Autoimmune disorders associated with gain of function of the intracellular sensor MDA5

Immunity. 2014 Feb 20;40(2):199-212. doi: 10.1016/j.immuni.2013.12.014. Epub 2014 Feb 13.


MDA5 is an essential intracellular sensor for several viruses, including picornaviruses, and elicits antiviral interferon (IFN) responses by recognizing viral dsRNAs. MDA5 has been implicated in autoimmunity. However, the mechanisms of how MDA5 contributes to autoimmunity remain unclear. Here we provide direct evidence that dysregulation of MDA5 caused autoimmune disorders. We established a mutant mouse line bearing MDA5 mutation by ENU mutagenesis, which spontaneously developed lupus-like autoimmune symptoms without viral infection. Inflammation was dependent on an adaptor molecule, MAVS indicating the importance of MDA5-signaling. In addition, intercrossing the mutant mice with type I IFN receptor-deficient mice ameliorated clinical manifestations. This MDA5 mutant could activate signaling in the absence of its ligand but was paradoxically defective for ligand- and virus-induced signaling, suggesting that the mutation induces a conformational change in MDA5. These findings provide insight into the association between disorders of the innate immune system and autoimmunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoimmune Diseases / genetics*
  • Autoimmune Diseases / physiopathology*
  • Cells, Cultured
  • DEAD-box RNA Helicases / genetics*
  • DEAD-box RNA Helicases / metabolism*
  • Disease Models, Animal
  • Interferon-Induced Helicase, IFIH1
  • Interferon-alpha / genetics
  • Interferon-alpha / metabolism
  • Mice
  • Mutation


  • Ifna1 protein, mouse
  • Interferon-alpha
  • Ifih1 protein, mouse
  • DEAD-box RNA Helicases
  • Interferon-Induced Helicase, IFIH1