The immunomodulatory effect of LPS, laminaran and sulphated laminaran [β(l,3)‐D‐glucan] on Atlantic salmon,<i>Salmo salar</i>L., macrophages<i>in vitro</i>

Abstract

Abstract. The stimulatory effect of LPS ( Vibrio anguillarum ), laminaran and sulphated laminaran, aqueous soluble β(1,6)‐branched β(l,3)‐D‐glucan obtained from Laminaria hyperborea , on head kidney macrophages of Atlantic salmon, Salmo salar L., is reported. The macrophages, after stimulation with LPS or laminaran, showed pronounced spreading, membrane ruffling and increased organellc content when examined by light microscopy. LPS stimulation induced enhanced phagocytic and pinocytic activity, higher intraccllular production of superoxide anion, and higher activity of acid phosphatase compared to control cells. Native laminaran stimulated the cells to pinocytose more fluid phase, increase the intracellular production of superoxide anion and to elevate the activity of acid phosphatase. Sulphated laminaran induced higher production of superoxide anion and higher activity of acid phosphatase by macrophages than in control cells.