Fig. 5

Janus kinase/signal transducer and activation of transcription (JAK/STAT) phosphorylation in granulocyte–macrophage colony-stimulating factor (GM-CSF)-stimulated neutrophils. Neutrophils were stimulated with GM-CSF (10 ng/mL) for the indicated period and lysed. Phosphorylation of JAKs, STAT3, and STAT5 was determined by Western blotting using phospho-specific antibodies against JAK2, STAT1, and STAT3. Phosphorylation of JAK1 and JAK2 was barely detected (data not shown). Three experiments were performed by using rheumatoid arthritis synovial fibroblasts isolated from three different patients with rheumatoid arthritis, and a representative result is shown