[The effect of polyporus umbellatus polysaccharide on the immunosuppression property of culture supernatant of S180 cells].

AIM: To investigate the effect of polyporus umbellatus polysaccharide (PUPS) on the immunosuppression property of tumor cell line S180 culture supernatant. METHODS: The inhibitory effects of the culture supernatant of S180 cells in the presence or absence of PUPS on the ConA-induced mouse splenocyte proliferation, IL-2 production, killer activity and the reactivity of CTLL-2 cells to IL-2 were detected by MTT colorimetry. The effect of the culture supernatant on the IL-2Ralpha expression on murine splenocytes was detected by flow cytometry. RESULTS: The culture supernatant of S180 cells could strongly inhibit immunity in terms of the above five indexes, while PUPS could reverse the immunosuppression. CONCLUSION: PUPS can offset the immunosuppression of the supernatant from S180 cell culture, which may be mediated by down-regulating the synthesis and/or secretion of immunosuppressive substance by S180 cells.