The biology of interleukin 11

Abstract

Interleukin 11 (IL‐11) is a multifunctional cytokine which may play a role in regulating the growth and development of cells in both the hematopoietic and lymphoid systems. IL‐11 activity was originally detected in the conditioned medium of a primate bone marrow stromal cell line, and the human cDNA was cloned from a human fetal lung fibroblast cell line. The purified protein shows multifunctional activity, influencing lymphohematopoietic stem cell proliferation and differentiation, megakaryocyte progenitor cell proliferation and differentiation, erythroid progenitor cell proliferation, B lymphocyte maturation, activation of hepatocyte acute phase protein synthesis, and adipogenesis. At the molecular level, IL‐11 is unique, containing no asparagine‐linked glycosylation sites and no cysteine residues. The IL‐11 receptor belongs to a family of cytokine receptors which includes the receptors for IL‐6, leukemia inhibitory factor (LIF), oncostatin M (OSM), and ciliary neurotrophic factor (CNTF), which are all capable of interacting with the signal transducing receptor gp130 after ligand binding. IL‐11 has demonstrated activity in preclinical models for the treatment of thrombocytopenia and, in some cases, neutropenia; studies are underway to confirm its usefulness in the clinic for treatment of myelosuppression associated with cancer chemotherapy and bone marrow transplantation.