中文摘要：

目的比较不同fimA基因型牙龈卟啉单胞菌（P.gingivalis）刺激下口腔上皮细胞白细胞介素-8（IL-8）的表达水平,初步探讨P.gingivalis致病性与其fimA基因型的关系。方法P.gingivalis ATCC 33277（Ⅰ型fimA）、W83、47A-1（Ⅳ型fimA）和KB细胞ATCC CCL-17共同孵育24h,以未受刺激的KB细胞作为对照组,分别在1、3、6、24h收集细胞和培养上清液。RT-PCR检测KB细胞IL-8m RNA的动态表达,酶联免疫反应检测培养上清液中IL-8的动态变化。结果2种fimA基因型菌株刺激1h,KB细胞IL-8mRNA的表达上调至峰值,高于对照组,3～24hIL-8m RNA的表达水平接近对照组;P.gingivalis感染细胞后3～24h,上清液中的IL-8水平低于对照组,Ⅳ型菌株低于Ⅰ型菌株;IL-8mRNA及其蛋白表达不完全一致,提示IL-8的表达存在转录后水平的调节。结论fimA基因型与口腔上皮细胞IL-8的表达水平相关,提示P.gingivalis致病性与其fimA基因型相关。

英文摘要：

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 determined 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.