Replication of mumps virus in mouse: transient replication in lung and potential of systemic infection.

A mumps virus strain, which replicated in mouse lung after aerosol inhalation, was obtained by selective replication of a wild strain in L929 cells and by further passaging in mice by intraperitoneal inoculation. All of infected mice survived and rechallenge of the survived mice with the same virus resulted in no virus growth in the lung. Treatment of infected mice with antiserum against interferon (IFN) or asialo GM1 delayed virus clearance from lung. Mice at 5 weeks of age were also sensitive to the virus as well as those at 1 week. When injected intravenously, the virus could grow not only in lung but also in salivary glands, heart and spleen. Furthermore, the virus replicated in liver, spleen, pancreas and testis after intraperitoneal inoculation. Antibody response of mice infected by aerosol inhalation was slower than that of intraperitoneally infected ones in either IgG or IgM production. These results indicated that the adapted virus replicated in mouse lung by a natural route of infection and had a potential to cause systemic infection in mouse.