title: Impaired generation of bone marrow B lymphocytes in mice deficient in C/EBPbeta.
abstract: CAAT/enhancer binding proteins (C/EBP) are a family of transcription factors that mediates adipocyte differentiation and the regulation of genes expressed in immune responses and inflammation, such as interleukin-6 (IL-6), IL-8, and granulocyte colony-stimulating factor (G-CSF). We investigated the role of C/EBPbeta (NF-IL6) in the generation of bone marrow B lymphocytes by taking advantage of C/EBPbeta-/- mice. We found that the expansion of bone marrow (BM) B lymphocytes was impaired in long-term lymphoid cultures from C/EBPbeta-/- mice. Consistent with this finding, the number of BM B cells was decreased in C/EBPbeta-/- mice. Both the levels of IL-7 gene expression and bioactive IL-7 from BM stromal cells were decreased in C/EBPbeta-/- mice. Furthermore, the proliferative responsiveness of BM B-cell precursors to IL-7 was also reduced as compared to wild-type mice, indicating that C/EBPbeta is required for the generation of BM B cells induced by IL-7. Accordingly, IL-7 stimulates the C/EBPbeta DNA-binding activity of normal BM pre-B lymphocytes as well as of 70Z/3 pre-B cells. These results point to C/EBPbeta as a critical signaling molecule in BM B lymphopoiesis.
authors.affiliation: Dipartimento di Medicina Sperimentale e Clinica, Università di Reggio Calabria, Catanzaro, Italy.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: C
authors.initials: C
authors.lastname: Ambrosino
authors.forename: M R
authors.initials: MR
authors.lastname: Ruocco
authors.forename: V
authors.initials: V
authors.lastname: Poli
authors.forename: L
authors.initials: L
authors.lastname: Romani
authors.forename: I
authors.initials: I
authors.lastname: Quinto
authors.forename: S
authors.initials: S
authors.lastname: Barbieri
authors.forename: K L
authors.initials: KL
authors.lastname: Holmes
authors.forename: S
authors.initials: S
authors.lastname: Venuta
authors.forename: G
authors.initials: G
authors.lastname: Scala
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology*; D022762:CCAAT-Enhancer-Binding Proteins; D002452:Cell Count; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005434:Flow Cytometry; D015851:Interleukin-7 / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008817:Mice, Mutant Strains; D009687:Nuclear Proteins / Q000378:metabolism*
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D015851:Interleukin-7; D009687:Nuclear Proteins