title: Requirement for both IL-12 and IFN-gamma signaling pathways in optimal IFN-gamma production by human T cells.
abstract: Phytohemagglutinin (PHA)-derived T lymphoblasts or T cell clones from patients genetically deficient in IL-12R beta 1 (IL-12R beta 1(-/-)) or IFN-gamma R1 (IFN-gamma R1(-/-)) produced two- to threefold reduced IFN-gamma levels compared to the corresponding cells from healthy individuals after anti-CD3 and PMA stimulation. Moderate IFN-gamma production was observed in PHA-derived T lymphoblasts or T cell clones derived from healthy subjects in the presence of anti-IFN-gamma R1 or anti-IL-12 mAb, whereas it was negligible in the presence of both mAb. However, when anti-IFN-gamma R1 and/or anti-IL-12 mAb were added during restimulation, the cells produced normal levels of IFN-gamma, indicating that both IFN-gamma and IL-12 had an effect on the priming phase. Moderate production of IFN-gamma was partially enhanced only in IFN-gamma R1(-/-) T cell clones generated in the presence of IL-12, but was almost completely abolished when IL-12R beta 1(-/-) and IFN-gamma R1(-/-) T cell clones were generated in the presence of anti-IFN-gamma R1 or anti-IL-12 mAb, respectively. IL-4 production was enhanced in T cell clones from IL-12R beta 1(-/-),but not from IFN-gamma R1(-/-) patients, whereas IL-10 and IL-2 production did not differ significantly in polyclonal T cells or clones from healthy and deficient individuals. These results indicate that IL-12R beta 1- and IFN-gamma R1-dependent signals co-ordinately regulate IFN-gamma, but not IL-2 and IL-10 production, whereas only IL-12 negatively controls IL-4 production by in vitro-generated T cell clones. Thus, although IL-12 and IFN-gamma signals are each sufficient for moderate production of IFN-gamma by human T cells, both are needed for optimal IFN-gamma production, and in the absence of both IFN-gamma production is completely abrogated.
authors.affiliation: Department of Clinical and Biological Sciences, University of Turin, Orbassano, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Losana
authors.forename: Laura
authors.initials: L
authors.lastname: Rigamonti
authors.forename: Igor
authors.initials: I
authors.lastname: Borghi
authors.forename: Barbara
authors.initials: B
authors.lastname: Assenzio
authors.forename: Silvia
authors.initials: S
authors.lastname: Ariotti
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Jouanguy
authors.forename: Frederic
authors.initials: F
authors.lastname: Altare
authors.forename: Guido
authors.initials: G
authors.lastname: Forni
authors.forename: Jean-Laurent
authors.initials: JL
authors.lastname: Casanova
authors.forename: Francesco
authors.initials: F
authors.lastname: Novelli
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002478:Cells, Cultured; D002999:Clone Cells / Q000187:drug effects / Q000378:metabolism; D018389:Codon, Nonsense; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology*; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics; D018664:Interleukin-12 / Q000235:genetics / Q000276:immunology / Q000494:pharmacology / Q000502:physiology*; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D017471:Receptors, Interferon / Q000172:deficiency / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018123:Receptors, Interleukin / Q000172:deficiency / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D053707:Receptors, Interleukin-12; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D011994:Recombinant Proteins; D017384:Sequence Deletion; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000096743:Interferon gamma Receptor
chemical_list: D000911:Antibodies, Monoclonal; D018389:Codon, Nonsense; D007371:Interferon-gamma; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D010835:Phytohemagglutinins; D017471:Receptors, Interferon; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D013755:Tetradecanoylphorbol Acetate; D000096743:Interferon gamma Receptor