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 a ctivities of murine kupffer cells was examined. A branched type gel-fo rming (1-->3)-beta-D-glucan, GRN, was administered intravenously to mi ce. GRN associating to kupffer tells was detected by an immunohistoche mical technique using anti-GRN antibody. A kinetic study of the activa tion of kupffer cells revealed that GRN could induce the enhanced prod uction of cytokines and nitric oxide on 4 to 7d after the administrati on. 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 product ion. The cytostatic activity mas reduced by adding an inhibitor of nit ric oxide synthase, implying that the cytostatic activity of kupffer c ells 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 activat e murine kupffer cells to enhance the production of cytokines and nitr ic oxide, and that the activation required 4 or 7 d, at least, after t he administration with GRN.