重型再生障碍性贫血患者树突细胞刺激异体淋巴细胞增殖的功能

目的 了解重型再生障碍性贫血(SAA)患者树突细胞(DC)刺激异体淋巴细胞增殖的功能,探讨SAA的免疫病理机制.方法 以25例SAA患者和12例正常对照者为研究对象,以重组人白介素-4(rhIL-4)、重组人粒-巨噬细胞集落刺激因子(rhGM-CSF)和重组人肿瘤坏死因子(rhTNF)体外诱导骨髓单核细胞分化为成熟髓细胞样DC(mDC),与正常淋巴细胞按1:100、1:50作混合淋巴细胞培养(MLR),噻唑兰(MTT)比色法计算淋巴细胞增殖率.ELISA法检测MLR培养上清IL-12、干扰素γ(IFNγ)浓度.分析MLR上清液IL-4、IFNγ水平与淋巴细胞增殖率相关性.结果 SAA初治组、恢复组和对照组mDC与淋巴细胞1:100混合培养时,淋巴细胞增殖率分别为(219.8 ±94.0)%、(159.1 ±66.0)%、(160.1 ±91.9)%,培养上清IL-12水平分别为(8.2±3.6)ng/L、(6.5±2.8)ng/L、(6.1±2.6)ng/L,IFNγ,水平分别为(21.8 ±8.7)ng/L、(25.5±9.1)ng/L和(22.6±7.8)ng/L3组差异均无统计学意义(P值均>0.05).初治组、恢复组和对照组mDC与淋巴细胞1:50混合培养时,淋巴细胞增殖率分别为(322.1±171.1)%、(180.9±79.1)%、(192.3 ±91.9)%,培养上清IL-12水平分别为(12.6 ±4.4)ng/L、(9.4 ±3.3)ng/L、(8.5 ±3.7)ng/L,IFNγ,水平分别为(32.3 ±9.2)ng/L、(27.4 ±6.5)ng/L、(24.4 ±7.4)ng/L,3项指标初治组均高于对照组(P<0.05),恢复组与对照组比较差异无统计学意义(P>0.05).MLR上清液IL-12水平与淋巴细胞增殖率呈正相关(r=0.529,P<0.01);MLR上清液IFNγ水平与淋巴细胞增殖率旱正相关(r=0.381,P<0.05).结论 SAA患者mDC刺激淋巴细胞增殖功能增强,在SAA发病中起重要作用.

In vitro induction of allo-T lymphocytes proliferation by myeloid dendritic cells in patients with severe aplastic anemia

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.