Highly Expressed Dectin-1 on Bone Marrow-Derived Dendritic Cells Regulates the Sensitivity to [beta]-Glucan in DBA/2 Mice

Sparassis crispa β-glucan (SCG) is a major six-branched 1,3-β-D-glucan in S. crispa Fr. showing antitumor activity. We previously found that DBA/1 and DBA/2 mice are highly sensitive to SCG in vivo and in vitro. In this study, we investigated the effect of SCG on bone marrow-derived dendritic cells (BMDCs) in DBA/2 mice in vitro. SCG increased the expression of CD80, MHC class I and MHC class II molecules on the cell membrane of BMDCs. SCG induced BMDCs to produce interleukin-12p70 (IL-12p70), IL-6, and tumor necrosis factor-α (TNF-α). The magnitude of cytokine induction by SCG in DBA/2 mice was higher than that in C57BL/6, BALB/c, C3H/HeN, and C3H/HeJ mice. The expression level of the β-glucan receptor, dectin-1, on BMDCs in DBA/2 mice was also highest in DBA/2 among these mice. Blocking dectin-1 significantly inhibited the induction of TNF-α production by SCG. Taken together, these results suggest that the BMDCs from DBA/2 mice are highly sensitive to the induction of cytokine production by SCG in vitro, and that this sensitivity is related to the expression level of dectin-1.