Role of JAK2 signal transductional pathway in activation and survival of human peripheral eosinophils by interferon-gamma (IFN-gamma)

The purpose of this study was to determine whether the JAK pathway is invol ved in eosinophil activation and survival through IFN-gamma receptor signal ling in human peripheral eosinophils. Eosinophils were purified from the bl ood of six atopic disease patients by anti-CD16 magnetic bead-negative sele ction. IFN-gamma significantly up-regulated survival and CD69 expression in 24-48 h cultured eosinophils. Further, IFN-gamma induced tyrosine phosphor ylation of JAK2 in eosinophils, as indicated by Western blot analysis. Fina lly, the specific JAK2 inhibitor AG-490 inhibited the tyrosine phosphorylat ion of JAK2, IFN-gamma-induced survival and CD69 expression in eosinophils. In conclusion, these results indicate that IFN-gamma induces eosinophil su rvival and CD69 expression through the activation of JAK2 in peripheral eos inophils, suggesting that JAK2 may play a significant role in eosinophil re gulation by IFN-gamma-IFN-gamma R interaction.