IFN- γ Induction by SCG,1,3- β -D-Glucan from Sparassis crispa,in DBA/2 Mice In Vitro

Abstract

Sparassis crispa Fr. in an edible mushroom recently cultivable in Japan. A branched β-glucan from S. crispa (SCG) is a major 6-branched 1,3-β-D-glucan showing antitumor activity. In this study, we examined interferon-γ (IFN-γ) induction by SCG from splenocytes in DBA/2 mice in vitro. In the splenocytes derived from almost all inbred strains of mice except for DBA/1 and DBA/2 mice, IFN-γ production was not induced by SCG. The breeder and genders of DBA/2 mice showed no influence on IFN-γ induction by SCG. On the other hand, the magnitude of IFN-γ induction was lower in young mice than in their older counterparts. IFN-γ was induced by SCG in adherent splenocytes, but IFN-γ production was most significantly increased by SCG in instances involving coexistence of adherent and nonadherent splenocytes. In fact, inhibition of cell-cell contact reduced IFN-γ induction by SCG. In addition, interleukin-12 p70 (IL-12p70) was induced by SCG in DBA/2 mice. It was suggested that soluble factors and cell-cell contact mediate synergistic effects on SCG-induced IFN-γ production.