PRRSV诱导猪体内肺泡巨噬细胞炎症模型的建立

目的]建立猪繁殖与呼吸综合征病毒(PRRSV)诱导体内猪肺泡巨噬细胞(PAM)炎症模型,评价PRRSV感染对仔猪免疫系统的影响,为猪繁殖与呼吸综合征(PRRS)的临床诊断及科学防控提供参考依据.方法]以PRRSV-GXNN1396株人工感染30日龄健康断奶仔猪,复制出PRRS病症,剖杀后采集病料,通过组织病理学和RT-PCR检测观察各免疫器官组织的病理变化及其病毒分布情况,并检测PAM细胞内的COX-1、COX-2等酶活性变化及IL-6、IL-8、IL-10、IL-1β、IFN-γ、MCP-1和TNF-α等炎性细胞因子水平变化.结果]断奶仔猪接种PRRSV-GXNN1396株后第3d开始表现出典型的PRRS病症,PRRSV主要集中在肺脏、颌下淋巴结、血液和扁桃体等样品组织中,攻毒仔猪各主要器官的实质细胞及有关淋巴细胞均出现不同程度坏死和炎症细胞浸入现象,尤其以肺脏、肾脏、脾脏等器官受损严重,出现巨噬细胞和淋巴细胞浸润.PRRSV感染早期(第3d)仔猪PAM细胞中的ROS水平及COX-2、IL-6、IL-8、IL-10和TNF-α等因子水平均呈升高趋势,且COX-2、IL-6、IL-8和TNF-α因子水平极显著升高(P<0.01);随着感染天数的增加,PAM细胞内的COX-2、IL-6和IL-8因子水平呈下降趋势,TNF-α因子水平呈上升趋势.结论]成功建立了PRRSV诱导仔猪体内PAM细胞炎症模型,进一步佐证PRRSV主要侵害猪的免疫器官组织,以达到免疫抑制的效果,并推断感染第3d是病猪炎症反应的高峰期.

Establishment of inflammatory model of porcine alveolar macrophages induced by PRRSV

Objective]An inflammatory model of porcine pulmonary alveolar macrophages(PAM)induced by por-cine reproductive and respiratory syndrome virus(PRRSV)was established,and the impact of PRRSV infection on the immune system of piglets were evaluated to provided reference for the clinical diagnosis and prevention of porcine repro-ductive and respiratory syndrome(PRRS).Method]The 30-day-old healthy weaned piglets were artificially infected with strain PRRSV-GXNN1396 to replicate the PRRS condition.The samples were collected after the piglets were killed.The histopathological changes and distribution of virus in immune organs and tissues were observed by using histopathology and RT-PCR detection technology.Enzyme activity variation such as COX-1 and COX-2 and levels of inflammatory cyto-lines including IL-6,IL-8,IL-10,IL-1β,IFN-γ,MCP-1 and TNF-α in PAM cell were detected.Result]The results showed that the typical signs of PRRS occurred in infected weaned piglets on the 3rdday after infection of PRRSV-GXNN1396.The viruses were mainly distributed in lungs,lymph nodes,blood and tonsil.The parenchymal cells and re-lated lymphocytes in major organs of challenged piglets showed necrosis and infiltration of inflammatory cells at various degrees.In lung,kidney and spleen especially,macrophages and lymphocytes infiltrated the organs and tissues.The levels of ROS and various factors(COX-2,IL-6,IL-8,IL-10 and TNF-α)in piglets PAM cells all presented a rising trend at early PRRSV infection stage(day 3).Levels of COX-2,IL-6,IL-8 and TNF-α extremely significantly increased (P<0.01).With the increase of infection time,in PAM cell,the levels of factors such as COX-2,IL-6 and IL-8 decreased,yet TNF-α level increased.Conclusion]An inflammatory model of porcine PAM cell induced by PRRSV infection is established,which further testifies that PRRSV mainly affects the immune organs and tissues of piglets to achieve immune suppression.In addition,it is concluded that day 3 of infection is the peak of inflammatory reaction in diseased pigs.