Murine Coronavirus Mouse Hepatitis Virus Is Recognized by MDA5 and Induces Type I Interferon in Brain Macrophages/Microglia

作者：Roth Cross Jessica K; Bender Susan J; Weiss Susan R^*

来源：Journal of Virology, 2008, 82(20): 9829-9838.

DOI：10.1128/JVI.01199-08

The coronavirus mouse hepatitis virus (MHV) induces a minimal type I interferon (IFN) response in several cell types in vitro despite the fact that the type I IFN response is important in protecting the mouse from infection in vivo. When infected with MHV, mice deficient in IFN-associated receptor expression (IFNAR(-/-)) became moribund by 48 h postinfection. MHV also replicated to higher titers and exhibited a more broad tissue tropism in these mice, which lack a type I IFN response. Interestingly, MHV induced IFN-beta in the brains and livers, two main targets of MHV replication, of infected wild-type mice. MHV infection of primary cell cultures indicates that hepatocytes are not responsible for the IFN-beta production in the liver during MHV infection. Furthermore, macrophages and microglia, but not neurons or astrocytes, are responsible for IFN-beta production in the brain. To determine the pathway by which MHV is recognized in macrophages, IFN-beta mRNA expression was quantified following MHV infection of a panel of primary bone marrow-derived macrophages generated from mice lacking different pattern recognition receptors ( PRRs). Interestingly, MDA5, a PRR thought to recognize primarily picornaviruses, was required for recognition of MHV. Thus, MHV induces type I IFN in macrophages and microglia in the brains of infected animals and is recognized by an MDA5-dependent pathway in macrophages. These findings suggest that secretion of IFN-beta by macrophages and microglia plays a role in protecting the host from MHV infection of the central nervous system.

• 出版日期2008-10