Subgrouping immunomodulating ?-glucans by monitoring IFN-? and NO syntheses

(1→3)-β-D-glucan (β-glucan) is a representative microbial product showing activity as a biological response modifier (BRM). Some β-glucan preparations have already been used clinically for cancer therapy but the mechanisms of action are not yet clear. We measured IFN-γ-producing activity of β-glucans in mice and compared this with NO production of macrophages in vivo and in vitro. Monitoring these activities, β-glucans can be separated into at least four subgroups: 1) IFN-γ (+), NO in vivo (+), NO in vitro (+); 2) IFN-γ (+), NO in vivo (+), NO in vitro (–); 3) IFN-γ (+), NO in viva (–), NO in vitro (–); and 4) IFN-γ (–), NO in vivo (–), NO in vitro (–). These facts might be helpful to the molecular understanding of BRM, including β-glucan. Drug Dev. Res. 42:35–40, 1997.