Cytokines of the Interleukin (IL)-12 family, consisting of IL-12, IL-23, IL-27 and IL-35, are important regulators in (chronic) inflammatory disorders such as rheumatoid arthritis and multiple sclerosis, but also in cardiovascular diseases.
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).
In this study, we evaluated the efficacy of adeno-associated viral vector (AAV)-delivered IL-27 (AAV-IL-27) and IL-30 (AAV-IL-30) in a murine model of MS. We found that one single administration of AAV-IL-27, but not AAV-IL-30 completely blocked the development of experimental autoimmune encephalomyelitis (EAE).
This was surprising as both TLR3 and IL-10 play protective roles in animal models of MS. Interestingly, combination of TLR3 triggering with the other TLRs, enhanced IL-10 through the modulation of its transcription, via interferon (IFN)-β, but independently of IL-27.
Overall, our data show that IL-27 is a key cytokine in antigen-induced peripheral tolerance and may provide basis for improvement of antigen-specific tolerance approaches in multiple sclerosis and other autoimmune diseases.
Our findings suggest that IFN-β mediates its therapeutic effects in MS at least in part via the induction of IL-27, and that IL-27 may represent an alternative therapy for MS patients that do not respond to IFN-β.
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.
The aim of this review is to highlight the potential areas of IL-27 clinical application, especially the management of neoplastic and viral diseases as well as autoimmune disorders, including rheumatoid arthritis and multiple sclerosis.