2 DISTINCT ANTIGEN SYSTEMS IN HUMAN LYMPHOCYTE-B - IDENTIFICATION OF CELL-SURFACE AND INTRACELLULAR ANTIGENS USING MONOCLONAL-ANTIBODIES

  • 1 January 1984
    • journal article
    • research article
    • Vol. 58  (1) , 183-192
Abstract
Two distinct antigen systems (L26 and L27) specifically expressed in human B lymphocytes were identified using TB2-2B3 (2B3) and T3-5B3 (5B3) monoclonal antibodies, respectively. Whereas L26 antigen defined by 2B3 were rarely expressed on the surface of B cells but was abundant in the cytoplasm; L27 antigens detected by 5B3 was clearly expressed on the cell surface. These 2 antigens appeared to be restricted in their expression to B cells, as they were found in most B cells but not other cell types including thymocytes, T cells, monocytes and granulocytes. Functional studies demonstrated that L27 was more easily lost from B cells after activation with pokeweed mitogen than was L26. Likewise, plasma cell myeloma, as well as normal plasma cells, was devoid of both L26 and L27; immunoblastic sarcoma of B cell type expressed L26 but not L27. These 2 antigens co-existed in the same B cell lines including Epstein-Barr virus transformed B cell lines, B cell type acute lymphatic leukemia (B-ALL) cell line, Burkitt''s lymphoma cell lines and myeloma cell lines; but pre-B and common ALL cell lines were entirely negative for both L26 and L27. Immunoprecipitation studies showed that L26 consisted of at least 2 polypeptide chains with MW of 30 K [kilodaltons] and 33 K, which were clearly distinct from HLA-DR antigens. The antigen L27 is presently under study.