This study investigated the effect of a polysaccharide purified from Pholiota nameko (PNPS-1) on the NF-kappa B signaling pathway of murine bone marrow-derived dendritic cells (BMDCs) and relevant mechanisms. The results showed that PNPS-1 could decrease the expression of maturation markers CD40 and CD80 on BMDCs. PNPS-1 also could decrease the mRNA expression of Myd88, TRAF6, TIRAP, IRAKI, IKBKB, NFKB1, NFKB2 and RelA in immature BMDCs determined by RT-PCR, and decreased the IKK beta and P65 production in BMDCs determined by Western blot, and decreased the NF kappa B P65 production determined by ELISA. In addition, the effects of PNPS-1 on BMDCs were significantly impaired by treating the cells with anti-TLR2 antibody prior to PNPS-1 treatment, implying direct interaction between PNPS-1 and TLR2 on cell surface. These results indicate that PNPS-1 regulates BMDCs through TLR2 and downstream NF-kappa B signalings. (C) 2015 Elsevier B.V. All rights reserved.