title: Expression of B cell activation antigens on normal and malignant B cells.
abstract: In an attempt to relate the functional events of B cell activation with changes in cell surface molecules, we have used a panel of monoclonal antibodies directed against cell surface antigens expressed on activated but not resting B cells, to determine a sequence of activation antigen expression following anti-immunoglobulin stimulation. Within the first 24 hr of culture with anti-Ig, resting splenic B cells were induced to express B5 and interleukin-2 receptor (IL-2R) and subsequently express T9 and BB1 by 48 hr. Maximum antigen expression was seen by day 3 with the majority of cells expressing B5, IL-2R, T9, and BB1, and fewer numbers of cells expressing Blast-1 and Blast-2. By day 6, the expression of these antigens significantly decreased. Dual fluorochrome staining of anti-Ig activated B cells demonstrated heterogeneity of activation antigen expression, suggesting the existence of subpopulations of activated B cells. In an attempt to relate the non-Hodgkin's lymphomas (NHLs) to this sequence of activation, 69 tumor samples from patients with B cell NHLs were then examined for expression of these activation antigens. Histologically defined subgroups of B cell NHLs demonstrated differential expression of activation antigens with B5, BB1, and T9 exhibiting the widest distribution, whereas IL-2R, Blast-1, and Blast-2 demonstrated more limited expression. The finding that no B cell malignancy phenotypically resembles the small resting B lymphocyte coupled with the observation that virtually all B cell NHLs examined expressed activation antigens suggests that these tumors may be the neoplastic counterparts of subpopulations of activated B lymphocytes.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology*; D011971:Receptors, Immunologic / Q000276:immunology; D015375:Receptors, Interleukin-2
chemical_list: D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D000951:Antigens, Neoplasm; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2