Panton-valentine leukocidin induce THP-1 macrophages IL-8 and IL-6 response through nuclearTLR4/NF-KB pathway
Objective To investigate the influence of panton-valentine leucocidin （PVL） on ex- pression of Toll like receptor 4 （TLR4）/nuclear factor-kappa B （ NF-KB ） signals and IL-8, IL-6 in THP-1 macrophages, and to study the mechanism of PVL-related lung tissue damage. Methods THP-1 cells were cuhured in the presence of 100 nmol/L phorbol-12-myristate 3-acetate （PMA） for 48 h to induce monocytemacrophage differentiation, rPVL-F and rPVL-S were induced and expressed from the recombinant plasmid, respectively purified with chromatographic column. After that, THP-1 macrophages were incubated with rPVL, and then ELISA was performed to test expression of IL-8 and L-6 in supernatants fluid ; RT-PCR was performed to detect expression of IL-8, L-6 and TLR4 ; NF-KB was analyzed by Western blot and immunohistochemistry method. Results PVL was able to induce expression of IL-8 and IL-6 in THP-1 macrophages in time-and concentration-dependent manners. PVL could also significantly promote the activation of TLR4/NF- KB signals. Conclusion PVL can activate the expression of TLR4/NF-KB signals, and increased the high expression of inflammatory cytokines. Maybe it＇s the mechanism of action of PVL exerts the function of lung tissue damage. 
 
Key words: 
Panton-valentine leucocidin;  THP-1 macrophages;  Nuclear factor-kappa B;  IL-8; IL-6