PT - JOURNAL ARTICLE AU - Bersudsky, Marina AU - Luski, Lotem AU - Fishman, Daniel AU - White, Rosalyn M AU - Ziv-Sokolovskaya, Nadya AU - Dotan, Shahar AU - Rider, Peleg AU - Kaplanov, Irena AU - Aychek, Tegest AU - Dinarello, Charles A AU - Apte, Ron N AU - Voronov, Elena TI - Non-redundant properties of IL-1α and IL-1β during acute colon inflammation in mice AID - 10.1136/gutjnl-2012-303329 DP - 2014 Apr 01 TA - Gut PG - 598--609 VI - 63 IP - 4 4099 - http://gut.bmj.com/content/63/4/598.short 4100 - http://gut.bmj.com/content/63/4/598.full SO - Gut2014 Apr 01; 63 AB - Objective The differential role of the IL-1 agonists, IL-1α, which is mainly cell-associated versus IL-1β, which is mostly secreted, was studied in colon inflammation. Design Dextran sodium sulfate (DSS) colitis was induced in mice globally deficient in either IL-1α or IL-1β, and in wild-type mice, or in mice with conditional deletion of IL-1α in intestinal epithelial cells (IECs). Bone marrow transplantation experiments were performed to assess the role of IL-1α or IL-1β of myeloid versus colon non-hematopoietic cells in inflammation and repair in acute colitis. Results IL-1α released from damaged IECs acts as an alarmin by initiating and propagating colon inflammation, as IL-1α deficient mice exhibited mild disease symptoms with improved recovery. IL-1β is involved in repair of IECs and reconstitution of the epithelial barrier during the resolution of colitis; its deficiency correlates with disease exacerbation. Neutralisation of IL-1α in control mice during acute colitis led to alleviation of clinical and histological manifestations, whereas treatment with rIL-1Ra or anti-IL-1β antibodies was not effective. Repair after colitis correlated with accumulation of CD8 and regulatory T cells in damaged crypts. Conclusions The role of IL-1α and IL-1β differs in DSS-induced colitis in that IL-1α, mainly of colon epithelial cells is inflammatory, whereas IL-1β, mainly of myeloid cell origin, promotes healing and repair. Given the dissimilar functions of each IL-1 agonistic molecule, an IL-1 receptor blockade would not be as therapeutically effective as specific neutralising of IL-1α, which leaves IL-1β function intact.