【摘要】 目的研究早期、晚期凋亡细胞对骨髓源性不成熟DC(imDC)的影响。方法体外以紫外线照射诱导出早期凋亡细胞;将照射后的细胞在37℃,5％CO2条件下孵育10 h,得到晚期凋亡细胞;在-70℃条件下反复冻融得到坏死细胞碎片。提取、纯化并培养骨髓源性imDC;分别以流式细胞仪、ELISA、3H-TdR掺入的混合淋巴细胞反应等方法分析imDC吞噬早期、晚期凋亡细胞或坏死细胞碎片后在表达共刺激分子、分泌IL-12 p70以及刺激T淋巴细胞增殖等方面的差异。结果imDC吞噬晚期凋亡或坏死细胞碎片后,明显趋于成熟,表现为MHCⅡ、CD40、CD80、CD86的表达均显著上调,分泌IL-12 p70增强,和T淋巴细胞混合培养后可以充分激活T淋巴细胞。而吞噬早期凋亡细胞后,仍然维持不成熟状态,表现为MHCⅡ、CD40、CD80、CD86的表达均维持于低水平,和培养中的imDC相比差异无统计学意义;分泌IL-12 p70的水平以及刺激T淋巴细胞增殖的能力均显著低于吞噬坏死细胞或晚期凋亡细胞后的DC,和培养中的imDC相比差异无统计学意义。结论早期凋亡细胞和晚期凋亡细胞的性质完全不同,晚期凋亡细胞可以充分活化抗原提呈细胞,并进一步激活T淋巴细胞,而早期凋亡细胞没有这种活化作用。更多还原

【Abstract】 Objective To study the different effects of early or late apoptotic cells on immature dendritic cells derived from bone marrow. Methods Early apoptotic spleen T cells were induced by ultraviolet irradiation for 5 minutes. imDCs were prepared from red cells and T cells depleted bone marrow cells. The imDCs were divided into five groups: group A: necrotic spleen T cells and imDC; group B: late apoptotic spleen T cells and imDC; group C: early apoptotic spleen T cells and imDC; group D: imDCs and mixture of early apoptotic and necrotic spleen T cells; group E: immature dendridic cells as negative control. Flow cytometer was employed to analyze the ratio of MHCⅡand costimulate molecule such as CD40, CD80, CD86 expressed on DCs after exposure to necrotic, late apoptotic or early apoptotic cells respectively. ELISA was employed to analyze the production of IL-12 p70 by DCs in different groups. T cells proliferation assay was employed to study DCs’ T cells stimulatory capacity. Results The DC expressed high level of MHCⅡand costimulatory molecules when exposd to necrotic cells or apoptotic cells at late stage but not early apoptotic cells. The DCs also expressed high level of MHCⅡand costimulatory molecules after exposure to mixture of early apoptotic cells and necrotic cells. Both apoptotic cells at late stage and necrotic cells increased IL-12 p70 production by DCs. Only DCs which exposed to necrotic or late apoptotic cells gain significant T lymphocytes stimulatory capacity. Conclusion Apoptotic cells at late stage have the capacity to induce the maturation of dendritic cells.更多还原