[Function, molecular structure and gene expression of interleukin-11 (IL-11/AGIF)].

Interleukin-11 (IL-11) is a novel cytokine that was identified in a medium conditioned by the primate bone marrow-derived stromal cell line PU-34. It was originally identified as a growth factor for the IL-6-dependent plasmacytoma cell line T1165. Adipogenesis inhibitory factor (AGIF) was cloned from the human bone marrow-derived cell line KM-102. The AGIF cDNA sequence was revealed to be identical to that of the IL-11 cDNA. AGIF inhibits the process of adipogenesis of the bone marrow-derived preadipocyte cell line H-1/A. Other biological activities of IL-11/AGIF, megakaryocytopoiesis, stem-cell proliferation, hepatic acute phase responses and antigen-specific antibody responses are also summarized.