Multifactorial protective mechanisms to limit viral replication in the lung of mice during primary murine cytomegalovirus infection.

In this article, we investigated the protective host immune mechanisms against acute murine cytomegalovirus (MCMV) infection. For this purpose, we used various knockout mice lacking molecules, which include interferon-gamma (IFN-gamma), interferon-gamma receptor (IFN-gamma-R), interferon regulatory factor-1 (IRF-1), inducible nitric oxide synthase (iNOS), and perforin. We also used mutant mice lacking Fas molecule. When we infected these mice with MCMV and determined the viral titers in their lungs at different time points, we found that IFN-gamma, IFN-gamma-R, IRF-1, iNOS, and perforin-deficient mice developed significantly higher titers of infectious MCMV in the lung, compared to those observed in their respective wild-type controls. In the lungs of Fas-mutant mice, viral titers were similar to those obtained in wild-type mice.