The potential role of interleukin-37 in infectious diseases.

Interleukin-37 (IL-37) is a newly introduced cytokine to interleukin-1 family. Many studies have demonstrated that IL-37 owns immunosuppressive effects against both innate and acquired immune responses via inhibition of several inflammatory mediators. Thence, IL-37 has anti-inflammatory action in some diseases including cancer, autoimmune diseases, cardiovascular diseases and infectious diseases. Recent investigations have reported the important role of IL-37 in immunity against viral, bacterial and fungal infections as they prevent inappropriate immune activation and suppress the inflammation induced by these infectious agents. Thus, IL-37 could play a crucial role in protecting host tissues from injury during infections by damping excessive inflammatory reactions. However, the precise roles of IL-37 in infectious diseases remain largely unknown. The current review shed light on the pivotal role of IL-37 in infectious diseases such as the human immunodeficiency virus-1 (HIV-1), viral myocarditis, hepatitis C virus (HCV), hepatitis B virus (HBV), tuberculosis, leprosy, pneumococcal pneumonia, listeria infection, aspergillosis, candidiasis and eumycetoma. In conclusion, this review reported that IL-37 has a crucial role in reducing infection-associated inflammation and has a good impact on inflammation-induced pathology. However, tight regulation that achieved balance between effector immune responses that required for pathogen elimination and limited tissue damage that resulted from excessive inflammation should be existed in the potential IL-37 therapy to prevent clinical complications of a disease.

Interleukin-18 (IL-18) and infectious diseases, with special emphasis on diseases induced by intracellular pathogens.

Interleukin-18 (IL-18) is a novel cytokine mainly produced by activated macrophages. IL-18 was originally called interferon-gamma inducing factor, due to its action in inducing IFN-gamma secretion from Th1 cells, NK cells and NKT cells. It has been reported that IL-18 may play important roles in various diseases including cancer and infectious diseases. This review deals with the roles of IL-18 in infectious diseases, with special emphasis on IL-18 in infectious diseases caused by intracellular pathogens including Mycobacterium tuberculosis, Mycobacterium leprae, Listeria monocytogenes and Salmonella typhimurium.