人巨细胞病毒体外感染诱导早幼粒细胞白血病细胞凋亡

Human Cytomegalovirus Induces Apoptosis of Human Promyelocytic Leukemic Cells via Direct Infection In Vitro

本研究探讨人巨细胞病毒(hCMV)体外感染是否可引起早幼粒细胞的增殖、分化抑制、诱导其凋亡,并探讨其作用机制。采用hCMVAD169株体外感染早幼粒细胞白血病细胞HL-60,用PCR检测hCMVDNA,用形态学观察、DNA片段化检测及AnnexinⅤ/PI染色流式细胞仪检测等方法分析细胞凋亡情况。结果表明:hCMVAD169株在体外能明显抑制早幼粒细胞白血病细胞HL-60的生长,抑制程度与病毒感染滴度呈剂量依赖关系;PCR检测发现病毒感染组HL-60细胞中有hCMVIEA的表达;形态学观察和DNA片段化检测证实了细胞凋亡的存在;流式细胞仪检测结果显示HL-60细胞凋亡率随培养液中病毒浓度的加大和感染时间的延长而增高,二者呈依赖关系。结论:hCMVAD169株在体外可直接感染HL-60细胞;hCMVAD169株在体外感染HL-60细胞后,可抑制HL-60细胞的分化和增殖;hCMVAD169株体外感染HL-60细胞后可诱导其凋亡,且凋亡率与病毒剂量及作用时间呈依赖性关系。

The study was purposed to investigate the proliferation and the suppression effect of human cytomegalovirus （hCMV） on human promyelocyte cell line HL-60, and to study whether hCMV can induce apoptosis of HL-60 via direct infection in vitro and its mechanism. Promyelocyte cell line HL-60 and hCMV AD169 strain were co-cultured. PCR was used to detect the direct infection of HL-60 cells by hCMV IEA expression. The apoptosis cells were analyzed by morphologic observation, DNA ladder formation, flow cytometry with Annexin V/PI stain. The results indicated that hCMV AD169 suppressed the differentiation and proliferation of HL-60 cells in vitro significantly （P 〈0.05 ）. The suppression was dose-dependent, hCMV DNA was successfully detected in HL-60 cells of viral infection groups by PCR. The apoptotic cells were confirmed by morphologic observation and DNA ladder formation. The results of flow cytometry showed that the percentage of apoptotic ceils increased along with the increase of hCMV titer and the time after infection. It is concluded that the promyelocyte can be infected directly by hCMV AD169 strain, hCMV AD169 strain inhibited the differentiation and proliferation of promyelocyte. The apoptosis of HL-60 cells can be induced by hCMV infection. With the increase of viral infectious titer and the time after infection,the percentage of apoptotic cells also increase and produce in dose-dependent and time- dependent manner. Induced apoptosis may be one of the mechanisms of granulocytopenia induced by hCMV infection.