[Influence of cytokine combinations on proliferation and differentiation of umbilical cord blood CD34(+) cells into megakaryocytes/platelets in vitro].

In order to investigate the influence of cytokine combinations on proliferation and differentiation of human umbilical cord blood CD34(+) cells into megakaryocytes/platelets in vitro, the CD34(+) cells from human umbilical cord blood were amplified in serum-free medium StemSpan(SFEM) supplemented with several cytokine combinations by three-phase culture system. The effects of the cytokine combinations were compared. The results showed that at day 14 of the first culture phase, the CD34(+) cells cultured with cytokine combinations SCF + TPO + FL + IL-3 were amplified (11 000 ± 1 000) times, which were significantly higher than that of cells cultured with SCF + TPO + FL, but were not significantly different from that of cells cultured with SCF + TPO + IL-3 or SCF + TPO + FL + IL-3+ hydroxyl-corticosteroids. At day 7 of the second culture phase, the CD34(+) cells cultured with cytokine combination SCF + TPO + FL + IL-11 were amplified by (204666.7 ± 11718.9) times, which were significantly higher than that of cells cultured with SCF + TPO + FL + IL-3, but were not significantly different from that of cells cultured with SCF + TPO + FL + IL-11 + BMP4 + VEGF. At day 3 and day 6, the CD34(+) platelet-like cells accounted for about (39.8 ± 1.9)%, (39.7 ± 2.6)% and (25.5 ± 1.4)%, (23.1 ± 3.5)% cultured with SCF + TPO + FL + IL-11 and SCF + TPO + FL + IL-11 + BMP4 + VEGF, and significantly higher than that of the cells cultured with SCF + TPO + FL + IL-3. It is concluded that the cytokine combination of SCF + TPO + FL + IL-3 is most suitable cytokines combination for the amplification of CD34(+) hematopoietic progenitor cells. The cytokine combination of SCF + TPO + FL + IL-11 is preferred for the proliferation and differentiation of megakaryocytes, this study lays an experimental basis for investigating the proliferation and differentiation of CD34(+) into megakaryocytes/platelets in vitro.