title: Interleukin-12 enhances CD26 expression and dipeptidyl peptidase IV function on human activated lymphocytes.
abstract: Research of a cellular pathway activated by IL-12 which may result in new therapeutical approaches for IL-12, led us to find an intriguing relationship between IL-12 and CD26/DPPIV ectopeptidase on activated T cells. Both the percentage and median fluorescence intensity (MFI) of CD26+ cells in the PHA-stimulated PBMC or lymphoblasts increased when IL-12 (optimum dose, 2 ng/ml) was present. Maximum CD26 expression was observed on day-2 cultures of lymphoblasts, the presence of IL-12 receptor probably being necessary for this upregulation. In addition, CD26 upregulation correlated with enhanced DPPIV function. Enzyme affinity and secretion of the soluble form of DPPIV were not affected by IL-12. Kinetic behaviours of Ag expression and enzymatic activity support a different CD26 regulation pathway by IL-12. These data suggest that the correlation found in vivo between the CD26 expression and Th1-like immune responses is due to this IL-12-dependent upregulation.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Santiago de Compostela, Spain. bnojord@uscmail.usc.es
authors.forename: O J
authors.initials: OJ
authors.lastname: Cordero
authors.forename: F J
authors.initials: FJ
authors.lastname: Salgado
authors.forename: J E
authors.initials: JE
authors.lastname: Viñuela
authors.forename: M
authors.initials: M
authors.lastname: Nogueira
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D018819:Dipeptidyl Peptidase 4 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D004357:Drug Synergism; D004790:Enzyme Induction / Q000187:drug effects; D006801:Humans; D018664:Interleukin-12 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D018123:Receptors, Interleukin / Q000187:drug effects / Q000502:physiology; D053707:Receptors, Interleukin-12; D013601:T-Lymphocytes / Q000187:drug effects*; D018417:Th1 Cells / Q000201:enzymology* / Q000276:immunology
chemical_list: D016207:Cytokines; D010835:Phytohemagglutinins; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12; D018664:Interleukin-12; D018819:Dipeptidyl Peptidase 4