title: Association of decreased phosphorylation of ERK-2 with costimulation of rat T cell activation by MEK-1 inhibitors and TGF-beta1.
abstract: Transforming growth factor-beta (TGF-beta) is usually known as an immunosuppressive cytokine, but we and others have shown stimulatory effects of TGF-beta on activation of Th2 T-lymphocytes. In the present investigation we have studied the effect of TGF-beta1 on phosphorylation of ERK, a MAP-kinase downstream of the Ras pathway. ERK is phosphorylated by MEK-1 and PD098059 and U0126 are specific inhibitors for this kinase. We demonstrate in the present study that these inhibitors abrogate the inhibitory effect of adh-splc (adherent-spleen cells) on activation of primary rat T-cells and induce a strong costimulatory effect almost as strong as we have previously shown with TGF-beta1. When TGF-beta1 is acting stimulatory on T-cell activation, it decreases phosphorylation of ERK-2 and thereby its activation. To investigate whether TGF-beta1 and MEK-1 inhibitors influence the same pathways, we compared their effects on cytokine profiles associated with SEA-induced rat T cell activation. TGF-beta1 induced IL-10 production, slightly decreased TNF-alpha production and decreased IFN-gamma production. The PD098059 inhibitor decreased both IFN-gamma and TNF-alpha production and together with TGF-beta1, it totally blocked IFN-gamma, TNF-alpha and IL-10 production. Thus TGF-beta1 and PD098059 showed overlapping but not identical effects on the cytokine pattern.
authors.affiliation: The Wallenberg Laboratory, Department of Cell and Molecular Biology, Section of Tumor Immunology, University of Lund, Sölvegatan 21, 220 07, Lund, Sweden. asa.schiott@wblab.lu.se
authors.forename: A
authors.initials: A
authors.lastname: Schiött
authors.forename: H O
authors.initials: HO
authors.lastname: Sjögren
authors.forename: M
authors.initials: M
authors.lastname: Lindvall
mesh_terms: D000818:Animals; D002070:Butadienes / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D006224:Cricetinae; D015536:Down-Regulation; D004768:Enterotoxins / Q000494:pharmacology; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D008213:Lymphocyte Activation; D048369:MAP Kinase Kinase 1; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors*; D009570:Nitriles / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D051381:Rats; D011920:Rats, Inbred WF; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: D002070:Butadienes; D004768:Enterotoxins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D009570:Nitriles; D016212:Transforming Growth Factor beta; C113580:U 0126; C026066:enterotoxin A, Staphylococcal; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one