Abstract
A line of human amniotic cells (UAC) was found to yield large amounts of fibroblast interferon (IFN-beta; 100 to 150 IU/10(3) cells) upon induction with Newcastle disease virus (NDV). UAC cells have a doubling time of about 24 h, and do not require foetal calf serum for growth or optimal IFN yield. The IFN produced was shown to be HuIFN-beta by assaying it on homologous and heterologous cells, and by neutralization tests with specific antisera. It could be purified to a specific activity of 0 . 6 X 10(7) IU/mg protein by chromatography on Blue Sepharose. Addition of 8 micrograms poly(A+) RNA from NDV-induced UAC in 100 microliter of reticulocyte lysate resulted in the production of 510 +/- 340 IU/ml of an IFN that was neutralized only by anti-HuIFN- beta serum.