Abstract: Objective To study whether lipopolysaccharide (LPS) can influence cytokine expression of macrophage infected by M.bovis BCG.Methods ELISA method was used to measure the cytokine expression of the different groups including macrophage group, macrophage +BCG+LPS group,macrophage +BCG group, macrophage +LPS group, and thus to compare the differences.Results Little IL-12 and TNF-α was produced in single macrophage group,LPS can stimulate macrophage group especially macrophage group infected by M.bovis BCG to produce significant amount of IL-12 and TNF-α.Compared with single macrophage group,LPS also can’t stimulate macrophage group including macrophage group infected by M.bovis BCG to produce more IL-1,IL-2,IL-18 and IFN-γ.Conclusion LPS can stimulate macrophage to produce more IL-12,TNF-α.That is conducive to the host immune response.It is suggested that LPS and its analogues may have potential for anti-TB drugs,vaccines or their adjuvants.

Key words: Lipopolysaccharide, M.bovis BCG, Macrophage, Cytokines