The cloning and biological characterization of recombinant human interleukin 11

Abstract

Interleukin 11 (IL‐11) is a pleiotropic hematopoietic growth factor with stimulatory effects on multiple hematopoietic progenitor cells. An immortalized primate bone marrow stromal cell line was established to facilitate the analysis of interactions between hematopoietic progenitors and the microenvironment. This line was found to produce a novel growth factor that directed the proliferation of a murine plasmacytoma cell line. A cDNA encoding this activity was isolated through functional expression cloning in mammalian cells. Preliminary characterization of the cytokine revealed that IL‐11 stimulated T cell‐dependent B cell immunoglobulin secretion and synergized with IL‐3 in murine megakaryocyte formation. Subsequent analysis of the clone has demonstrated that it also synergizes with IL‐3 and steel factor in the stimulation of early progenitors and affects early megakaryocyte formation and maturation. In addition, IL‐11 induces secretion of acute phase proteins in the liver and may function in the hematopoietic microenvironment as an adipogenic antagonist in a paracrine manner. Further in vitro and in vivo analysis of IL‐11 will be necessary to determine the biologic function and potential therapeutic use of the cytokine.