[Effect of erythromycin on macrophage functions]

Recently, it has been suggested that macrolide antibiotics act as immunomodulators. In this study, we evaluated the effect of EM on macrophage function. We used the mouse macrophage cell line, J774.1. The following direct effects of EM on macrophage function were evaluated: chemotaxis to EM, chemokinetic effect by EM, and the effect of EM on macrophage growth. In order to examine the indirect effects of EM on macrophage functions, we preincubated macrophages with several concentrations of EM and then removed the EM. Thereafter, the phagocytosis of beads, cytocidal activity against Candida albicans, and chemotaxis to lipopolysaccharide were evaluated. EM (at the concentration between 0.04 and 0.2 microgram/ml) directly stimulated macrophage chemotaxis and chemokinesis. In addition, EM dose-dependently stimulated the growth of macrophages. EM pretreatment (for 4 hours at the contractions between 0.04 and 0.2 microgram/ml) stimulated macrophage phagocytosis, cytocidal activity against Candida albicans, and chemotaxis to lipopolysaccharide. These results suggest that EM has direct and indirect effects on macrophage functions.