猪繁殖与呼吸综合征病毒促进猪链球菌2型感染猪肺泡巨噬细胞的初步研究  

A preliminary study of porcine reproductive and respiratory syndrome virus promoting Streptococcus suis type 2 infection of porcine alveolar macrophages

作　　者：宋冬 全映颖 高树基 申娅敏 高梦霞 王瑜欣 魏颖 汪洋[1,2] SONG Dong;QUAN Ying-ying;GAO Shu-ji;SHEN Ya-min;GAO Meng-xia;WANG Yu-xin;WEI Ying;WANG Yang(College of Animal Science and Technology,Henan University of Science and Technology,Luoyang 471000,China;Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry,Luoyang 471003,China)

机构地区：[1]河南科技大学动物科技学院,河南洛阳471000 [2]河南省畜禽新发传染病检测与防控工程研究中心,河南洛阳471003

出　　处：《中国预防兽医学报》2024年第4期385-391,共7页Chinese Journal of Preventive Veterinary Medicine

基　　金：国家自然科学基金项目(32172852、32302887);河南省杰出青年科学基金项目(222300420005);河南省高校科技创新团队支持计划(24IRTSTHN033)。

摘　　要：为探究猪繁殖与呼吸综合征病毒(PRRSV)对不同毒力猪链球菌2型(SS2)感染巨噬细胞的影响,本研究建立了高致病性PRRSV Li11株和SS2强毒株HA或无毒菌株T1/5共感染永生化猪肺泡巨噬细胞(iPAM)的模型,实验分为4组:HA单独感染组(HA组)、PRRSV-HA共感染组(PRRSV-HA组)、T1/5单独感染组(T1/5组)和PRRSV-T1/5共感染组(PRRSV-T1/5组),利用该模型通过黏附试验、侵入试验和细胞内存活试验检测PRRSV对HA和T1/5黏附、侵入iPAM细胞及对该细胞存活率的影响,进一步利用荧光定量PCR方法检测各感染组iPAM模型细胞中细胞因子(TNF-α、IL-6、IL-8、IFN-β)的转录水平。黏附试验结果显示,HA感染2 h后,PRRSV-HA组细菌对细胞的黏附水平极显著高于HA组(P<0.01或P<0.001);T1/5感染6 h后,PRRSV-T1/5组细菌对细胞的黏附水平极显著高于T1/5组(P<0.001),表明PRRSV与HA或T1/5共感染可以促进HA和T1/5对iPAM模型细胞的黏附,且HA对iPAM细胞的黏附水平高于T1/5。侵入试验结果显示,感染4 h后,共感染组细菌侵入iPAM细胞中的数量比单独感染组极显著增多(P<0.01或P<0.001)。细胞内存活试验结果显示,感染2 h后,共感染组细菌的存活率比单独感染组极显著升高(P<0.001)。荧光定量PCR试验结果显示,感染4 h时,共感染组iPAM细胞中细胞因子(TNF-α、IL-6、IL-8、IFN-β)的转录水平极显著高于单独感染组(P<0.001)。本研究首次建立了高致病性PRRSV Li11株和SS2强毒株HA或无毒菌株T1/5共感染i PAM的模型,基于该模型研究首次发现PRRSV感染不仅促进了不同毒力SS2对i PAM细胞的黏附、侵入及SS2在iPAM细胞内的存活,还可以协同SS2显著提高该细胞中细胞因子的转录水平。本研究为进一步探究PRRSV和SS混合感染的机制提供了参考依据。To investigate the effect of porcine reproductive and respiratory syndrome virus(PRRSV)on macrophages infected with different virulence of Streptococcus suis type 2(SS2),a model of co-infection of immortalized porcine alveolar macrophages(iPAMs)with highly pathogenic PRRSV Li11 and either a strong virulent strain of SS2,HA,or an avirulent strain,T1/5,was established in this study.The experiment was divided into the following four groups:the HA group,the PRRSV-HA group,the T1/5 group and the PRRSV-T1/5 group.The model was used to detect the effect of PRRSV on the adhesion,invasion and viability of HA and T1/5 in iPAMs cells by adhesion assay,invasion assay and intracellular survival assay,and the transcript levels of cytokines(TNF-α,IL-6,IL-8,IFN-β)were further detected by fluorescence quantitative PCR in iPAMs model cells of each infection group.The results of the adhesion assay showed that the adhesion levels of bacteria in the PRRSV-HA group were highly significant higher than those in the HA group after 2 hours of HA infection(P<0.01 or P<0.001),and the adhesion levels of bacteria in the PRRSV-T1/5 group were highly significant higher than those in the T1/5 group after 6 hours of T1/5 infection(P<0.001),indicating that the co-infection of PRRSV with HA or T1/5 can promote the adhesion of HA and T1/5 to iPAMs model cells,and the adhesion level of HA to iPAMs cells was higher than that of T1/5.The results of the invasion assay showed that after 4 hours of infection,the number of bacterial invasion into iPAMs cells in the co-infected group was highly significantly increased compared with that of the infected group alone(P<0.01 or P<0.001).The results of the intracellular survival assay showed that the survival rate of bacteria in the co-infected group was extremely significantly higher than that in the alone-infected group 2 hours after infection(P<0.001).The results of fluorescence quantitative PCR assay showed that at 4 hours of infection,the transcript levels of cytokines(TNF-α,IL-6,IL-8,and IFN-β)in iPAMs

关 键 词：猪繁殖与呼吸综合征病毒 猪链球菌 永生化猪肺泡巨噬细胞 共感染 

分 类 号：S852.6[农业科学—基础兽医学]