Genetic resistance to lethal Sendai virus pneumonia: virus replication and interferon production in C57BL/6J and DBA/2J mice.

Resistant C57BL/6J and susceptible DBA/2J mice were exposed to aerosols of Sendai virus and killed at intervals to 12 days. Lungs were removed and assayed for infectious virus and interferon. Mean virus titers were 6 to 400 times higher in DBA/2J mice than in C57BL/6J mice 3 to 10 days after exposure. Mean interferon titers were 10 to 140 times higher in DBA/2J mice than in C57BL/6J mice 4 to 7 days after exposure. These results suggest that genetic resistance to the lethal effects of Sendai virus is expressed through control of viral replication within the first 72 hours of infection and that early expression of inherited resistance is not regulated by interferon.