Inhibition of erythroid differentiation of mouse erythroleukemia cells by a macrophage product(s)

Abstract

Conditioned media from established murine macrophage cell lines (RAW264.7, P388D1, and WEHI-3) incubated with endotoxin in a serum-free medium contain an erythroid inhibitory activity (EIA) that inhibited dimethylsulfoxide-induced erythroid differentiation of mouse Friend virus-transformed erythroleukemia cells. Endotoxin itself has no EIA activity. Partial purification of EIA demonstrated that it is distinct from other macrophage products such as IL-1, TGF beta, ECGF, FGF, G-CSF, hepatocyte stimulating factor, interferon, PDGF, and cachectin/TNF. These findings indicate that EIA is a macrophage product distinct from other monokines.