Abstract:

BACKGROUND: Interleukin (IL)-15 is a member of hematopoietic cytokine superfamily. It may stimulate the proliferation of the myelodysplastic syndrome (MDS) hematopoietic stem/progenitor cells.
OBJECTIVE: To investigate the effects of IL-15 on proliferation of hematopoietic cells in MDS child.
METHODS: Cell-counting, MTT-inhibitory test were used to examine the inhibitory effect of IL-15 (0, 10, 20, 50, 100, 200 µg/L) on the proliferation of MDS CD34⁺ cells in 18 children aged 1-14 years to find out the peak concentration of IL-15. IL-15 at peak concentration served as experimental group, whereas those without IL-15 as control group. 12-day culture was done to understand optimal proliferation time of cells.
RESULTS AND CONCLUSION: At day 8, CD34⁺cells cultured in vitro grew well. With increased IL-15 concentration, living cells number increased as well. When IL-15 was 100 µg/L, its proliferation status was the best, but when IL-15 was 200 µg/L, its proliferation status was below the mark. At day 8, the inhibitory rate of IL-15 on CD34⁺ cells was the lowest. When IL-15’s concentration was between 0 and 100 µg/L. With increased IL-15’s concentration, the inhibition decreased progressively. When IL-15 was above 100 µg/L, the inhibition reinforced on the contrary. These indicate that IL-15 can accelerate MDS bone marrow CD34⁺ hematopoietic stem/progenitor cell proliferation in a dose-and time-dependent manner