title: In vitro activation leads to the binding of T-cell markers to the surface of B-lymphocytes.
abstract: The aim of the present study was to determine whether activation of human T-cells in vitro results in the expression of markers characteristic for T-cells on the surface of B-lymphocytes and to correlate antigenic changes with the release of soluble T-cell antigens. Peripheral blood lymphocytes (PBL) were exposed in vitro to phytohemagglutinin (PHA) for 3 days. Changes in the phenotype of the cells were determined by flow cytometry and the level of soluble T-cell antigens was assessed by ELISA. PHA-activated PBL released elevated quantities of soluble CD2, CD4, and CD8 compared with control cultures. Following PHA stimulation the proportion of CD4+ CD8+ and HLA-DR+ cells increased. In addition, after 3 days of activation with PHA about 80% of the CD19+ cells (B-cells) reacted with F(ab)2 fragments of CD2 monoclonal antibodies (MoAbs). A high proportion of B-cells in activated cultures also reacted with F(ab)2 fragments of anti-CD8 MoAb and anti-CD4 MoAb. The removal of either CD4+ or CD8+ T-cells from the cultures prior to stimulations with PHA drastically reduced the proportion of B-cells expressing CD4 or CD8, respectively. The attachment of T-cell markers to the surface B-lymphocytes may constitute a new mechanism for B-cell regulation by T-cells.
authors.affiliation: Hubert H. Humphrey Center for Experimental Medicine, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Rabinowitz
authors.forename: E
authors.initials: E
authors.lastname: Massiah
authors.forename: R
authors.initials: R
authors.lastname: Hadar
authors.forename: M
authors.initials: M
authors.lastname: Schlesinger
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D000954:Antigens, Surface / Q000502:physiology*; D001402:B-Lymphocytes / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D018801:CD2 Antigens / Q000096:biosynthesis; D015704:CD4 Antigens / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D010835:Phytohemagglutinins / Q000494:pharmacology; D011485:Protein Binding / Q000502:physiology; D012995:Solubility; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D000954:Antigens, Surface; D015415:Biomarkers; D018801:CD2 Antigens; D015704:CD4 Antigens; D016827:CD8 Antigens; D010835:Phytohemagglutinins