IL-4 activates a distinct signal transduction cascade from IL-3 in factor-dependent myeloid cells.

摘要: Interleukin-4 (IL-4) was shown to induce a potent mitogenic response in the IL-3-dependent myeloid progenitor cell line, FDCP-2. Although IL-4 could not sustain long-term growth of FDCP-2 cells, it enhanced their serum-free medium containing IL-3. triggered prominent tyrosine phosphorylation substrate(s) migrating at 170 kDa and less striking several other proteins, including receptor. By contrast, IL-3 induced distinct proteins 145, 97, 70, 55 52 same line. treatment cells caused dramatically strong association phosphatidylinositol 3-kinase (PI 3-kinase) both with phosphorylated substrate receptor itself. only weak PI activity 97 substrate. While did affect cellular raf, stimulation shift its mobility presumably due serine/threonine phosphorylation. Taken together, our results indicate that activate cascades background; this may reflect difference biological function these two cytokines.