Purification of human lymphoblastoid interferon by a simple procedure with high yields

Human Namalwa cell interferon, induced by Sendai virus and composed of a single species with molecular weight of 17,000, was purified to 4.5 X 10(8) international reference units/mg of protein by a combination of salt precipitation, ion exchange chromatography, metal chelate chromatography, hydrophobic chromatography, and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. By immunization of a rabbit with this purified interferon and by extensive absorption with Namalwa cells and an impurity column, highly specific antibody was obtained. Namalwa cells, treated with 5-bromo-2'-deoxyuridine, produced 10-fold more interferon upon induction by Sendai virus. Interferon in this case consisted of heterogeneous species with molecular weight ranging from 15,000 to 24,000. These heterogeneous interferon molecules were purified to 7.6 X 10(8) international reference units/mg of protein by successive chromatography using immobilized highly specific rabbit anti-interferon antibody, Blue Sepharose, and immobilized goat anti-rabbit IgG antibody. The overall recovery of interferon activity was 72%, and the purity of the final preparation was ascertained by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate.