Induction of macrophage DNA synthesis in vitro, by non-immunological inflammatory sera: effect of irradiation and thymus or bone marrow cell reconstitution.

The mitogenic activity on macrophages of acute inflammatory serum is increased when this serum is obtained from irradiated rats. Transfer to irradiated rats of normal syngeneic thymic or bone marrow cells enhances the mitogenic activity of inflammatory serum. The enhancement of mitogenic activity is more pronounced after transfer of cells harvested from rats with an acute inflammatory reaction. It is postulated that the mitogenic activity of inflammatory serum could be related to both thymic and bone marrow cells and that this cellular activity is enhanced when inflammation is present.