[Effect of muramyl dipeptide on proliferation of dendritic cells derived from children acute leukemia bone marrow in vitro]

Abstract

The aim of this study was to explore the effect of muramyl dipeptide (MDP) on proliferation of dendritic cells (DCs) from bone marrow of children with acute leukemia in vitro. The mononuclear cells were isolated from bone marrow of children with acute leukemia to induce dendritic cells. The experiment was divided into 4 groups. The control group: MNC + RPMI 1640 medium; test group 1: MNC + MDP; test group 2: MNC + rhGM-CSF + IL-4 + rhTNFα; test group 3: MNC + rhGM-CSF + IL-4 + rhTNFα + MDP. The growth of DCs was observed by inverted microscope every day; the number of DCs in different groups were counted, the immunophenotypes of DCs were detected by flow cytometry on day 8 of culture. The results indicated that a certain number of typical DCs could be detected in all experimental groups. The DC number in control and 3 test groups were (0.85 ± 0.23) x 10⁵/L, (2.31 ± 0.24) x 10⁵/L, (3.26 ± 0.37) x 10⁵/L and (4.16 ± 0.34) x 10⁵/L, respectively, among which DC number is in all 3 test groups were higher than that in control group (p < 0.01), the DC number in test group 1 was lower than that in test groups 2 and 3 (p < 0.01), while it in test group 3 was higher than that in test group 2 (p < 0.01). The percentages of HLA-DR in control, test group 1, 2 and 3 were 19.98 ± 3.74, 37.24 ± 4.32, 58.81 ± 2.08 and 77.48 ± 5.57 respectively; the percentages of CD1a and CD83 in control, test group 1, 2 and 3 were 11.46 ± 2.43, 28.71 ± 6.64, 46.92 ± 4.78 and 57.03 ± 3.07, as well as 13.05 ± 5.70, 36.32 ± 5.61, 54.95 ± 7.83 and 75.70 ± 6.67 respectively. The comparison of HLA-DR, CD1a and CD83 levels in control and test group 1, 2 showed that their results were consistent with results of DC numbers. It is concluded that MDP not only promotes the proliferation of DCs derived from bone marrow of children with acute leukemia in vitro, cooperates with rhGM-CSF, rhIL-4 and rhTNFalpha in promoting of the proliferation and maturation of DCs, while the promotive effect of MDP alone on the proliferation of DCs is not as good as its combination with cytokines.