title: Cloning and expression of murine interleukin-1 receptor antagonist in macrophages stimulated by colony-stimulating factor 1.
abstract: Colony-stimulating factor 1 (CSF-1) can act on mature macrophages to modulate their production of inflammatory cytokines. A cDNA encoding the interleukin-1 receptor antagonist (IL-1Ra) was cloned by subtractive hybridization from a CSF-1-stimulated murine macrophage cell line, sequenced, and expressed in mammalian and bacterial cells. Mouse IL-1Ra is a 22-Kd glycoprotein that is 76% identical to its human counterpart, shows considerably less similarity to IL-1 alpha and IL-1 beta, and competes with IL-1 alpha for binding to the type I IL-1 receptor normally expressed on T cells and fibroblasts. CSF-1 treatment of mouse bone marrow-derived macrophages led to a rapid and sustained increase in IL-1Ra mRNA during the G1 phase of the cell cycle as well as to increases in mRNAs encoding IL-1 alpha and IL-1 beta. Cycloheximide inhibited CSF-1-induced IL-1 alpha mRNA synthesis, but augmented IL-1 beta mRNA production and did not affect induction of IL-1Ra mRNA. No IL-1Ra mRNA was observed in CSF-1-stimulated mouse fibroblasts engineered to express CSF-1 receptors, demonstrating that its regulation depends on cell context and can be dissociated from the proliferative response. In agreement, bacterial lipopolysaccharide, a nonmitogenic activator, also induced IL-1Ra and IL-1 mRNAs in macrophages. Unlike IL-1 alpha and beta, IL-1Ra contains a signal peptide. The kinetics of its induction and its ability to gain access to the secretory compartment imply that IL-1Ra may be secreted more efficiently than IL-1, and suggest that macrophages both positively and negatively regulate the IL-1 response.
authors.affiliation: Department of Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN 38105.
authors.forename: H
authors.initials: H
authors.lastname: Matsushime
authors.forename: M F
authors.initials: MF
authors.lastname: Roussel
authors.forename: K
authors.initials: K
authors.lastname: Matsushima
authors.forename: A
authors.initials: A
authors.lastname: Hishinuma
authors.forename: C J
authors.initials: CJ
authors.lastname: Sherr
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002460:Cell Line; D003001:Cloning, Molecular / Q000379:methods; D003513:Cycloheximide / Q000494:pharmacology; D015870:Gene Expression; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D011971:Receptors, Immunologic / Q000378:metabolism; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins / Q000096:biosynthesis; D012795:Sialoglycoproteins
chemical_list: C507763:IL1RN protein, human; C507764:Il1rn protein, mouse; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D008070:Lipopolysaccharides; D011506:Proteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; D016173:Macrophage Colony-Stimulating Factor; D003513:Cycloheximide