Interferon Induction by Viruses. XX. Acid-Labile Interferon Accounts for the Antiviral Effect Induced by Poly(rI)·Poly(rC) in Primary Chick Embryo Cells

Abstract

Primary chick embryo cells which were "aged" in vitro and exposed to poly(rI) · poly(rC) developed a disproportionately high degree of resistance to virus challenge in relation to the amount of conventional acid-stable interferon (IFN) produced. Cells were often highly resistant after exposure to a few nanograms of poly(rI) · poly(rC) which gave rise to little or no acid-stable IFN. Study of the mechanism(s) responsible showed that this antiviral state was not due to the double-stranded ribonuclease induced in parallel, nor to residual poly(rI) · poly(rC) (which this ribonuclease destroyed), but to the production of a hitherto undescribed acid-labile chicken IFN.