牙龈卟啉单胞菌PG0839基因对KB细胞表达白细胞介素1β和Toll样受体4影响的研究

Effect of PG0839 gene of Porphyromonas gingivalis on inflammatory cytokine in human oral epidermoid carcinoma KB cell

目的 通过牙龈卟啉单胞菌（Porphyromonas gingivalis,Pg）PG0839基因对KB细胞产生炎症因子的影响进行研究,以期为进一步明确毒力岛基因PG0839的功能提供实验依据.方法 运用插入失活方法构建PG0839基因突变菌株.Pg感染KB细胞为实验1组;PG0839基因突变菌株感染KB细胞为实验2组;对照组为单独培养的KB细胞.分别在细菌与KB细胞共同孵育0.5、2、6、12及24 h提取细胞RNA,运用反转录聚合酶链反应（RT-PCR）检测白细胞介素1 β（IL-1β）和Toll样受体4（Toll like recepector-4,TLR-4）mRNA的表达情况.结果 当细菌和KB细胞共同孵育2 h和6 h时,实验2组的IL-1β mRNA表达水平（分别为0.31±0.11、0.57±0.20）显著低于实验1组（分别为0.95±0.48、1.29±0.55）,P＜0.05;在细菌与KB细胞共同孵育0.5 h和6 h时,实验2组的TLR-4mRNA表达水平（分别为0.20±0.09、0.34±0.04）亦显著低于实验1组（分别为0.58±0.09、0.71±0.18）,P＜0.05.结论 PG0839基因在Pg引发的KB细胞炎症过程中发挥作用.

Objective To investigate the effect of PG0839 gene form Porphyromonas gingivalis （Pg） on inflammatory cytokine expression in human oral epidermoid carcinoma KB cell. Methods A mutant in the PG0839 gene of Pg was created by insertional inactivation. Group 1 was chanllenged with PgW83 strain, group 2 with PG0839-defective mutant, and the control group with Dulbecco＇s modified Eagle＇s medium only. KB cells were co-cultured with presence of bacteria for 24 h. At the time point of 0. 5, 2, 6, 12 and 24 h, cells were stored in Trizol. The mRNA expression of interleukin-1β （IL-1β） and Toll like recepector-4 （TLR-4） was examined by reverse transcription polymerase chain reaction. Results At2 h and6 h, IL-1β mRNA expression was lower in group 2 than in group 1（2 h： 0.31 ±0. 11 versus 0.95±0.48, P＜0.05; 6 h： 0.57±0.20 versus 1.29±0.55, P＜0.05）. At 0. 5 h and6 h, TLR-4mRNA expression was lower in group 2 than in group 1 （ 0. 5 h： 0. 20 ± 0. 09 versus 0. 58 ± 0. 09, P ＜ 0. 05;6 h： 0. 34 ± 0. 04 versus 0. 71 ± 0. 18, P ＜ 0.05 ）. Conclusions PG0839 gene may play an important role in Pg-induced inflammatory effects of KB cell.