Production of macrophage colony-stimulating factor (M-CSF) by human articular cartilage and chondrocytes. Modulation by interleukin-1 and tumor necrosis factor α

Abstract

A specific radioimmunoassay was employed to demonstrate that human articular cartilage and chondrocyte monolayers in organ and cell culture, respectively, produce macrophage colony-stimulating factor (M-CSF) in response to stimulation with interleukin-1α (IL-1α), IL-1β, tumor necrosis factor α(TNFα) and TNFβ. Optimum doses were 10-100 U/ml for IL-1 (0.06-0.6 nM IL-1α; 0.02-0.2 nM IL-1β) and 1-10 nM for TNFα. Low levels of M-CSF were observed in the supernatants of nonstimulated cultures while increased levels of M-CSF in response to IL-1α and TNFα were detected following 2 h exposure to the cytokines. IL-1α and TNFα did not show synergy for the production of M-CSF when both cytokines were ad..