title: Unraveling B-1 progenitors.
abstract: B-1 cells comprise a small percentage of the B lymphocytes that reside in multiple tissues in the mouse, including the peritoneal and pleural cavities. Functionally, B-1 cells participate in innate immunity by producing the majority of the natural IgM in serum, which protects against invading pathogens before the onset of the adaptive immune response. B-1 cells arise from fetal and neonatal progenitors and are distinct from the adult bone marrow progenitors that give rise to follicular and marginal zone B-2 cells. Recent studies have attempted to delineate the progenitors of B-1 cells from those of B-2 cells. Notably, the identification of CD45R(-/lo)CD19(+) B-1 progenitors and expression of two surface determinants, CD138 and major histocompatibility class II antigens, distinguish developing B-1 cells from B-2 cells.
authors.affiliation: Department of Genetics, Stanford School of Medicine, Stanford University, Stanford, CA 94305, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Tung
authors.forename: Leonore A
authors.initials: LA
authors.lastname: Herzenberg
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000276:immunology*; D038041:Lymphopoiesis; D051379:Mice
chemical_list: D000943:Antigens, Differentiation; D015415:Biomarkers