膀胱癌患者一氧化氮对外周血树突状细胞的影响

Effects of nitric oxide on peripheral blood dendritic cells in patients with bladder cancer

目的:观察外源性一氧化氮(n itric oxide,NO)对膀胱癌患者外周血树突状细胞(dendritic cell,DC)的影响.方法:膀胱癌患者外周血中分离出单个核细胞,用粒/巨噬细胞集落刺激因子(GM-CSF)、白细胞介素-4(IL-4)、肿瘤坏死因子(TNF)-α和肿瘤相关抗原(tumor assoc iated antigen,TAA)培养DC细胞.外源性NO干预后DC刺激自体淋巴细胞的增殖和细胞毒性T细胞(CTL)对膀胱癌T-24的杀伤效应,用MTT法检测.结果:外源性NO可明显抑制DC刺激的自体淋巴细胞增殖,在NO浓度分别为50,100,200和400nmol/L时淋巴细胞增殖率分别为(67±3)%,(40±6)%,(24±2)%和(18±3)%(与对照相比P<0.01);显著下调DC诱导CTL杀伤T-24的细胞毒作用,用相同的NO浓度梯度干预,杀伤率分别为(45±4)%,(38±3)%,(32±3)%和(22±1)%(与对照相比P<0.01).未受干预的DC能显著引起淋巴细胞的增殖,增殖率为(74±6)%;无NO干预DC诱导的CTL能特异性杀伤膀胱癌T-24,杀伤率为(54±3)%.结论:外源性一氧化氮能引起膀胱癌患者DC递呈抗原能力的下降,下调由DC刺激的淋巴细胞增殖及DC诱导的CTL杀瘤效应.

AIM： To investigate the effects of nitric oxide （NO） on peripheral blood dendritic cells （DCs） in patients with bladder cancer. METHODS： DCs were obtained from peripheral blood mononuclear cells （PBMC） in patients with bladder cancer. The DCs were cultured in the presence of granulocyte/macrophage colony stimulating factor （ 1 × 10^6 U/L）, interleukin-4 （5 × 10^5 U/L）, tumor necrosis factor-α （10^5 U/L） and tumor-associated antigen （TAA） extracted from human bladder cancer cell line T-24. The phenotypes （CDla, CD80, CD86 and HLA-DR） were determined by flow cytometry. The proliferation of lymphocytes induced by DCs and the cytotoxicity of cytotoxic T lymphocytes （CTL） were assayed in the presence of NO. Bladder cancer cell line T-24 was cultured as target cells and the cytotoxicity of CTL was determined by MTT assay. RESULTS： The proliferation of lymphocytes induced by DCs was inhibited by NO in a dose-dependent manner （ P 〈0.01 ）. The NO resulted in an inhibition of the cytotoxicity of CTL against bladder cancer cell line T-24 （ P〈0.01 ）. The DC in vitro induced by TAA effectively resulted in the proliferation of lymphocytes [ proliferation rate： （ 74 ± 6） % ] and the killing effect was significant on the bladder cancer cell line T-24 by CTL [ killing rate： （54 ± 3） % ]. CONCLUSION： NO can inhibit the proliferation and the activation of lymphocytes induced by DCs and down-regulate the antitumor cytotoxicity of CTL in patients with bladder cancer.