In vitro effects of polyporus umbellatus polysaccharide on immunosuppressions of Colon26 tumor cells

CUI Cheng; WANG Runtian; ZHI Guocheng; WANG Zhihua; DENG Yuqing; ZHANG Zhengzheng; TONG Hui

Abstract：Objective To study in vitro effects of polyporus umbellatus polysaccharide(PUP)on immunosuppressions of Colon26 tumor cells.Methods Re-cultured supematants of PUP-treated Colon26 and corresponding supernatants of Colon26 without PUP treatment as control were collected.The effects of PUP on five immunosuppressions by Colon26(including NK killing and transformation detected by MTT,as well as the expression levels of IL-2Rα,CD3ε~+ξ~+,and CD3ε~-ξ~+ detected by FCM)were determined.The concentrations of five immunosuppressors(including TGF-β_1,VEGF,IL-4,IL-6,and IL-10)in supernatants were measured by quantitative ELISA.The relationships between the down-regulating effects of PUP on secretions of immunosuppressors and immunosuppressions were determined by multi-correlation analysis.Results All of five immunosuppressors were found in control,while TGF-β_1 was highest.The significant inhibitions of five immune functions were showed.For Colon26 after treated by PUP,the concentrations of TGF-β_1 in the first re-cultured supernatant and its inhibitory effects on five immune functions decreased greatly,while the concentrations of five immunosuppressors in the second re-cultured supernatant and their inhibitory effects on NK killing,IL-2Rα and CD3ε~-ξ~+ expressions increased highly.TGF-β_1 was positively correlated with inhibition of NK killing/transformation and CD3ε~+ξ~+ expression.Conclusion Reducing tumor immunosuppression through decreasing immunosuppressors should be one of anti-tumor mechanisnas of PUP.