The effect of experimental infection of mice with encephalomyocarditis (EMC) virus on interferon production by alveolar and peritoneal cells in vitro.

After infection of mice with EMC virus, dose-dependent increase or decrease of the synthesis of in vitro Newcastle disease virus (NDV)-induced interferon was observed in alveolar and peritoneal cells. It was shown that peritoneal cells from mice with mild course of the infection (infecting dose 0.2-1.0 LD50 per mouse) produce interferon in vitro on the same level as the control cells. Alveolar cells isolated from the same mice shortly after infection exhibited increased interferon production in vitro as compared with the analogous cells isolated from the non-infected mice. Acute, EMC-induced infection in mice (infecting dose 5.0 LD50 per mouse) caused suppression of interferon synthesis in vitro by both peritoneal and alveolar cells, which intensified together with the progression of the disease.