Mouse hepatitis virus (MHV-4, JHM) blocks γ-interferon-induced major histocompatibility complex class II antigen expression on murine cerebral endothelial cells

The regulation of γ-interferon-induced major histocompatibility complex (MHC) class II antigen expression on mouse cerebral endothelial cells by the neurotropic mouse hepatitis virus (MHV-4, JHM) was studied in vitro. The results presented demonstrate that MHV-4 can selectively block γ-interferon-induced class II antigen expression on cerebral endothelial cells. The blocking effect of class II expression occurs in a strain-dependent manner, and is limited to virus-susceptible mouse strains. Virus replication is not required to obtain the blocking effect since UV-inactivated MHV-4 produces the same result. MHV-4 blocking of γ-interferon-induced class II antigen expression is observed at both the cell surface (flow cytometry) and transcriptional level (Norhtern analysis).