| First Author | Berenson LS | Year | 2004 |
| Journal | Eur J Immunol | Volume | 34 |
| Issue | 9 | Pages | 2365-74 |
| PubMed ID | 15307169 | Mgi Jnum | J:91789 |
| Mgi Id | MGI:3050741 | Doi | 10.1002/eji.200324829 |
| Citation | Berenson LS, et al. (2004) Frontline: Absence of functional STAT4 activation despite detectable tyrosine phosphorylation induced by murine IFN-alpha. Eur J Immunol 34(9):2365-74 |
| abstractText | We previously reported that IL-12, but not IFN-alphaA/D, induces T helper type (Th) 1 development and STAT4 phosphorylation in murine CD4(+) T cells. However, a recent study reported that IFN-alphaA/D and recombinant murine IFN-alphaA can induce STAT4 phosphorylation, although more weakly than IL-12, largely in CD8(+) rather than CD4(+) T cells. That report did not examine Th1 development or directly demonstrate induction of IFN-gamma by IFN-alpha. To address these differences, we compared IFN-alphaA/D, murine IFN-alphaA, and IL-12 for STAT4 phosphorylation, formation of active nuclear DNA binding complexes, induction of Th1 development, and production of IFN-gamma in murine CD4(+) T cells. IFN-alphaA induced detectable STAT4 phosphorylation, although at significantly lower levels than induced by IL-12. Furthermore, in contrast to IL-12, IFN-alphaA failed to induce Th1 development or the formation of DNA binding complexes or to synergize with IL-18 for induction of IFN-gamma production. STAT1-deficient CD4(+) T cells showed increased IFN-alphaA-induced STAT4 phosphorylation but still exhibited significantly lower amounts of cytokine-induced IFN-gamma compared to IL-12. In summary, these results suggest that in contrast to IL-12, IFN-alphaA does not play a functionally significant role in meditating the STAT4-dependent induction of Th1 development or IFN-gamma production in CD4(+) T cells. |
