Antiproliferative activity of highly purified mouse interferon: brief communication.

The antiproliferative effect of mouse L-cell interferon, purified by bovine serum albumin--agarose chromatography (which yields a sp act of 3 X 10(8) international reference U/ml protein), and its two subcomponents, obtained by CH-Sepharose 4B chromatography, has been studied in Balb/3T3 fibroblast cultues. Four to 10 international reference U of interferon/ml resulted in a 50% inhibition of DNA synthesis and cell growth, as determined by the incorporation of [3H]thymidine and cell counts, respectively. Hence the degree of inhibition produced by the purified interferon preparations was comparable to that produced by the original crude interferon (sp act, 1.5 X 10(6) international reference U/mg protein). Our results, obtained with L-cell mouse interferon purified by two novel affinity ligands, provided further evidence linking the antiviral and antiproliferative activities of this molecule.