Interferon Synthesis in X-irradiated Animals

Summary

C₃H/He mice were exposed to 1000 R whole-body x-irradiation. Circulating-interferon levels induced in these animals after intravenous injection of Sindbis or Newcastle disease virus were reduced to less than 10 per cent of their normal values. The circulating-interferon-producing capacity could be restored by treatment with isologous bone-marrow cells, immediately after irradiation. The degree of restoration of interferon formation was closely related to the degree of restoration of haemopoietic function, as indicated by experiments where irradiated animals were treated with either a minimal (2 × 10⁵) or an optimal (10⁷) number of isologous marrow cells. This suggested a direct relationship between bone-marrow function and the circulating-interferon-producing system. Evidence that circulating-interferon-producing cells are largely derived from bone-marrow was obtained by restoring irradiated C₃H/He mice with Wistar rat marrow. In these rat to mouse chimaeras, circulating interferon, induced by either Sindbis or Newcastle disease virus, had the species specific characteristics of rat interferon.