Modulation of the immune response of porcine neutrophils by different β-glucan preparations

beta-glucans of bacterial and fungal origin are known immuno-modulators, but data in the literature also indicate that lichen and cereal-derived beta-glucans may have immuno-modulatory functions. The aim of the current study was to test the effect of different sources of beta-glucans on neutrophils in an ex-vivo whole blood stimulation assay. Whole blood samples were either treated with curdlan, a linear beta-(1 -> 3)-D-glucan from the non-pathogenic Alcaligenes faecalis, lichenan, a mixed linked beta-(1 -> 3), (1 -> 4)-D-glucan from Islandic moss (Cetraria islandica) or zymosan, prepared from yeast cell walls and being rich in branched beta-(1 -> 3),(1 -> 6)-D-glucan. The blood cell were either stimulated alone or in combination with lipopolysaccharide (LPS) and compared with LPS-treated and untreated control samples. Preliminary results show that Zymosan, had a different effect than lichenan and curdlan, on the surface expression of Toll-like Receptor (TLR) 2 and 4, but not significantly on the signal regulatory protein SIRP alpha after a stimulation either alone or in combination with LPS. Thus, branching may appear to be important for the different effect, but an effect of impurities in the Zymosan preparation cannot be ruled out. (C) 2010 Elsevier B.V. All rights reserved.