Platelet-Derived Growth Factor (PDGF) Inhibits Antiviral and Anticellular Action of Interferon in Synchronized Mouse or Human Cells

Abstract

Antiviral [vesicular stomatitis or encephalomyocarditis viruses] and anticellular actions of purified mouse or human interferon were inhibited in quiescent, monolayer cultures of mouse or human fibroblasts (3T3 and FS-4) stimulated for growth by PDGF [platelet-derived growth factor]. In asynchronous cell cultures the antagonistic effect of PDGF towards interferon was much less evident. Optimal syncrhonization of cells for division was obtained by density inhibition and incubation of the confluent cell monolayers in low serum medium for 24 h and in 5% platelet-poor plasma serum (PPPS) medium for a further 24 h at 37.degree. C. Under appropriate conditions pure epidermal growth factor and fibroblast growth factor also acted as antagonists of interferon. Interferons and growth factors apparently are 2 families of hormones with directly opposite effects.