PRRSV在感染早期通过活化CREB竞争抑制p65与CBP结合  

Porcine reproductive and respiratory syndrome virus competitively inhibits the binding of p65 to CBP by activating CREB in the early stage of infection

作　　者：李先斌[1] 王鑫[1] 谭祥梅 陈鹏飞[1] 赵雄伟 吴瑕 虞凌雪[1] 高飞[1] 姜一峰[1] 于海[1] 童光志[1] 周艳君[1] LI Xian-bin;WANG Xin;TAN Xiang-mei;CHEN Peng-fei;ZHAO Xiong-wei;WU Xia;YU Ling-xue;GAO Fei;JIANG Yi-feng;YU Hai;TONG Guang-zhi;ZHOU Yan-jun(Shanghai Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Shanghai 200241,China)

机构地区：[1]中国农业科学院上海兽医研究所

出　　处：《中国预防兽医学报》2019年第7期670-676,共7页Chinese Journal of Preventive Veterinary Medicine

基　　金：国家科技支撑计划项目(2015BAD12B01-1);国家“973”计划项目(2014CB542700);国家生猪现代产业技术体系建设项目(CARS-36)

摘　　要：为研究细胞内cAMP反应元件结合蛋白(CREB)的结合蛋白(CBP)在高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)感染后的结合动态对Ⅰ型干扰素(IFN-Ⅰ)表达的影响,本研究利用HP-PRRSV强毒Hu N4株感染宿主细胞,采用CO-IP方法分析CREB的磷酸化情况及其结合动态。结果显示Hu N4株感染猪肺泡巨噬细胞(PAMs)能够引起CREB明显磷酸化,Hu N4株感染PAMs和Marc-145细胞使p38磷酸化水平显著上调,PKA通路抑制剂可以明显抑制Marc-145细胞中CREB的磷酸化水平,但不影响PAMs中CREB的磷酸化水平。并且Hu N4株感染Marc-145细胞1 h后磷酸化的CREB能够与CBP结合,并抑制了p65与CBP的结合。当抑制剂H-89和SB203580抑制Marc-145细胞中CREB的磷酸化后,CREB与CBP的结合同时受到抑制。本研究表明HP-PRRSV Hu N4株感染细胞后,可以通过激活p38 MAPK通路而活化CREB,活化的CREB与p65竞争结合CBP,而抑制p65与CBP的结合,使得HP-PRRSV在感染早期抑制了IFN-β的表达。本研究为深入研究HP-PRRSV的免疫抑制机理提供了实验依据。In order to study the effect of the binding behavior of the binding protein(CBP) of cAMP-response element binding protein(CREB) in cells on the expression of type Ⅰ interferon after infection with highly pathogenic Porcine reproductive and respiratory syndrome virus(HP-PRRSV), a HP-PRRSV virulent strain HuN4 was used to analyze the phosphorylation status and binding dynamics of CREB by CO-IP. The results showed that infection of HuN4 strain induced the upregulation of CREB phosphorylation in PAMs as well as the phosphorylation level of p38 was upregulated significantly in PAMs and Marc-145 cells.The PKA inhibitors were able to notably inhibit the phosphorylation of CREB in Marc-145 cells, but they failed to achieve this in PAMs. Moreover, one hour after HuN4 strain infection in Marc-145 cells, the phosphorylated CREB could bind to CBP, which inhibited the binding activity of CBP with p65 meanwhile. However, the binding between CREB and CBP could be inhibited as long as the phosphorylation of CREB was inhibited by inhibitors H-89 and SB203580 in Marc-145 cells. This study demonstrates that the infection of Hu N4 strain of HP-PRRSV activates CREB by the p38 MAPK-mediated pathway, which competitively binds to CBP and inhibits the binding of p65 to CBP, and thus leading to the suppression of IFN-β expression in the early stage of the viral infection. This study provides an experimental basis for further study of the immunosuppressive mechanisms of HP-PRRSV.

关 键 词：高致病性猪繁殖与呼吸综合征病毒 CREB P65 CBP IFN-Β 

分 类 号：S852.65[农业科学—基础兽医学]