title: Rheumatoid factor secretion from human Leu-1+ B cells.
abstract: A human B cell subpopulation identifiable by the expression of the cell surface antigen Leu-1 (CD5) is responsible for most of the immunoglobulin M rheumatoid factor secreted in vitro after the cells are stimulated with Staphylococcus aureus. The ability of B cells bearing the Leu-1 marker (Leu-1+) to secrete rheumatoid factor is present early in development and extends to adulthood, since Leu-1+ B cells from cord blood and from peripheral blood lymphocytes of both normal adults and patients with certain autoimmune conditions secrete rheumatoid factor in comparable amounts. The neonatal enrichment of Leu-1+ B cells, the presence of Leu-1+ B cells in increased frequencies in patients with autoimmune disease, and the involvement of Leu-1+ B cells in autoantibody secretion suggest both developmental and functional homologies between this human B cell subpopulation and the murine Ly-1 B cell subpopulation.
mesh_terms: D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D001402:B-Lymphocytes / Q000145:classification* / Q000276:immunology; D002469:Cell Separation; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D007958:Leukocyte Count; D051379:Mice; D012217:Rheumatoid Factor / Q000378:metabolism*
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D007075:Immunoglobulin M; D012217:Rheumatoid Factor