Characterization of a Monoclonal Antibody that Defines an Immunoregulatory T Cell Subset for Immunoglobulin Synthesis in Humans

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 77; no. 5; pp. 2914 - 2918
• Main Authors: Haynes, Barton F., Mann, Dean L., Hemler, Martin E., Schroer, Joyce A., Shelhamer, James H., Eisenbarth, George S., Strominger, Jack L., Thomas, Charles A., Mostowski, Howard S., Fauci, Anthony S.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01.05.1980; National Acad Sciences
• Subjects: Antibodies; Antibody Formation; Antibody Specificity; Antigens; Antigens, Surface - analysis; B lymphocytes; Cell lines; Chemical suspensions; Clone Cells - immunology; Epitopes; Humans; Immunoprecipitation; Isoantibodies; Lymphocyte Cooperation; Lymphocytes; Membrane Proteins - immunology; Monoclonal antibodies; Myeloma proteins; Myeloma Proteins - immunology; Rosette Formation; T lymphocytes; T-Lymphocytes - immunology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.77.5.2914

This study characterizes a monoclonal antibody (3A1), and partially characterizes the cell surface antigen and the functional peripheral blood T cell subset that it defines. The 3A1 antigen is present on the surface of several human T cell lines (HSB-2, CEM, MOLT-4, and others) in various amounts but is absent from the T cell line YT4E and all human B cell lines tested. Immunoprecipitation of an HSB-2 extract with 3A1 yielded one specific band with a molecular weight of approximately 40,000 in the presence of reducing agent. With directly fluoresceinated 3A1 antibody, fluorescence-activated cell sorter analysis showed that 85% of peripheral blood E-rosette-positive T cells were positive for the 3A1 antigen. After E-rosette-positive cells had been separated into 3A1+and 3A1-cell suspensions, the 3A1+cells helped autologous peripheral blood B cell suspensions toward pokeweed mitogen-driven proliferation and intracytoplasmic Ig production, whereas 3A1-T cells did not. Further, addition of 3A1-cells from some but not all normal subjects to cocultures of 3A1+cells and B cells actively suppressed intracytoplasmic Ig production. However, the 3A1+T cell subset could be activated by concanavalin A to maximally suppress B cell Ig synthesis in vitro. Thus, the 3A1 antibody defines a major functional subset of peripheral blood T cells and should provide a useful marker for the study of human T cell function.