL-8 protein levels was down-regulated when KB cell co-cultured with both genotypes for 3 h till 24 h, and type IV was lower than type I. IL-8 and IL-6 mRNA expression were not consistent with their protein levels, which indicated post-transcriptional regulations.

Conclusion: fimA genotypes of P. gingivalis are related with the effect of IL-8 inductions, which indicates fimA genotype is associated with pathogenesis of P. gingivalis.