Host genetic factors influence murine cytomegalovirus lung infection and interstitial pneumonitis.

We evaluated the influence of host genetic factors on the course of murine cytomegalovirus (MCMV) lung infection after intranasal inoculation and on the development of interstitial pneumonitis after virus and cyclophosphamide (CP) administration. Susceptibility to virus replication in the lungs of various inbred murine strains was inherited as an autosomal dominant trait, which was associated with the H-2 locus. Similarly, the development of MCMV interstitial pneumonitis was inherited as an autosomal dominant, polygenic trait. Susceptibility to lung infection was necessary, but not sufficient for MCMV interstitial pneumonitis. Non-H-2-associated factors were also needed and probably related to CP metabolism or the character of immune recovery after CP administration. Therefore, inheritable host factors influence both susceptibility to MCMV lung infection and the genesis of MCMV interstitial pneumonitis.