IL-27 signaling in Tregs was necessary, as transferring Tregs deficient in IL-27Rα or Lag3, a downstream molecule induced by IL-27, was unable to protect mice from experimental autoimmune encephalomyelitis.
Recently, IL-27 was found to play a role in suppressing experimental autoimmune uveitis and experimental autoimmune encephalomyelitis, two animal models that share essential pathological features of human uveitis and multiple sclerosis, respectively.
IL-27 exerts protective effects in autoimmune diseases like experimental autoimmune encephalomyelitis; however, its role in the pathogenesis of osteoporosis remains to be determined.
We immunized wild-type (WT) and IL-27 receptor (WSX-1) knockout mice with MOG<sub>35-55</sub> for induction of experimental autoimmune encephalomyelitis and intravenously (i.v.) injected them with MOG<sub>35-55</sub> after onset of disease to induce i.v. tolerance. i.v. administration of MOG<sub>35-55</sub> reduced disease severity in WT mice, but was ineffective in <i>Wsx</i><sup>-/-</sup> mice.
Our data reveal a new cellular regulatory mechanism of IL-27 that targets DC-mediated immune responses in autoimmune diseases such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE).
Complementary in vivo studies in a mouse model showed that treatment with IFN-β enhanced expression of IL-27, and reduced IL-17 in the CNS and periphery and attenuated the clinical signs of experimental autoimmune encephalomyelitis (EAE).
By generating mice deficient for the p28 subunit of IL-27, we showed that IL-27 regulated the severity of delayed-type hypersensitivity response and EAE through its effects on Th17 cells.