Role of cytokines in the maturation and function of macrophages. Effect of GM-CSF and IL-4.

Abstract

Macrophages and monocytes that infiltrate into chronic inflammatory sites might be influenced by cytokines such as GM-CSF, IL-3, IL-4 and IFNthat are abundant in these sites. Granulocyte Macrophage Colony Stimulating Factor (GM-CSF), is a glycoprotein which is characterized by its capacity to stimulate cell precursors in the bone marrow to undergo proliferation and differentiation into granulocytes and macrophages (Metcalf 1985, Golde and Gasson. 1988). Granulocyte-macrophage CSF is secreted by various cell types, and its production might be enhanced by bacterial products (Chodakewitz et al 1988), and by cytokines such as Interleukin 1 (Zucali et al 1986, Sieff et al 1987, Fibbe et al 1988, Herrmann et al 1988), Interferon (Piacibello et al 1985), and TNF(Lu et al 1988, Munker et al 1986). GM-CSF which is present in chronic inflammatory sites (Williamson et al 1988, Xu et al 1989) was implicated as a key cytokine in inflammatory joint disease (Campbell 1998). The role of GM-CSF as a proinflammatory cytokine was further substantiated by the findings that GM-CSF deficient mice exhibited an attenuated production of inflammatory cytokines i n response to lipopolysacchauide (LPS) (Basu 1997).