【摘要】 目的:为研究猪FcγRⅢ介导猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)的免疫抑制反应。方法:本研究将含有200个TCID50的PRRSV、脂多糖(Lipopolysaccharide,LPS)(100 ng/ml)和纯化鼠抗猪FcγRⅢIgG(550μg/ml)分别处理猪肺泡巨噬细胞(Pulmonary alveolar macrophages cell,PAM),同时用纯化鼠抗猪FcγRⅢIgG处理PAM细胞后接种PRRSV,并设PAM细胞对照组。各组分别培养12、24、36、48、60、72 h后收集细胞及上清,用已经建立的绝对荧光定量PCR方法检测接毒组不同时间段的PRRSV复制水平,并用相对荧光定量PCR方法检测各组PAM细胞中IFN-α、TNF-α的mRNA转录水平。结果:PRRSV在感染PAM细胞后12~24 h期间可促进IFN-αmRNA转录水平,36~72 h期间抑制IFN-αmRNA转录水平,之后IFN-α的mRNA转录水平恢复正常;TNF-αmRNA转录水平在感染后12~72 h均略微上调。LPS处理PAM细胞后,IFN-α、TNF-αmRNA转录水平均上调。用纯化鼠抗猪FcγRⅢIgG处理猪PAM细胞后,选择性激活猪PAM细胞表面FcγRⅢ,IFN-α、TNF-αmRNA转录水平显著下调,用PRRSV感染选择性激活猪PAM细胞表面FcγRⅢ后显著抑制抗病毒因子IFN-α、TNF-αmRNA转录水平。结论:FcγRⅢ的选择性激活抑制了宿主细胞的抗病毒因子水平及在PRRSV感染过程中的天然抗病毒免疫反应。更多还原

【Abstract】 Objective: To study immunosuppression mediated by the porcine FcγRⅢ in porcine reproductive and respiratory syndrome virus( PRRSV) infection to pulmonary alveolar macrophages( PAMS). Methods: In this study pulmonary alveolar macrophages cells were treated with containing 200 TCID50 PRRSV,lipopolysaccharide( LPS)( 100 ng /ml) and purified mouse antipig FcγR Ⅲ IgG( 550 μg /ml) separately,simultaneously,PAM cells treated with purified mouse anti-pig FcγR Ⅲ IgG( 550 μg /ml)was infected by 200 TCID50 PRRSV,untreated PAM cells as the control group. Each group were post-cultured 12,24,36,48,60,72 h,the cells and the supernatant were collected. The dynamic variation of PRRSV RNA copies in inoculation group were detected by using real-time fluorescence quantitative PCR method. mRNA level of IFN-α and TNF-α in each group were detected by using relative fluorescence quantitative PCR. Results: The result showed that mRNA level of IFN-α was improved during PRRSV infection to PAMS12-24 h,and mRNA level of IFN-α was inhibited during 36-72 h,then mRNA level of IFN-α recovered normally; mRNA level of TNF-α was increased slightly post-infection 12-72 h. IFN-α and TNF-α mRNA levels of PAM cells treated with LPS were both up-regulated,using the purified mouse anti-pig FcγRⅢ IgG to treat the PAM cells,selective activation of porcine FcγRⅢ in the PAM cells down-regulated significantly mRNA levels of IFN-α and TNF-α. PRRSV infection assay mediated by selective activation FcγRⅢof the PAM cells inhibited antiviral cytokine( IFN-α and TNF-α) mRNA levels. Conclusion: The results show selective activation of FcγRⅢinhibited significantly mRNA levels of the antiviral cytokine IFN-α and TNF-α of host cells,and innate antiviral immune response to PRRSV infection.更多还原