A cytotoxic monoclonal antibody detecting a novel B cell membrane antigen expressed predominantly on cells bearing surface membrane immunoglobulin.
A new human B lymphocyte membrane antigen, CB2, has been detected by a mouse monoclonal IgM antibody. CB2 appears to be predominantly expressed on normal and malignant cells expressing surface membrane immunoglobulin (SmIg). By indirect immunofluorescence, the number of CB2-positive cells in normal peripheral blood correlated well with the number of SmIg-positive cells. Cytotoxicity studies on isolated cell populations showed that CB2 was present on normal B cells isolated from the spleens of 52 donors and on peripheral blood B cells from 8 donors. Monocytes, T cells, granulocytes, platelets, and red cells were CB2 negative. Only malignant cells expressing SmIg were positive. These included B-CLL, B lymphoma, prolymphocytic leukemia, and B lymphoma cell lines Daudi, Raji, and Conception. SmIg-negative leukemia cells, such as common acute lymphoblastic leukemia, acute and chronic myelogenous leukemia, and T cell leukemias, were negative. Blocking studies with human immunoglobulin suggests that the CB2 antigen is not directed against immunoglobulin determinants. Immunoperoxidase studies on normal lymph node sections show that CB2-positive cells are predominantly present in the mantle region of the follicle, whereas B1-positive cells are mainly in the germinal center.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007938:Leukemia / Q000276:immunology; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009101:Multiple Myeloma / Q000276:immunology; D011233:Precipitin Tests; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D012967:Sodium Dodecyl Sulfate; D013154:Spleen / Q000166:cytology
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D011947:Receptors, Antigen, B-Cell; D012967:Sodium Dodecyl Sulfate