Direct Effects of Activin A on the Activation of Mouse Macrophage RAW264.7 Cells

Macrophages play critical roles in innate immune and acquired immune v/a secreting pro-inflammatory mediators, phagocytosing microorganisms and presenting antigens. Activin A, a member of transforming growth factor （TGF-β） superfamily, is produced by macrophages and microglia cells. In this study, we reported a direct effect of activin A as a pro-inflammatory factor on mouse macrophage cell line RAW264.7 cells. Our data revealed that activin A could not only increase IL-1β and IL-6 production from RAW264.7 cells, but also promote pinocytic and phagocytic activities of RAW264.7 cells. In addition, activin A obviously up-regulated MHC Ⅱ expression on the surface of RAW264.7 cells, whereas did not influence MHC I expression. Activin A also enhanced CD80 expression, which is a marker of activated macrophages, but did not influence RAW264.7 cell proliferation. These data suggest that activin A may regulate primary macrophage-mediated innate and acquired immune response via promoting the activation of rest macrophages.