不同基因簇PCV2b安徽株对感染小鼠免疫应答的影响

Effects on immune responses in mice infected with different gene clusters of PCV2b Anhui strains

为探讨同一基因亚型不同基因簇的猪圆环病毒2型安徽株[PCV2-DY0801(PCV2b-1A)、PCV2-BH0801(PCV2b-1B)、PCV2-XC0801(PCV2b-1C)]对感染小鼠免疫应答的影响,将16只SPF级昆明小鼠随机分为4组,分别接种PCV2-DY0801、PCV2-BH0801、PCV2-XC0801以及PBS,初次感染后第7、14、21和28天采集血液,进行IgG水平、T细胞亚群含量及Th1型和Th2型细胞因子水平的动态检测。结果显示,3株PCV2安徽株感染小鼠后均产生较高水平的IgG,被感染小鼠的外周血中CD4+、CD8+和CD4+CD8+T淋巴细胞的含量显著减少(P<0.05),血清中IL-2、IL-4和IL-10的质量浓度显著升高(P<0.05),其中BH0801组在初次感染后第14天CD4+含量显著低于XC0801组(P<0.05),第21天IgG水平显著高于XC0801组(P<0.05),第14、21天IL-2的质量浓度显著高于XC0801组、DY0801组(P<0.05)。PCV2-BH0801诱导体液免疫反应最强,PCV2-XC0801诱导细胞免疫反应最强,而PCV2-DY0801均居中。结果表明,同一基因亚型不同基因簇的PCV2安徽株对感染小鼠的免疫应答有影响。

The objective of this study was to analyze the effect on immune responses to porcine circovirus type 2(PCV)Anhui strains[PCV2-DY0801(PCV2b-1A),PCV2-BH0801(PCV2b-1B)and PCV2-XC0801(PCV2b-1C)]in mice in the same gene subset but different gene clusters.Sixteen SPF Kunming mice were randomly allocated to four groups and were inoculated with PCV2-DY0801,PCV2-BH0801,PCV2-XC0801 and PBS,respectively.Blood samples were collected on day 7,14,21 and 28post-infection to detect the dynamic changes of IgG level,T-cell subset proportions and cytokine levels.In result,all three PCV2 Anhui strains induced high levels of IgG with a significant decrease of proportions in CD4+,CD8+,CD4+CD8+cells in peripheral blood and an obvious increase of IL-2,IL-4and IL-10 levels in serum.Specifically,CD4+proportions in the BH0801 group showed significantly lower than that of XC0801 group on day 14 postinfection.However,IgG level in the BH0801 group was dramatically higher than that of XC0801 group on day 21post-infection,and significantly higher IL-2level than XC0801 and DY0801group on day 14 and 21post-infection.PCV2-BH0801 and PCV2-XC0801 showed strongest humoral and cellular immune responses in mice,respectively,while PCV2-DY0801 only induces the mild immune response between them.The results showed that PCV2 Anhui strains in different gene clusters induced various immune responses in mice.