Abstract
Background Ganoderma lucidum is a medicinal mushroom exhibiting numerous health benefits primarily based on strong immunostimulatory effects. The aim of the study was to investigate if there were differences in effects of extracts of commercially (GC) and alternatively (wheat straw) (GA) cultivated G. lucidum basidiocarps on properties of peritoneal macrophages (PM) and monocyte-derived dendritic cells (MoDCs).
Methods Differences in immunomodulatory effects of GC/GA extracts were studied. Viability of treated PMs, their adhesive and phagocytic capability and capacity to produce reactive oxigen species (ROS) and NO was tested. Immature MoDCs generated from human monocytes were treated with poly I:C (10.0 µg/ml) and loxoribine (34.0 µg/ml), a selective TLR3 and TLR7 agonists, respectively, and with/without GC/GA extract (100.0 µg/ml). The effect of each combination on phenotypic properties, cytokines production by MoDCs, and their proliferation and Th polarizing capacity was studied.
Results GA extract stronger stimulated metabolic and phagocytic activity of PMs, their adhesion capability and ability to produce ROS and NO compared to GC. Both tested extracts significantly increased allostimulatory and Th1 polarization capacity of simultaneous TLR3 and TLR7-activated MoDCs, but GA extract was more effective.
Discussion The extract of alternatively cultivated G. lucidum basidiocarps increased production of ROS and NO by TLR4 stimulated PMs and up-regulated production of certain cytokines as well as allostimulatory and Th1 polarization capacity of MoDCs. GA extract could be a potent immunostimulatory agent for activation of MoDCs with simultaneous engagement of TLRs that seems to be a promising strategy for preparation of DC-based anti-tumor vaccines.