RESUMEN
Objective To investigate the effect of VvhA recombinant protein to the expression of IL-8 in human intestinal epithelial Caco-2 cells. Methods The VvhA recombinant protein(rVvhA) was ex-pressed by prokaryotic expression vector pET-28a (+)-whA in E. coli BL21 (DE3) , purified by Ni~(2+)-NTA affinity chromatography refoldod by stepwise deliquation together with dialysis methods and identified by Western blot. The cytotoxic of rVvhA to human Caco-2 cells was measured by CCK-8. The transcription of IL-8 mRNA in human Caco-2 cells induced by rVvhA was determined by RT-PCR, and the expression of IL-8 in human Caco-2 cells induced by rVvhA was determined by ELISA assay. Results rVvhA was purified with high purity up to 95%. The viability of human Caco-2 cells treated with 1.5 HU/ml rVvhA was inhibi-ted significantly (P < 0.05). The rVvhA can induce human Caco-2 cells to increase the transcription and expression of IL-8 in dose- and time-dependent manner. The transcription of IL-8 gene in human Caco-2 cells treated with 0.6 HU/ml rVvhA in 30 min can be up-regulated significantly, and the expression of IL-8 in human Caco-2 cells treated with rVvhA in 4 h can be increased significantly. Conclusion rVvhA has cy-totoxic to human Caco-2 and can increase the expression of IL-8, it might play a major role in the inflamma-tory reaction of rVvhA-exposed cells.