IL11

Interleukin-11 (IL-11) is a cytokine in the interleukin-6 (IL-6) family. It is produced by various stromal and hematopoietic cells in response to inflammatory signals. IL-11 exerts its effects by binding to the IL-11 receptor alpha (IL-11Rα) in combination with the common signal-transducing subunit gp130, triggering intracellular signaling cascades such as the JAK/STAT, MAPK, and PI3K pathways.

Receptor and signaling: The IL-11–IL-11Rα complex recruits gp130, leading to activation of Janus kinases (JAK1 and JAK2, and sometimes TYK2) and phosphorylation of STAT3, which translocates to the nucleus to regulate gene expression. Negative regulation involves SOCS proteins. IL-11 signaling is widely expressed in hematopoietic and stromal tissues.

Functions: IL-11 promotes megakaryocyte maturation and platelet production, playing a role in thrombopoiesis. It also influences other hematopoietic lineages and can modulate immune responses. In tissues, IL-11 can contribute to tissue remodeling and, in some contexts, fibrosis, with studies exploring its role in models of liver, lung, and intestinal fibrosis.

Clinical relevance: Recombinant human IL-11, marketed as oprelvekin (Neumega), has been used to reduce chemotherapy-induced thrombocytopenia by stimulating megakaryopoiesis. It is administered to support platelet counts in certain cancer patients, though use is associated with side effects such as edema, fatigue, headache, and cardiovascular events, and its use follows clinical guidelines.

Research: Beyond hematopoiesis, IL-11 has been implicated in pathological fibrosis and cancer progression in preclinical studies, highlighting its diverse roles in inflammation and tissue remodeling. Its context-dependent effects remain an active area of investigation.