β-glucan, one of the major cell wall components of Saccharomyces cerevisiae
, has been found to enhance immu-ne functions. This study investigated in vivo and in vitro effects of β-glucan on lymphoproliferation and interferon-γ (IFN-γ) production by splenic cells from C57BL/6 female mice. All experiments were performed with particulate b-glucan derived from S. cerevisiae
. Data demonstrated that both, i.p administration of particulate b-glucan (20 or 100 μg/animal) and in vitro stimulation of splenic cells (20 or 100 μg/ml of culture) decreased lymphoproliferation and IFN-γ production induced by concanavalin A. These results suggest that β-glucan can trigger a down-modulatory effect regulating a deleterious immune system hyperactivity in the presence of a strong stimulus.