猪瘟病毒感染对猪外周血T淋巴细胞亚群及TNF-α和IFN-γ的影响

Effect of classical swine fever virus infection on the T lymphocyte subpopulations in peripheral blood and changes of alpha-interferon and gamma-interferon of pigs

为探讨猪瘟病毒(CSFV)弱毒株T株和野毒株G株感染对猪外周血T淋巴细胞亚群、TNF-α和IFN-γ的影响,本研究应用流式细胞术和ELISA等方法检测CSFV感染猪与未感染猪的白细胞凋亡、CD4+与CD8+T淋巴细胞亚群数量的动态变化以及TNF-α和IFN-γ的动态变化。结果表明,猪感染CSFV T株和G株第4 d和第7 d后CD4+T淋巴细胞比例分别为28.6%、26%和26%、20%,未感染前分别为33.4%和36.8%。猪感染CSFV T株和G株第4 d、第7 d后CD8+T淋巴细胞比例分别为41%、32%和38%、25%,感染前分别为43.8%和48.8%。外周血白细胞凋亡的检测结果显示,猪感染CSFV T株和G株第7 d后,白细胞凋亡比例分别为8.35%和9.89%,未感染的猪为1.63%。ELISA检测结果表明,猪感染CSFV T株和G株第7 d后,TNF-α的产生量分别为553.4 pg/mL和594.2 pg/mL;IFN-γ的产生量分别为8.2 pg/mL和9.8 pg/mL,未感染猪分别为498 pg/mL、12.5 pg/mL。以上结果提示,CSFV感染会引起机体免疫相关细胞及免疫分子发生改变,这可能是导致机体发生免疫抑制的原因。

To elucidate the effects of classical swine fever virus（CSFV） low virulent strain Thiverval（T） and virulent strain GXW-07（G） infection on immune cells,kinetics of CD4＋ and CD8＋ T lymphocyte subpopulations and peripheral blood leukocytes apoptosis of pigs infected experimentally with CSFV were analyzed by flow cytometry.The results showed that CD4＋ T lymphocyte subpopulations in pigs inoculated with T or G strain was significantly decreased form 33.4% to 26% and 36.8 % to 20%,and CD8＋ T lymphocyte subpopulations was declined from 43.8% to 32% and 48.8% to 25% at 7 days post-infection（pi）,respectively.Counts of leukocyte apoptosis in peripheral blood of the infected pigs were significantly more than those of the control pigs,the IFN-γ secretion was lower than control pigs.On the contrary,the TNF-α secretion was higher than control pigs.Indicating that apoptosis induced by CSFV infection might be the cause of leucopenia and immune suppression.