IL-27: Friend or Foe in the Autoimmune Diseases

Background: Autoimmune diseases, with emerging clinical concerns, are caused by imbalances in immune system functions. Cytokines are critical components of the immune system produced by various immune and non-immune cells. Objective: We will review the newly-introduced cytokine known as interleukin-27 (IL-27), which has both pro- and anti- inflammatory roles in immunity. Methods: Literature review of the field of immunology and cytokines in autoimmune diseases. Results: IL-27 alters the balance between the different types of T helper (Th) cells through reduction or promotion of their responses to autoimmune diseases including multiple sclerosis, ulcerative colitis, inflammatory bowel disease, rheumatoid arthritis, psoriasis, autoimmune diabetes, systemic lupus erythematosus, Sjogren's syndrome, Behcet’s disease, and autoimmune aplastic anemia. Conclusions: The functions of IL-27 are currently unclear because it appears to affect different cells, cytokines, and signaling pathways differently. Further investigations are needed to clarify the role of IL-27 in autoimmune diseases. Hence, this article reviewed the multiple roles of IL-27 in autoimmune diseases and describe the influence of IL-27 on the immune system.