title: Modulation of the p27kip1 cyclin-dependent kinase inhibitor expression during IL-4-mediated human B cell activation.
abstract: IL-4 activates resting B cells and, in conjunction with cosignals such as anti-IgM (anti-mu) Ab or CD40 ligand, modulates progression of B cells through the cell cycle, leading to proliferation. In this study, we show that the mitogenic combination of IL-4 and anti-mu Ab triggered induction of cyclin D3 and up-regulated cyclin-dependent kinase (cdk) 6 expression, whereas such regulation was not observed in B cells activated by IL-4 or anti-mu Ab alone. Furthermore, cyclin D3 immunoprecipitated fron as associated with cdk6, and the cyclin D3/cdk6 complex was able to phosphorylate recombinant retinoblastoma protein in vitro. In addition, B cells activated with either IL-4 or 1L-13 alone expressed a higher amount of p27kip1 (p27) cdk inhibitor than nonstimulated cells. In contrast, p27 expression was decreased when cells were activated with mitogenic combinations of IL-4 and anti-mu Ab or anti-CD40 mAb. We also observed that the IL-4-mediated inhibition of the proliferation of anti-mu/IL-2- or anti-mu/phorbol 12,13-dibutyrate-activated human leukemic B cells was associated with the maintenance of large amounts of p27 in these cells. These data suggest that IL-4 controls B cell proliferation by action during at least two steps of the regulation of the cell cycle, cyclin D3/cdk6 complex regulation and p27 inhibitor expression.
authors.affiliation: INSERM Unit 131-IPSC, Clamart, France.
authors.forename: D A
authors.initials: DA
authors.lastname: Blanchard
authors.forename: M T
authors.initials: MT
authors.lastname: Affredou
authors.forename: A
authors.initials: A
authors.lastname: Vazquez
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology*; D019013:CD40 Antigens / Q000276:immunology; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D016213:Cyclins / Q000032:analysis; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D018793:Interleukin-13 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell; D008213:Lymphocyte Activation; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D014066:Palatine Tonsil / Q000166:cytology; D010766:Phosphorylation; D016160:Retinoblastoma Protein / Q000378:metabolism; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D019013:CD40 Antigens; D018797:Cell Cycle Proteins; D016213:Cyclins; D007075:Immunoglobulin M; D018793:Interleukin-13; D008869:Microtubule-Associated Proteins; D016160:Retinoblastoma Protein; D025521:Tumor Suppressor Proteins; C044203:anti-IgM; D050760:Cyclin-Dependent Kinase Inhibitor p27; D015847:Interleukin-4; D018844:Cyclin-Dependent Kinases