ABSTRACT
Objective:To study the regulatory effects of Ligustrazine Hydrochloride(LHC)on tumor-induced immunosuppression by Colon26 cells in vitro.Methods:Colon26 cells were cultured for 48 h in the presense of LHC and either the cell fraction or the cultural supernatants was collected,with the untreated Colon26 cells as control for the study.The down-regulating effects of LHC on tumor immunosuppressions (including the suppressed NK killing and ConA induced transformation of murine spleen cells detected by MTT,and the reduced expression levels of IL-2R?,CD3?+?+ and CD3?-?+ detected by FCM) were determined.The concentrations of immunosuppressive cytokines,including TGF-?1,VEGF,IL-4,IL-6 and IL-10,in the supernatants were analyzed by quantitative ELISA.The relationship among the down-regulatory effects of LHC on secretion immunosuppressive cytokines and tumor immunosuppressions were evaluated by multiple linear regression analysis.Results:All of the cytokines assayed were found in the supernatant of Colon26 treated without LHC,in which TGF-?1 was the highest,and the significant inhibition of five immune functions mentioned above was showed.To the Colon26 treated by LHC,the concentrations of TGF-?1,IL-6 and IL-10 in the first re-cultured supernatant and its inhibition of five immunol functions decreased greatly.The concentrations of TGF-?1 and IL-6 in the second re-cultured supernatant and its inhibitions of transformation,CD3+?+ and CD3-?+resumed highly.The positive correlations existed between TGF-?1 and inhibition of immunol functions except for transformation,between IL-6 and inhibition of transformation or CD3-?+,between IL-10 and inhibition of NK killing or IL-2R? or CD3+?+,respectively.Conclusion:LHC can exert down-regulate effects on Colon26 secretion of immunosuppressors and its tumor immunosuppression.Reducing tumor immunosuppression of Colon26 through decreasing its secretion of immunosuppressors should be one of anti-tumor mechanisms of LHC.