title: Influence of human T lymphocytes identified by antibodies to dipeptidyl peptidase IV on differentiation of human B lymphocytes stimulated with Staphylococcus aureus Cowan I and pokeweed mitogen.
abstract: The influence of human T lymphocytes expressing the enzyme dipeptidyl peptidase IV (DPP IV) was investigated with respect to human peripheral B-lymphocyte differentiation. B cells stimulated with pokeweed mitogen in the presence of DPP IV-positive T cells produced high amounts of immunoglobulin. Moderate amounts of immunoglobulin could be measured when B cells were cultured in the presence of DPP IV-negative T cells. DPP IV defines a T-cell subset partially overlapping the subsets characterized by the differentiation antigens Leu 3a (helper/inducer) and Leu 2a (suppressor/cytotoxic). DPP IV-positive T cells exert, in contrast to DPP IV-negative T cells, high interleukin-2 activity after stimulation with phytohemagglutinin and pokeweed mitogen. To further functionally characterize DPP IV-positive and DPP IV-negative T cells, the helper effects of Leu 3a-positive T-cell subsets, differing in DPP IV expression, were investigated in pokeweed mitogen- and Staphylococcus aureus-driven B-cell differentiation systems. After pokeweed mitogen stimulation, immunoglobulin production was markedly reduced when B cells were cultured in the presence of Leu 3a-positive T cells expressing DPP IV (DPP IV+/Leu 3a+). In contrast, high amounts of immunoglobulin were produced in cultures with Leu 3a-positive but DPP IV-negative T cells (DPP IV-/Leu 3a+). This difference in immunoglobulin production of B cells cultured with DPP IV+/Leu 3a+ and DPP IV-/Leu 3a+ T cells could not be observed in Staphylococcus aureus-stimulated cultures. Here, both T-cell subsets supported terminal differentiation of B cells. We conclude that in the pokeweed mitogen-driven culture systems, DPP IV+/Leu 3a+ and DPP IV-/Leu 3a+ T cells may differ in the production of growth and/or differentiation factors distinct from interleukin-2.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D018819:Dipeptidyl Peptidase 4; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000502:physiology*; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008211:Lymphocyte Cooperation; D010950:Plasma Cells / Q000166:cytology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000201:enzymology / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D007376:Interleukin-2; D011043:Pokeweed Mitogens; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4