BACKGROUND: Therapeutic targeting of Janus kinase 3 (JAK3) has received particular attention, because it is associated with the common gamma signaling of cytokine receptors and thus vitally influences T-cell growth and survival. Recent evidence, however, indicates a critical role for JAK3 in signaling linked to the T-cell antigen receptor. METHODS: In this study we investigated whether targeting JAK3 with a rationally designed inhibitor affects early T-cell activation events. T cells were stimulated by CD3 and CD28 cross-linking, and interleukin (IL)-2 production, activation marker expression, increase of free intracellular Ca2+ concentration, activation of the extracellular-related kinase, and nuclear translocation of transcription factors were evaluated. RESULTS: We found that JAK3 inhibitor treatment dramatically impaired T-cell-receptor (TCR)-induced IL-2 production, surface activation marker expression (CD69, CD154), and homotypic T-cell aggregation. Accordingly, mRNA production of IL-2, interferon-gamma, and IL-10 was profoundly inhibited. Molecular analysis revealed that TCR-triggered phosphorylation of phospholipase C-gamma1, increase in cytoplasmic Ca2+ concentration, and activation of extracellular-related kinase were markedly reduced by the JAK3 inhibitor, resulting in substantially decreased DNA binding of nuclear factor of activated T cells and alkaline phosphatase-1 and subsequent IL-2 promoter activation. Remarkably, on TCR-independent stimulation, IL-2 production, CD69 expression, and blast formation were completely insensitive to JAK3 inhibitor treatment. CONCLUSION: These data indicate that pharmacologic targeting of JAK3 uncouples early TCR-triggered signaling from essential downstream events, which may have important implications for the use of such compounds in T-cell-mediated disorders such as allograft rejection or graft-versus-host disease.

Säemann, M. D., Zeyda, M., Diakos, C., Szekeres, A., Böhmig, G. A., Kelemen, P., Parolini, O., Stockinger, H., Prieschl, E. E., Stulnig, T. M., Baumruker, T., Zlabinger, G. J., Suppression of early T-cell-receptor-triggered cellular activation by the Janus kinase 3 inhibitor WHI-P-154, <<TRANSPLANTATION>>, 2003; 75 (11): 1864-1872. [doi:10.1097/01.TP.0000065738.58742.A9] [http://hdl.handle.net/10807/92493]

Suppression of early T-cell-receptor-triggered cellular activation by the Janus kinase 3 inhibitor WHI-P-154

Parolini, Ornella;
2003

Abstract

BACKGROUND: Therapeutic targeting of Janus kinase 3 (JAK3) has received particular attention, because it is associated with the common gamma signaling of cytokine receptors and thus vitally influences T-cell growth and survival. Recent evidence, however, indicates a critical role for JAK3 in signaling linked to the T-cell antigen receptor. METHODS: In this study we investigated whether targeting JAK3 with a rationally designed inhibitor affects early T-cell activation events. T cells were stimulated by CD3 and CD28 cross-linking, and interleukin (IL)-2 production, activation marker expression, increase of free intracellular Ca2+ concentration, activation of the extracellular-related kinase, and nuclear translocation of transcription factors were evaluated. RESULTS: We found that JAK3 inhibitor treatment dramatically impaired T-cell-receptor (TCR)-induced IL-2 production, surface activation marker expression (CD69, CD154), and homotypic T-cell aggregation. Accordingly, mRNA production of IL-2, interferon-gamma, and IL-10 was profoundly inhibited. Molecular analysis revealed that TCR-triggered phosphorylation of phospholipase C-gamma1, increase in cytoplasmic Ca2+ concentration, and activation of extracellular-related kinase were markedly reduced by the JAK3 inhibitor, resulting in substantially decreased DNA binding of nuclear factor of activated T cells and alkaline phosphatase-1 and subsequent IL-2 promoter activation. Remarkably, on TCR-independent stimulation, IL-2 production, CD69 expression, and blast formation were completely insensitive to JAK3 inhibitor treatment. CONCLUSION: These data indicate that pharmacologic targeting of JAK3 uncouples early TCR-triggered signaling from essential downstream events, which may have important implications for the use of such compounds in T-cell-mediated disorders such as allograft rejection or graft-versus-host disease.
Inglese
Säemann, M. D., Zeyda, M., Diakos, C., Szekeres, A., Böhmig, G. A., Kelemen, P., Parolini, O., Stockinger, H., Prieschl, E. E., Stulnig, T. M., Baumruker, T., Zlabinger, G. J., Suppression of early T-cell-receptor-triggered cellular activation by the Janus kinase 3 inhibitor WHI-P-154, <<TRANSPLANTATION>>, 2003; 75 (11): 1864-1872. [doi:10.1097/01.TP.0000065738.58742.A9] [http://hdl.handle.net/10807/92493]
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10807/92493
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