猪圆环病毒2型感染小鼠脾脏内CD4^+CD25^+调节性T细胞的动态变化

Dynamics of CD4^+CD25^+ regulatory T cell in porcine circovirus type 2 infected mice

为分析猪圆环病毒2型(PCV2)感染小鼠后脾细胞中CD4+CD25+调节性T细胞(Tregs)占CD4+T细胞比例的动态变化,探讨Tregs与PCV2感染的关系,本研究选择清洁级昆明小鼠60只,随机分成实验组和对照组,实验组腹腔接种PCV2,分别在接种后第0 d、5 d、10 d、20 d、30 d和60 d取脾脏制备单细胞悬液,用FITC-CD4和PE-CD25单克隆抗体标记Tregs,采用流式细胞仪检测Tregs占总CD4+T细胞百分比的动态变化。结果表明感染组小鼠脾细胞中Tregs百分比从第5 d开始逐步上升,第20 d达峰值后逐渐下降,感染组Tregs百分比第10 d、20 d、30 d时显著高于对照组(p<0.05),但第60 d两组间差异不显著(p>0.05)。试验结果证明PCV2感染昆明小鼠后,可在小鼠脾脏内诱导明显的Tregs增殖,这些增殖的细胞可能在PCV2感染中发挥免疫抑制作用。

To investigate the dynamics of CD4^＋CD^25＋ regulatory T cells（Tregs） in KM mice following infection by porcine circovirus type 2（PCV2） and explore the relationship between PCV2 and Tregs.Healthy KM mice were inoculated with PCV2 via the intraperitoneal route.Splenocytes were collected at 0,5,10,20,30 and 60 days post infection（dpi） and stained with the PE-conjugated CD4^＋ antibody and the FITC-conjugated CD^25＋ antibody.The proportion of Tregs in CD4^＋ T cells were measured by flow cytometry.The results showed that the Tregs increased at 5 dpi,reached the peak at 20 dpi,then decreased gradually.At 10,20 and 30 dpi,the proportion of Tregs was significantly higher than that of the control group（p0.05）,but there was no difference between the two groups at 60 dpi.This study confirmed that intraperitoneal inoculation of PCV2 could increase the proportion of Tregs in mice,which may induce immunosuppression in infected PVC2 animals.