Immunomodulation of RAW264.7 macrophages by GLIS, a proteopolysaccharide from Ganoderma lucidum

The immunomodulatory effect of Ganoderma lucidum immunomodulating substance (GLIS) on macrophages has been investigated as part of on-going research into the anti-cancer properties of Ganoderma lucidum. Proliferation of bone marrow macrophages (BMMs) was enhanced by GLIS in a dose-dependent manner. Microscopic examination revealed that numerous GLIS-treated RAW264.7 macrophages were enlarged and formed pseudopodia. Exposure of RAW264.7 macrophages to GLIS resulted in significant increases in NO production, induction of cellular respiratory burst activity, and increased levels of IL-1β, IL-12p35 and IL-12p40 gene expression. Our data indicate that GLIS activates the immune system by modulating cytokine production.