title: Cutting edge: IL-21 derived from human follicular helper T cells acts as a survival factor for secondary lymphoid organ, but not for bone marrow, plasma cells.
abstract: IL-21 induces the differentiation of activated B lymphocytes into plasma cells (PC), but its direct effect on PC remains uncertain. This study analyzes the role of IL-21 on human in vivo-generated PC. IL-21R was clearly expressed on PC from the human tonsil, the lymph node, and the spleen (secondary lymphoid organs [SLO]) but barely on terminally mature bone marrow PC. IL-21 enhanced Ig secretion by isolated SLO PC but not bone marrow PC. Tonsillar T follicular helper (Tfh) lymphocytes are known to secrete IL-21. Purified Tfh cells induced a marked increase of Ig production by tonsillar PC, and this effect was impaired when endogenous IL-21 production was blocked. IL-21 provoked a rapid and transient phosphorylation of STAT3 in tonsillar PC. Tfh cells or exogenous IL-21 reduce tonsillar PC apoptosis and increases PC recovery but does not modify their nonproliferating status. These results suggest that IL-21 derived from Tfh cells acts as a survival factor for SLO PC in vivo.
authors.affiliation: Servicio de Inmunología, Unidad de Investigación, Hospital Universitario Puerta del Mar, 11009 Cádiz, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Rodríguez-Bayona
authors.forename: Ana
authors.initials: A
authors.lastname: Ramos-Amaya
authors.forename: Jesús
authors.initials: J
authors.lastname: Bernal
authors.forename: Antonio
authors.initials: A
authors.lastname: Campos-Caro
authors.forename: José A
authors.initials: JA
authors.lastname: Brieva
mesh_terms: D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology / Q000378:metabolism; D001854:Bone Marrow Cells / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D007378:Interleukins / Q000276:immunology / Q000378:metabolism*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D053655:Receptors, Interleukin-21 / Q000276:immunology / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism; D000098546:Interleukin-21
chemical_list: D007136:Immunoglobulins; D007378:Interleukins; D053655:Receptors, Interleukin-21; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D000098546:Interleukin-21