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 cells in the co-infected group were extremely significantly higher than those in the separately infected group(P<0.001).In this study,a model of co-infection of iPAMs with highly pathogenic PRRSV Li11 and SS2 strong virulent strain HA or non-virulent strain T1/5 was established for the first time,based on which it was found for the first time that PRRSV infection not only promotes adhesion,invasion,and survival of different virulent SS to and within iPAMs cells,but also significantly increases cytokine transcription.This study provides a theoretical basis for further investigation of the mechanism of mixed PRRSV and SS infection.
作者
宋冬
全映颖
高树基
申娅敏
高梦霞
王瑜欣
魏颖
汪洋
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)
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
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)。
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
porcine reproductive and respiratory syndrome virus
Streptococcus suis
immortalized porcine alveolar macrophages
co-infection
