The interdependent, overlapping, and differential roles of type I and II IFNs in the pathogenesis of experimental autoimmune encephalomyelitis.

Type I IFNs (IFN-α and IFN-β) and type II IFN (IFN-γ) mediate both regulation and inflammation in multiple sclerosis, neuromyelitis optica, and in experimental autoimmune encephalomyelitis (EAE). However, the underlying mechanism for these Janus-like activities of type I and II IFNs in neuroinflammation remains unclear. Although endogenous type I IFN signaling provides a protective response in neuroinflammation, we find that when IFN-γ signaling is ablated, type I IFNs drive inflammation, resulting in exacerbated EAE.