Motonori Okabe

Interferon-γ-activated macrophages release interleukin-1 α to increase tube formation from endothelial cells of rat aorta

Abstract Interferon (IFN)-γ (160 and 460 pM)-treated peritoneal macrophages (Mo) increase tube formation from subcultured aortic endothelial cells (EC) of rat in type I collagen gel (Kobayashi et al., Immunopharmacology, 27: 23, 1994). The present study was carried out to identify factors released from these M0. Interleukin (IL)-lα, platelet-derived growth factor (PDGF)-BB and basic fibroblast growth factor (bFGF) increased tube formation, and their 50% effective concentrations were 0.46, 6.4 and 140 pM, respectively. A polyclonal anti-mouse IL-1 α antibody (0.33%) inhibited 57.7 ± 6.5% of the activity of conditioned medium (CM) from IFN-γ-treated Mo, but not from medium of basal Mo or EC. A monoclonal anti-human bFGF antibody (20 ng/ml) inhibited both the activities of CM from IFN-γ-treated and basal Mo by 43.2 ± 15.0% and 46.7 ± 15.9%, respectively. However, a polyclonal anti-human PDGF-BB antibody (0.33%; 3.3 μg/ml) did not inhibit either activity of Mo. These results demonstrate that the effect of IFN-γ-treated Mo on tube formation was caused by released IL-1 α. The release of IL-1 α was dependent on the action of IFN-γ, a different mechanism from those of bFGF and PDGF-BB.