Conformation dependency of nitric oxide synthesis of murine peritoneal macrophages by beta-glucans in vitro (vol 52, pg 1, 1996)

We have already demonstrated that various activities including NO (nitric oxide) synthesis in vivo were significantly different between triple helical (SPG) and single helical (alkaline-treated SPG, SPG-OH) beta-glucans, and that beta-glucan-mediated NO synthesis was associated with increased gene expression of IFN-gamma. In this study, we analyzed beta-glucan-mediated NO production in vitro with the concomitant use of IFN-gamma. Proteose peptone-elicited peritoneal macrophages (PM) were collected from male C3H/HeJ mice and cultured with beta-glucans in the presence or absence of IFN-gamma for 24 h. It was found that SPG-OH, but not SPG, enhanced NO synthesis in vitro, especially in the presence of IFN-gamma. Concentrations of interleukin-1 alpha, -6 and TNF-alpha in the culture supernatant of SPG-OH were significantly higher than those in that of SPG. Membrane-associated IL-1 alpha was also high with SPG-OH. Cytokine productivity of PMs, as well as NO synthesis, was elevated in the presence of IFN-gamma. These facts intensely suggest that the single helical conformer of beta-glucan (SPG-OH) is dominant in cytokine production and subsequent NO synthesis.