title: APRIL mediates peritoneal B-1 cell homeostasis.
abstract: BLyS (B lymphocyte stimulator) family cytokines and receptors play key roles in B-2 cell maturation and survival, but their importance for B-1 cells remains less clear. Here we use knockout mice to show that APRIL (A proliferation-inducing ligand), but not BLyS, plays a role in peritoneal B-1 cell maintenance. APRIL likely exerts its effects on peritoneal B-1 cells through binding to HSPG (heparan sulfate proteoglycans) rather than to the TACI (transmembrane activator and cyclophilin ligand interactor) receptor. Finally, we show that peritoneal macrophages express high levels of APRIL message, and are a likely local source of the cytokine in this anatomic locale.
authors: Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6082, United States.
authors: Vishal J
authors: VJ
authors: Sindhava
authors: Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6082, United States.
authors: Jean L
authors: JL
authors: Scholz
authors: Division of Rheumatology, University of Southern California Keck School of Medicine, Los Angeles, CA 90033, United States.
authors: William
authors: W
authors: Stohl
authors: Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6082, United States. Electronic address: cancro@mail.med.upenn.edu.
authors: Michael P
authors: MP
authors: Cancro
mesh_terms: D000818:Animals; D053264:B-Cell Activating Factor / Q000235:genetics / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D049109:Cell Proliferation; D005786:Gene Expression Regulation; D019812:Heparan Sulfate Proteoglycans / Q000276:immunology* / Q000378:metabolism; D006706:Homeostasis / Q000235:genetics / Q000276:immunology*; D056724:Immunity, Humoral; D016130:Immunophenotyping; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D010537:Peritoneum / Q000166:cytology / Q000276:immunology; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology*; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction; D053303:Transmembrane Activator and CAML Interactor Protein / Q000235:genetics / Q000276:immunology; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000235:genetics / Q000276:immunology*
chemical_list: D053264:B-Cell Activating Factor; C120197:BLyS receptor; D019812:Heparan Sulfate Proteoglycans; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; C486361:Tnfrsf13b protein, mouse; C491959:Tnfsf13 protein, mouse; D053303:Transmembrane Activator and CAML Interactor Protein; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13
keywords: APRIL; B-1 cell; BLyS; HSPG; TACI