Activation of murine kupffer cells by administration with gel-forming (1-->3)-beta-D-glucan from Grifola frondosa.
The effect of gel-forming (1-->3)-beta-D-glucan on the immunological activities of murine kupffer cells was examined. A branched type gel-forming (1-->3)-beta-D-glucan, GRN, was administered intravenously to mice. GRN associating to kupffer cells was detected by an immunohistochemical technique using anti-GRN antibody. A kinetic study of the activation of kupffer cells revealed that GRN could induce the enhanced production of cytokines and nitric oxide on 4 to 7 d after the administration. The activities are further augmented by adding GRN in the culture. The cytostatic activity of kupffer cells against murine lymphoma, EL-4, was also augmented by a time course similar to nitric oxide production. The cytostatic activity was reduced by adding an inhibitor of nitric oxide synthase, implying that the cytostatic activity of kupffer cells to EL-4 was dependent on nitric oxide. The administration of GRN increased the expression of CD11b, known as a beta-glucan receptor, on kupffer cells at day 7. The above data suggest that GRN could activate murine kupffer cells to enhance the production of cytokines and nitric oxide, and that the activation required 4 or 7 d, at least, after the administration with GRN.