血管内皮生长因子对CD34+干/祖细胞来源的树突细胞分化及功能的影响

目的　探讨血管内皮生长因子 (VEGF)对人脐血CD34 干 /祖细胞来源的树突细胞(dendriticcell,DC)分化和功能的影响。方法　利用免疫磁珠分离法 (MACS)分离纯化脐血CD34 造血干 /祖细胞 ,并在体外将其诱导扩增为DC ,观察VEGF在培养早期和晚期对DC分化和功能的影响。观察培养过程中细胞增殖方式 ,用流式细胞术检测DC表面分化相关抗原CD1α、CD83、CD80、CD5 4、HLA DR等的表达 ,混合淋巴细胞反应法测定DC体外刺激同种异体T细胞增殖的能力 ,ELISA法检测DC培养上清中IL 12的含量。结果　在细胞增殖方面 ,培养第 1天加入VEGF(2 5ng/ml)可显著促进细胞增殖 ,第 14天收获的总细胞数量较对照组增高 (1.5 1± 0 .2 3)倍 (P =0 .0 0 1) ,而培养第 9天加入VEGF则未出现明显的促细胞增殖效应 (P >0 .0 5 ) ;在细胞分化和功能方面 ,培养第 1天加入VEGF明显抑制DC的分化和功能 ,第 1天加VEGF组和对照组DC分化抗原的表达CD1a分别为(33.0 0± 2 .12 ) %和 (81.2 0± 6 .93) % ,CD83分别为 (42 .2 3± 1.15 ) %和 (87.98± 9.79) % ,CD80分别为 (42 .93± 1.32 ) %和 (94 .5 3± 0 .87) % ,HLA DR分别为 (37.93± 5 .30 ) %和 (74 .15± 3.74 ) % (P值均 <0 .0 0 1) ,同时CD14的表达较对照组明显升高 ;刺激同种异体T淋巴

Effects of vascular endothelial growth factor on differentiation and function of dendritic cells generated from CD34+ hematopoietic progenitor cells in vitro

OBJECTIVE: To investigate the effects of vascular endothelial growth factor (VEGF) on differentiation and function of dendritic cells derived from CD34+ hematopoietic progenitor cells. METHODS: After isolation from umbilical cord blood with a high-gradient magnetic cell sorting system (MACS), the CD34+ cells were cultured with a cocktail cytokines for differentiating into dendritic cells (DC). The cells were stimulated by VEGF (25 ng/ml) either at the beginning or at day 9 of culture. Kinetics analysis of cell proliferation was performed during the process of cell culture, and the expression of DC differentiation antigens including CD1alpha, CD83, CD80, CD54 and HLA-DR was examined by flow cytometry. DC function was evaluated by the ability to induce proliferation of allogeneic T cells in mixed lymphocyte reaction (MLR) assay, and the production of IL-12 by ELISA. RESULTS: VEGF added at day 1 of culture induced an increase of total cell numbers by (1.51 +/- 0.23)-folds (P = 0.001). VEGF added at the initial but not the late stage of culture could dramatically down-regulate the expression of CD1a (33.00 +/- 2.12)% vs (81.20 +/- 6.93)%], CD83 (42.23 +/- 1.15)% vs (87.98 +/- 7.97)%], CD80 (42.93 +/- 1.32)% vs (94.53 +/- 0.87)%], and HLA-DR (37.93 +/- 5.30)% vs (74.15 +/- 3.74)%], while obviously up-regulate the expression of CD14. Moreover, the inhibitory effect of VEGF on DC function was confirmed by a reduced ability to induce proliferation of allogeneic T cells and production of IL-12 (P < 0.01). CONCLUSIONS: VEGF could induce the expansion of hematopoietic progenitor cells and inhibit at the early stage their differentiation into mature DC.