[#1993-05] β-Glucans Inhibitory Effect of Beta-Glucans on Zymosan-Mediated Hydrogen Peroxide Production by Murine Peritoneal Macrophages in Vitro, Y. Adachi et al.

β-Glucans  Inhibitory Effect of Beta-Glucans on Zymosan-Mediated Hydrogen Peroxide Production by Murine Peritoneal Macrophages in Vitro

Adachi, Y, Ohno, N, Yadomae, T

Laboratory of Immunopharmacology of Microbial Products, Tokyo College of Pharmacy

Effects of the pretreatment of murine peritoneal macrophages with several polysaccharides on the production of H₂O₂ induced with unopsonized zymosan were examined. Pretreatment with most of (1->3)-β-D-glucans for 6h at 37deg C inhibited the zymosan-mediated H₂O₂ production by macrophages. The phorbol myristate acetate (PMA)-mediated H₂O₂ production was not affected by the pretreatment. The pretreatment of macrophages with (1->3)-β-D-glucans decreased the ability to ingest unopsonized zymosan, but did not affect the ingestion of IgG-coated sheep red blood cells (IgG-SRBC). These results suggested that the pretreatment with (1->3)-β-D-glucans interfered with the interaction of macrophages to zymosan and that the occupation of the receptor for the (1->3)-β-D-glucans inhibited zymosan-mediated production of H₂O₂ by macrophages. Chemical modification by substitution with carboxymethyl groups or hydroxyethyl groups of a (1->6)-branched (1->3)-beta-D-glucan reduced the inhibitory effect of preteatment on zymosan-mediated H₂O₂ production. The above results indicated the possibility that murine peritoneal macrophages possess certain receptors for beta-anomeric glucans, and one ligand specificity of the receptors is to restrict the intact 1->3)-β-D-glucosyl backbone.