title: Normal cellular counterparts of B cell chronic lymphocytic leukemia.
abstract: In an attempt to compare B cell chronic lymphocytic leukemia (B-CLL) with its normal cellular counterpart, the cell surface phenotype of 100 cases of B-CLL was determined by using a panel of monoclonal antibodies (MoAbs) directed against B cell-restricted and -associated antigens. The majority of B-CLL cells expressed Ia, B4 (CD19), B1 (CD20), B2 (CD21), surface immunoglobulin (sIg), and T1 (CD5) but lacked C3b (CD35) receptors. In contrast, the overwhelming majority of small unstimulated B cells expressed Ia, B4, B1, B2, sIg, and C3b receptors but lacked detectable T1. Small numbers of weakly sIg+ cells could be identified in peripheral blood and tonsil that coexpressed the B1 and T1 antigens. Approximately 16% of fetal splenocytes coexpressed B1, T1, weak sIg, B2, and Ia but lacked C3b receptors and therefore closely resembled most B-CLL cells. With the phenotypic differences between the majority of small unstimulated B cells and B-CLL cells, we examined normal in vitro activated B cells and B-CLL cells for the expression of B cell-restricted and -associated activation antigens. Of 20 cases examined, virtually all expressed B5, and approximately 50% of the cases expressed interleukin-2 receptors (IL-2R) and Blast-1. Normal B cells were activated with either anti-Ig or 12-0-tetradecanoylphorbol-beta-acetate (TPA) and then were examined for coexpression of B1, T1, and the B cell activation antigens B5 and IL-2R. Only cells activated with TPA coexpressed B1 and T1 as well as B5 and IL-2R. B cells activated with either anti-Ig or TPA proliferated in the presence of IL-2, whereas B-CLL cells did not, although they all expressed the identical 60-kilodalton proteins by immunoprecipitation. These studies are consistent with the notion that B-CLL resembles several minor subpopulations of normal B cells including a population of B cells that are activated in vitro directly through the protein kinase C pathway.
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology; D000951:Antigens, Neoplasm / Q000032:analysis; D001402:B-Lymphocytes / Q000145:classification / Q000187:drug effects / Q000276:immunology; D002469:Cell Separation; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007945:Leukemia, Lymphoid / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation; D008221:Lymphoid Tissue / Q000276:immunology; D010641:Phenotype; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000951:Antigens, Neoplasm; D007376:Interleukin-2; D011994:Recombinant Proteins; D013755:Tetradecanoylphorbol Acetate