A polysaccharide, extract from Grifola frondosa, induces Th-1 dominant responses in carcinoma-bearing BALB/c mice.

A polysaccharide, designated as the D-fraction, extracted from maitake (Grifola frondosa), was reported to have anti-tumor effects by activating macrophages and T cells in C3H/HeN mice in which a Th-1 dominant response was established. In this study using BALB/c mice in which a Th-2 response is genetically dominant, D-fraction reduced the expression of Th-2 cytokine interleukin (IL)-4 but markedly increased the expression of Th-1 cytokine interferon (IFN)-gamma in CD4(+) T cells and also increased IL-12p70 production as well as IFN-gamma production by antigen-presenting cells (APCs), suggesting that D-fraction promotes the differentiation into Th-1 cells of CD4(+) T cells through enhancement of IL-12p70 production by APCs.