Research on the action mechanism of toxoplasma gondii-induced IL-12 production in human THP-1 cells

doi:10.3969/j.issn.1002-7386.2018.12.001

Abstract：Objective To investigate the action mechanism of toxoplasma gondii-induced IL-12 production in human THP-1 cells. Methods The cultured human monocytic cells series THP-1 cells were divided into control group and infection group. The THP-1 cells in infection group were stimulated with Toxoplasma gondii,then the levels of cytokine-IL-12 in cell culture supernatant were detected in both groups by ELISA,moreover,the expression levels of IL-12 p35 and p40 gene mRNA were measured in both groups by real-time quantitative PCR ( RT-PCR) . The three different length of IL-12 promoter region of plasmids were successfully constructed, which were transfected into RAW264. 7 cells, and the fluorescence intensity was detected by fluorescence detector. Results The levels of IL-12 in culture supernatant in infection group were increased significantly. As compared with those in control group, the expression levels of p35 and p40 gene mRNA in infection group were significantly increased (P<0. 05). The three different length of IL-12 promoter region of plasmids were successfully constructed,which were transfected into RAW264. 7 cells. As compared with that in control group,the fluorescence intensities of p35 ( -1,080~1bp)/PxP2 and p35 ( -1,080~ -20bp)/PxP2 of plasmids were significantly increased (P<0. 05), however,there was no significant difference in p35 ( -1,080~ -50bp)/PxP2 plasmid luciferase activity between two groups. Conclusion The levels of IL-12 in THP-1 cells after stimulated with Toxoplasma gondii are increased significantly,which may be caused by the -20~ -50 core area of IL-12 promoter.