title: Molecular mechanisms of extracellular adenine nucleotides-mediated inhibition of human Cd4(+) T lymphocytes activation.
abstract: We have previously reported that ATPgammaS, a slowly hydrolyzed analog of ATP, inhibits the activation of human CD4(+) T lymphocytes by anti-CD3 and anti-CD28 mAb. In this report we have partially characterized the signaling mechanisms involved in this immunosuppressive effect. ATPgammaS had no inhibitory effect on CD4(+) T-cell activation induced by PMA and anti-CD28, indicating that it acts proximally to the TCR. It had no effect on the calcium rise induced by CD3/CD28 stimulation, but inhibited the phosphorylation of three kinases, ERK2, p38 MAPK and PKB, that play a key role in the activation of T cells. The receptor involved in these actions remains unidentified.
authors.affiliation: Institute of Interdisciplinary Research, School of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Xavier
authors.initials: X
authors.lastname: Duhant
authors.forename: Nathalie
authors.initials: N
authors.lastname: Suarez Gonzalez
authors.forename: Liliane
authors.initials: L
authors.lastname: Schandené
authors.forename: Michel
authors.initials: M
authors.lastname: Goldman
authors.forename: Didier
authors.initials: D
authors.lastname: Communi
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Boeynaems