title: Macrophages and stromal cells phagocytose apoptotic bone marrow-derived B lineage cells.
abstract: It has been hypothesized that B cell precursors that undergo programmed cell death due to nonproductive Ig gene rearrangements are cleared from the bone marrow by macrophages. However, a role for macrophages in this process is supported only by micrographs showing their association with apoptotic-appearing, B lineage cells. Functional data demonstrating phagocytosis of apoptotic, bone marrow lymphocytes by macrophages have not been presented, nor have receptors potentially involved in that process been identified. The data in this report demonstrate that macrophages isolated from murine bone marrow efficiently phagocytose apoptotic murine B lineage cells using multiple receptors that include CD14, integrins, class A scavenger receptor, and CD31 (PECAM-1). In addition, the results further reveal a new role for the hemopoietic microenvironment in B cell development in view of data demonstrating that murine bone marrow stromal cells are also capable of clearing apoptotic cells via an integrin-dependent mechanism.
authors.affiliation: Department of Pathology and Laboratory Medicine and the Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Dogusan
authors.forename: Encarnacion
authors.initials: E
authors.lastname: Montecino-Rodriguez
authors.forename: Kenneth
authors.initials: K
authors.lastname: Dorshkind
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D018955:CD36 Antigens / Q000378:metabolism / Q000502:physiology; D019070:Cell Lineage / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D016023:Integrins / Q000378:metabolism / Q000502:physiology; D018950:Lipopolysaccharide Receptors / Q000378:metabolism / Q000502:physiology; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010587:Phagocytosis / Q000276:immunology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis; D051117:Scavenger Receptors, Class A; D017154:Stromal Cells / Q000166:cytology / Q000276:immunology
chemical_list: D018955:CD36 Antigens; D016023:Integrins; D018950:Lipopolysaccharide Receptors; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D051117:Scavenger Receptors, Class A