Context is critical for the pivotal functions of Interleukin-6

Interleukin-6 (IL-6), once known as interferon-beta 2, has long been studied for its role in pro-inflammatory responses, notably the acute phase response and B cell maturation. However, the vastly pleiotropic functions of IL-6 have begun to be appreciated, including an anti-inflammatory role for IL-6 as a myokine in response to physical stress. To achieve such different outcomes a complex interplay is required between various cytokines, receptors and signaling pathways, much of which still requires elaboration. For instance, IL-6 can be recognized by either a surface or soluble IL-6 receptor. Evolutionary conservation of distant piscine orthologs, associations with a wide assortment of autoimmune disorders and cancers, and the availability of monoclonal antibody therapies targeting both IL-6 and IL-6R further emphasize the importance of understanding this multifunctional cytokine. more...