The effect of a protein-bound polysaccharide from Coriolus versicolor on immunological parameters and experimental infections in mice.

The influence of PSK, a protein bound polysaccharide from Coriolus versicolor on various immunological parameters was studied, PSK was found to enhance B cell activity as measured by the spleen plaque-forming cell assay in mice, and to stimulate mouse macrophages as determined by an enhancement of carbon clearance and an increase in the phagocytosis of opsonized sheep red blood cells by peritoneal mouse macrophages in vitro. The activation of mouse macrophages by PSK appeared to correlate with the therapeutic effects of the compound. In mice made granulocytopenic with cyclophosphamide and subsequently infected with a variety of garm-negative pathogens or with Candida albicans, PSK prolonged the average survival time of the animals. The compound also led to a drastic increase in the number of animals surviving such experimental infections as compared to untreated controls. Possible mechanisms responsible for these protective effects by PSK are discussed.