Effect of stimulation with combined IL-12 and IL-18 on exosomes secreted by dendritic cells

Objective: To observe the effect of stimulation with combined IL-12 and IL-18 on exosomes secreted by dendritic cells(DCs),and so as to facilitate exploring high-efficiency DC derived exosome(Dex) cancer vaccines.Methods: DCs induced from human peripheral blood mononuclear cells(PBMCs) were stimulated with IL-12+IL-18,IL-12 or IL-18 for the combined group,IL-12 group and IL-18 group respectively;and no stimulant for the control group.Dex was extracted from DCs.The expressions of HLA-DR and CD83 in Dex were detected by Western blotting.CD54,CD80 and CD86 expressions were determined by flow cytometry.The T cell proliferation stimulated by Dex was detected with MTT method.IFN-γ in the T cell supernatant was detected by ELISA.Results: HLA-DR and CD83 proteins were expressed in Dex of all the four groups.The molecule expressions for combined group were CD54(323.67±44.06 vs 246.17±31.91,236.33±33.87,167.67±28.73,P0.05),CD80(406.37±39.18 vs 331.67±36.15,335.67±41.38,260.00±35.58,P0.05),and CD86(390.50±38.06 vs 314.33±36.64,319.00±33.10,246.83±30.55,P0.05),which were higher than those in the IL-12 group,IL-18 group and control group.The T cell proliferation in the combined group(1.98±0.31 vs 1.55±0.23,1.57±0.21,1.10±0.18,P0.05) was higher than that in the IL-12 group,IL-18 group and control group.IFN-γ secreted by T cells in the combined group(436.67±61.8 vs 295.04±40.25,358.18±55.77,225.00±36.44,P0.05) was higher than that in the IL-12 group,IL-18 group and control group.Conclusion: Stimulation of DCs with combined IL-12 and IL-18 can enhance Dex express CD54,CD80 and CD86,promote Dex-induced T cell proliferation and increase IFN-γ secretion by T cells.