Stifter, S.A. et al. Cell Rep. 29, 3539–3550 (2019)

Interferons (IFN) are cytokines involved in the defense against infection. Although the role of IFN is well known, the identity and tissue distribution of IFN-responsive cells in vivo remain poorly defined, mainly because the only IFN signaling reporter mouse available (the Mx2-luciferase mouse) could not detect the IFN response at the level of individual cells.

In a new study, investigators from the University of Sydney describe an immunity-related GTPase m1 (Irgm1) reporter mouse strain (M1Red) allowing the visualization of IFN-responsive cells in vivo following inoculation with recombinant IFNs or influenza A virus. The Irgm1 gene was selected to drive dsRed expression because IRGM1 is expressed in both hematopoietic and non-hematopoietic cells and its expression is strongly induced by different types of IFNs.