Analysis of the interferons induced in mice in vivo and in macrophages in vitro by Newcastle disease virus and by polyinosinic-polycytidylic acid.

C57BL/6 mice or pure cultures of their macrophages were inoculated with Newcastle disease virus (NDV) or poly(I).poly(C) to induce interferons (IFNs) that were separated on CH-Sepharose 4B columns. The elution profiles of different activity peaks were compared. All preparations induced in vivo showed the same pattern but the relative proportions of the IFN activities varied. In vitro poly(I).poly(C)-induced IFN showed two peaks after separation by the column, and three peaks were found when NDV-induced IFNs were separated. When IFN induced by NDV in vitro was used to determine the molecular weight, activities were observed in three molecular weight ranges. The smallest one with 18,000 daltons was neutralized by anti-IFN-alpha and represented about 7% of the total activity. The activities of molecular weights 24,000 daltons and 29,000-31,000 daltons were neutralized by anti-IFN-beta. Poly(I).poly(C)-induced IFN in vitro showed two molecular weight ranges, 26,000 daltons and 40,000 daltons, and both were neutralized by anti-IFN-beta. IFN induced in serum by NDV at 3 h had molecular weights of 18,000 daltons neutralized by anti-IFN-alpha and 26,000-30,000 daltons neutralized by anti-IFN-beta. Both IFN subtypes were represented at equal quantities. Serum IFN found in the serum after 8 h had three molecular weight ranges: 18,500-19,500 daltons neutralized by anti-IFN-alpha containing 80% of the total IFN amount, 26,000-27,000 daltons, and 38,000 daltons both neutralized by anti-IFN-beta and containing 20% of the IFN.(ABSTRACT TRUNCATED AT 250 WORDS)