In vitro induction of allo-T lymphocytes proliferation by myeloid dendritic cells in patients with severe aplastic anemia / 中华内科杂志

ABSTRACT

Objective To investigate the function of myeloid dendritic cells (mDCs) from severe aplastic anemia ( SAA ) patients in stimulating allogeneic T lymphocytes proliferation in vitro and then explore the immunopathogenesis of SAA. Methods Twenty-five SAA patients ( 15 untreated and 10 recovered after immunosuppressive therapy) and 12 normal controls were enrolled in this study. Their mature mDCs were induced from their bone marrow monocytes with recombined human interleukin-4 ( rhIL-4) , recombined human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and recombined human tumor necrosis factor (rhTNF) in vitro. Then mDCs were co-cultured with allogeneic lymphocytes (mixture lymphocyte reaction, MLR) at a ratio of 1 100 or 1 50. The growth rate of lymphocyte was measured with methyl thiazolyl tetrazolium ( MTT) colorimetry.The concentrations of interleukin( IL) -12 and inlerferon -y (IFNγ) in MLR supernatant were measured with EL1SA. The correlation between the growth rate and the concentration of IL-12 or IFNγ was analyzed. Results When mDCs and lymphocytes were co-cultured at the ratio of 1 100, the growth rates of lymphocytes stimulated with mDCs from untreated, recovered SAA patients and controls were (219. 8 ±94. 0)% , (159. 1 ±66. 0)% and (160. 1 ±91. 9)% respectively. The concentrations of IL-12 in MLR supernatant were (8. 2 ± 3. 6) ng/L, (6. 5 ± 2. 8) ng/L and (6. 1 ± 2. 6) ng/L and the concentrations of IFNγ were (21. 8 ± 8. 7) ng/L, (25. 5 ± 9. 1) ng/L and (22. 6 ± 7. 8) ng/L respectively. All of them had no statistical differences among the three groups ( P > 0. 05 ). When mDCs and lymphocytes were co-cultured at the ratio of 1 50, the growth rate of lymphocytes stimulated with mDCs from untreated patients was (322. 1 ± 171. 1)% , which was higher than that of recovered patients [ (180. 9 ±79. 1)% and controls (192. 3 ±91. 9)% ]. The concentrations of IL-12 in MLR supernatant in the three groups were (12.6 ±4.4) ng/L, (9.4 ±3.3) ng/L and (8.5 ±3.7) ng/L, and the concentrations of IFNγ were (32. 3 + 9. 2 ) ng/L, ( 27. 4 ± 6. 5) ng/L and (24. 4 ± 7. 4 ) ng/L Both of the values in untreated cases were higher than those of the recovered cases or controls (P < 0. 05 ) , but there were no statistical difference between the recovered and control groups ( P >0. 05 ). The concentration of IL-12 in MLR supernatant correlated positively with the growth rate of lymphocyte (r=0. 529,P <0. 01) and so did the concentration of IFNγ (r = 0. 381, P < 0. 05). Conclusion The function of mDCs to stimulate T lymphocytes proliferation in SAA was enhanced; it might play an important role in the immunopathogenesis of SAA.