Helicobacter pylori VacA up-regulates secretion of macrophages by activating nuclear factor kB
10.3760/cma.j.issn.0254-5101.2009.05.017
- VernacularTitle:幽门螺杆菌VacA通过激活NF-kB诱导巨噬细胞分泌及凋亡
- Author:
Cunyan LI
;
Yan ZHANG
;
Minjun YU
;
Zhijie LIU
;
Wen YU
- Publication Type:Journal Article
- Keywords:
Helicobacterpylori;
VacA;
Macrophages;
Apoptosis;
NF-kB
- From:
Chinese Journal of Microbiology and Immunology
2009;29(5):454-459
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the effect of VacA on the secretion of THP-1 macrophages as an individual virulence determinant, and the effect of NF-kB on the secretion of THP-1 macrophages. Methods The recombinant plasmid pDsRed-Monomer-Cl/vacA was transfected into macrophages. The cytokine con-tent of TNF-α or IL-1β in the culture medium was tested quantitatively with ELISA kit, respectively. The content of NO or ROS in the culture medium was tested with Griess reagent or DCFH-DA fluorescent probe. The apoptosis rate of macrophages was tested by flow cytometry. The effect of PDTC, an inhibitor of NF-kB, on the secretion and apoptosis of macrophages transfected with the recombinant plasmids, was also studied. The activity of NF-kB was examined in THP-1 cells by electrophoretic mobility gel shift assay(EMSA). Re-suits At 6 h after transfection, the level of TNF-α and IL-1 β in macrophages transfected with the recombi-nant plasmids was significantly higher than that of the control group (P <0.05). At 6 h or 12 h after trans-fection, the level of NO and ROS in macrophages transfected with the recombinant plasmids was significantly higher than that of the control group (P <0.05). At 16 h after transfection, the apoptosis rate of macropha-ges transfected with the recombinant plasmids was significantly higher than that of the control group (P < 0.05). PDTC decreased the production of TNF-α, IL-1 β, NO, ROS and apoptosis rate induced by VacA. VacA was found to trigger NF-kB activation. Conclusion The over-expression of VacA fusion protein can up-regulate secretion and apoptosis of macrophages. Activation of NF-kB is probably involved in the produc-tion of TNF-α, IL-1β, NO, ROS and apoptosis induced by VacA.
