title: A surface membrane determinant shared by subpopulations of thymocytes and B lymphocytes.
abstract: Utilizing a quantitative fluorescence assay with the fluorescence-activated cell sorter (FACS), we have demonstrated that a rabbit antiserum obtained by immunization with cells of a mouse IgM-producing plasma cell tumor (MOPC104E) is reactive with at least two surface determinants, designated Th-B and ML2, on subpopulations of normal murine lymphocytes. The ML2 determinant is restricted to B lymphocytes. The Th-B determinant is shared by splenic B lymphocytes and a large subpopulation of thymocytes, the latter of which express a 3-fold higher density of Th-B on their surface than do the B lymphocytes. Neither Th-B nor ML2 were found on peripheral T cells or on brain, liver, or kidney cells. The available evidence suggesting that Th-B may be a stem cell determinant that is lost upon maturation is discussed.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D000961:Antilymphocyte Serum; D001402:B-Lymphocytes / Q000276:immunology*; D001665:Binding Sites; D002462:Cell Membrane / Q000276:immunology; D002469:Cell Separation; D000939:Epitopes; D005260:Female; D005455:Fluorescent Antibody Technique; D006041:Goats / Q000276:immunology; D007141:Immunoglobulin Fc Fragments; D008198:Lymph Nodes / Q000166:cytology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011817:Rabbits / Q000276:immunology; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D000936:Antigen-Antibody Complex; D000961:Antilymphocyte Serum; D000939:Epitopes; D007141:Immunoglobulin Fc Fragments