Potential antiinflammatory effects of interleukin 4: Suppression of human monocyte tumor necrosis factor alpha , interleukin 1, and prostaglandin E sub(2)

Stimulated human monocytes/macrophages are a source of mediators such as tumor necrosis factor alpha (TNF- alpha ), interleukin 1 (IL-1), and prostaglandin E sub(2) (PGE sub(2)), which can modulate inflammatory and immune reactions. Therefore, the ability to control the production of such mediators by monocytes/macrophages may have therapeutic benefits, and it has been proposed that glucocorticoids may act in this way. Purified human monocytes, when stimulated in vitro with lipopolysaccharide (LPS) or with LPS and gamma interferon (IFN- gamma ), produce TNF- alpha , IL-1, and PGE sub(2). IL-4 can suppress some parameters of monocyte activation and, as for B cells, have opposite effects to IFN- gamma .