中文摘要：

选用5头猪圆环病毒2型（PCV2）及猪呼吸和繁殖综合征病毒（PRRSV）抗体阴性普通断奶仔猪,无菌分离脾脏淋巴细胞和巨噬细胞（macrophage,M）,分别以PCV2和PCV2＋M与淋巴细胞相互作用,同时设M和淋巴细胞对照组。培养0、6、12、24 h后分别收取各组淋巴细胞,用流式细胞术对细胞凋亡率进行测定,半定量RT-PCR法测定淋巴细胞Fas和FasLmRNA的转录情况。结果显示：PCV2＋M组的淋巴细胞凋亡率在24 h时显著高于其他3组（P〈0.05）。PCV2＋M组的淋巴细胞6 h时FasmRNA转录量显著高于空白对照组（P〈0.05）,24 h时显著高于其他3组（P〈0.05）。FasLmRNA的转录变化与FasmRNA基本一致。相关性分析表明,淋巴细胞凋亡率和Fas（FasL）mRNA的转录呈极显著相关（Fas：P=0.000,r=0.606;FasL：P=0.000,r=0.579）。表明：巨噬细胞能介导PCV2诱导体外培养淋巴细胞的凋亡,这种细胞凋亡的发生与Fas/FasL系统紧密相关。

英文摘要：

Five conventional piglets with free of antibodies against porcine circovirus type 2（PCV2）and porcine reproductive and respiratory syndrome virus（PRRSV）were used for splenocytes collection.Lymphocytes and macrophages（M）isolated from spleen were distributed into four groups：lymphocytes control,co-culture with M with or without PCV2 inoculation（M＋PCV2 or M group）,and PCV2 inoculation only.The apoptosis of lymphocytes was measured with flow cytometry（FCM）at 0,6,12 and 24 h post-inoculation（HPI）,and Fas and Fas ligand（FasL）mRNA in the lymphocytes were evaluated by semiquantitative RT-PCR at the same time.The apoptotic rate in M＋PCV2 group was significantly higher than other groups at 24 h HPI（P0.05）.The expression of Fas mRNA in M＋PCV2 group was significantly elevated at 6 h（P0.05,compared with lymphocytes control）and was the highest among four groups at 24 h HPI.The expression of FasL in lymphocytes was the same as that of Fas.The relationship between apoptotic rate and expression of Fas and FasL mRNA was significantly positive correlation（apoptotic rate and Fas：P=0.000,r=0.606;apoptotic rate and FasL：P=0.000,r=0.579）.The results demonstrated that macrophages could mediate the surface expression of Fas/FasL on lymphocytes and increase lymphocytes apoptosis induced by PCV2 in vitro.