Interferon Stimulation by a Double Stranded RNA of a Mycophage in Statolon Preparations

Abstract

PREPARATIONS of statolon derived from fermentation broths of Penicillium stoloniferum are capable of inducing interferon and contain particles with viral morphology^1–2. Interferon inducing activity is separable into a small molecular and a particulate fraction by sucrose density gradient centrifugation. Electron microscopy showed that particles are present only in the particulate fraction. Although earlier results suggested that the activity was associated with a polysaccharide³, this theory was no longer tenable after our discovery and description of virus particles and interferon activity associated primarily with the particles^1–2. Lampson et al.⁴ reported that the active component of helenine, obtained from fermentation broths of Penicillium funiculosum and an inducer of interferon, is a double stranded RNA. Because double stranded RNAs have so far been found only in viruses or in cells infected with RNA virus, we undertook to determine whether the statolon particle contains double stranded RNA. The nature of the small molecular fraction was also examined.