The effect of synthetic double-stranded polyribonucleotides on haemopoietic colony-forming cells in vivo

Abstract

Intraperitoneal inoculation of 100 μg Poly I—Poly C resulted in an an eight-fold increase in spleen colony forming cells by the sixth day after inoculation. The same dose of Poly AU resulted in a negligible cellular response and no increase in the level of colony stimulating factor in the serum. The colony stimulating activity of serum after inoculation of Poly I—Poly C was increased, but assay of this increase in early sera was complicated by the presence of a colony inhibitor. Some properties of inhibitor-containing sera were investigated and consideration given to the possibility that the colony inhibitor is related to interferon.