高致病性猪繁殖与呼吸综合征 GD强弱毒株感染对猪外周血淋巴细胞亚群的影响

Study on Changes of Lymphocyte Subpopulations in Peripheral Blood of the PigsInoculated with Highly Pathogenic PRRSV GD Wild and Vaccine Strain

关键词:  高致病性猪繁殖与呼吸综合征  疫苗株 野毒株  感染猪 外周血淋巴细胞亚群

Key words:  highly pathogenic porcine reproductive and respiratory syndrome, vaccine strain, virulent strain  infected pigs, changes of the lymphocyte subpopulations in peripheral blood

摘要:

为了从细胞水平探讨PRRSV GD 强弱毒和PRRSV弱毒疫苗感染对外周血淋巴细胞亚群的影响,运用血常规技术和流式细胞技术分析了PRRSV感染SPF猪后,猪体内外周血淋巴细胞亚群变化。试验将30日龄20头SPF猪分成3组,1组感染HP-PRRSVGD第5代强毒株,1组感染GDr180弱毒疫苗株,1组留作对照。与感染后第0、3、7、10、14、21、28、35天采血做外周血淋巴细胞亚群测定,分析淋巴细胞亚群的变化。结果表明： HP-PRRSV GD强毒株感染可导致白细胞、淋巴细胞数量、单核细胞、粒细胞、B细胞、Tc细胞、Th细胞、Tm细胞、和γδT细胞数量的下降；而弱毒疫苗GDr180株免疫则表现为白细胞、淋巴细胞、单核细胞、引起粒细胞、B细胞、Tc细胞、Th细胞和Tm细胞的上升,对γδT细胞的影响不大；阴性对照组在整个检测期间各种细胞基本上保持稳定状态。从实验结果可以看出：与HP-PRRSVGD强毒株破坏免疫细胞不同,PRRSV弱毒疫苗 GDr180株免疫接种能刺激猪免疫细胞增殖,给试验猪提供良好的免疫反应。

Abstract:

High pathogenic porcine reproductive and respiratory syndrome (HP-PRRS),the causative agent of which is HP-PRRSV, is considered to be one of the most important infectious diseases causing severe respiratory distress in piglets and respiratory disease in pigs of all ages. PRRS, one of the OIE listed diseases has caused enormous economic losses in porcine industry, and Chinese government defined it as a B disease. The vaccine of pathogenic HP-PRRSV GD is successfully developed and it will play an important role in the prevention and control of HP-PRRSV in China. But there were few reports about the immune mechanism of the HP-PRRSV. In the study, We used an immunofluorescence assay to investigate changes in lymphocyte subpopulations in Peripheral blood of the SPF pigs inoculated with HP-PRRSV GD wild and vaccine strains, which was in a cellular way to discuss the effect between the lymphocyte subpopulations in Peripheral blood of the SPF pigs and highly pathogenic PRRSV GD wild and vaccine type. Specific-pathogen-free pigs inoculated with PRRS wild virus showed remarkable decreases in total lymphocytes,white blood cells,monocytes,granulocytes,B cells,Tc cells,Th cells, Tm cells and γδT cells, while specific-pathogen-free pigs inoculated with PRRS vaccine virus increases in total lymphocytes,white blood cells,monocytes,granulocytes,B cells、Tc cells, Th cells、Tm cells after PID 3, and the numbers of all cells remain substantially stable in the negative control group. From these results we can conclude that HP-PRRSV GD wild type can destroy immune cells, while HP-PRRSV GD wild type can stimulate immune cell proliferation, provides a good immune response to the pigs.