Researchers Identify NMI as A New Negative Type I IFN Production Regulator

Viral infection triggers innate immune responses, leading to the production of type I IFNs including IFN-β and many IFN-α species, which are essential in inducing host antiviral responses. These responses must be tightly controlled to prevent harmful effects resulting from excessive activation. Now, scientists from Chinese Academy of Sciences (CAS) identified N-Myc and STATs interactor (Nmi) as a new negative regulator of virus-triggered type I IFN production, offering an update of negative regulation network.

Molecules regulating the virus-triggered signaling pathway by targeting master pathway components like VISA, TBK1, IRF7, orchestrate the regulatory network to guarantee the immune balance. Dr. WANG Jie and YANG Bo from SUN Bing’s lab at Shanghai Institute of Biochemistry and Cell Biology, CAS, found that Nmi could interact with IRF7 and inhibit virus-triggered type I IFN production. Enhanced production of IFNs resulting from Nmi knockdown was sufficient to protect cells from infection by vesicular stomatitis virus.

In addition, Nmi promoted the K48-linked ubiquitination of IRF7 and the proteasome dependent degradation of this protein. In vivo virus challenge assay showed an impairment of antiviral responses in Nmi-transgenic mice.

This study entitled ‘Negative Regulation of Nmi on Virus-Triggered Type I IFN Production by Targeting IRF7’ has been published online in The Journal of Immunology on Aug 16^th, 2013. It was supported by research grants from the Ministry of Science and Technology of China, National Natural Science Foundation of China.