title: Expression of 18.6/CD23 antigen on human lymphoid progenitor cell lines and phorbol 12-myristate 13-acetate (PMA)-induced microglia-shaped cells.
abstract: The nature of lymphoid progenitors and factor(s) determining commitment to either the T- or B-lymphocyte pathway are poorly understood in the human system. In this study, we generated a monoclonal antibody (MoAb), 18.6, that recognizes a cell surface antigen on a human lymphoid progenitor cell line (FL4.4). MoAb 18.6 reacted with lymphoid progenitor lines, B lymphoid cell lines, and myelomonocytic cell lines. It did not react with any T cell or erythroid leukemic cell lines. Two color FACS analyses of normal lymphoid tissues showed that MoAb 18.6 reacted with a majority of CD20+ mature B cells and a minority of CD64+ monocytes. Molecules of 3 different sizes with MW of 34, 45, and 68 Kd were precipitated with MoAb 18.6 from the lymphoid progenitor cell line. The 18.6 antigen was not expressed on a fetal liver-derived lymphoid progenitor-like cell line, FL1.4, which has the capacity to differentiate into microglia-shaped cells upon PMA-stimulation. Stimulation of FL1.4 cells with PMA induced expression of the 18.6 antigen within 24 hr and the microglia-shaped cells stained positively with MoAb 18.6. Finally, cloning of a cDNA that encoded the 18.6 antigen revealed that the 18.6 antigen is identical to the CD23 antigen. Taken together, these data suggest that the 18.6/CD23 antigen is expressed on lymphoid precursors at a very early stage of differentiation.
authors.affiliation: Department of Immunology, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Okumura
authors.forename: H
authors.initials: H
authors.lastname: Kishi
authors.forename: H
authors.initials: H
authors.lastname: Tagoh
authors.forename: J
authors.initials: J
authors.lastname: Minowada
authors.forename: A
authors.initials: A
authors.lastname: Muraguchi
mesh_terms: D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification*; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D003001:Cloning, Molecular; D005260:Female; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D017628:Microglia / Q000276:immunology; D017455:Receptors, IgE / Q000096:biosynthesis* / Q000276:immunology; D015183:Restriction Mapping; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D017455:Receptors, IgE; D013755:Tetradecanoylphorbol Acetate