Particulate β-glucan induces TNF-α production in wound macrophages via a redox-sensitive NF-κβ-dependent pathway

Glucans are known to promote wound repair. Noncellulosic beta-glucans are recognized as potent immunological activators. beta-Glucans are generally safe and are known to attenuate the rate of postoperative infection. Glyc101 is a particulate beta-glucan isolated from Saccharomyces cerevisiae. In this study, the hypothesis that Glyc101 regulates wound macrophage function was tested. Glyc101 induced tumor necrosis factor (TNF) alpha transcription in macrophages isolated from murine wound site. Multiplex assay identified interleukin (IL)-10 and TNF alpha as two cytokines that are induced by Glyc101 in human blood monocyte-derived macrophages. Glyc101-induced TNF alpha production was observed to be mediated via the TLR-2 and dectin-1 receptors, receptor tyrosine kinases and NF kappa B activation. In murine wound macrophages, Glyc101 potentiated phorbol 12-myristate 13-acetate-induced respiratory burst. In vivo, implantation of Glyc101-enriched polyvinyl alcohol-sponges at the wound-site induced TNF alpha expression in macrophages. Consistently, Glyc101 induced TNF alpha expression in wound-site macrophages isolated from two patients with chronic wounds. These observations establish the translational significance of the net findings of this study. Activation of wound macrophages by Glyc101 represents one of the potential mechanisms by which this beta-glucan may benefit chronic wounds where inefficient inflammatory response is one of the underlying causes of impaired healing.