title: GP5 expression in Marc-145 cells inhibits porcine reproductive and respiratory syndrome virus infection by inducing beta interferon activity.
abstract: The major neutralizing epitope of porcine reproductive and respiratory syndrome virus (PRRSV) is mainly located on virus glycoprotein 5 (GP5). Immunization with exogenous GP5 or exposure to native GP5 by means of DNA immunization can provide some degree of immune protection to PRRSV infection in pigs. However, during PRRSV infection in pigs, the production of neutralization antibodies induced by GP5 is delayed or suppressed. This suggests that the synthesis of GP5 is late than some PRRSV proteins or other PRRSV proteins interfering with the function of GP5 in inducing host responses during virus infection. Here, to exclude the impacts of the other PRRSV proteins and determine the role of GP5 in the replication of PRRSV in vitro, a Marc-145 cell line stably expressing GP5 (Marc-145-GP5(Flag)) was constructed. Cell proliferation and cell apoptosis measurements indicated that the expression of GP5 in Marc-145 cells did not disturb the cells' viability. Following infection with different PRRSV strains PRRSV replication in Marc-145-GP5(Flag) cells was inhibited significantly. Type I interferon assay results showed that beta interferon (IFN-β) in the Marc-145-GP5(Flag) cells were increased at mRNA and protein levels. When siRNA was introduced into the cells to knock down IFN-β mRNA, PRRSV infectivity of these cells was recovered. These data suggest that early GP5 expression is not favorable for further infection by PRRSV, because it not only stimulates production of neutralization antibodies in pigs, but also induces IFN-β production in host cells. Therefore, GP5 is an important protein in the induction of self-protection responses from the host.
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: jimingao2006@163.com.
authors.forename: Jiming
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: tiankonglan246@163.com.
authors.forename: Pengchao
authors.initials: P
authors.lastname: Ji
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: maozhangdong@163.com.
authors.forename: Maodong
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: wangxiangpeng2003@126.com.
authors.forename: Xiangpeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: wangchengbao@126.com.
authors.forename: Chengbao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: shqxiaojd@hotmail.com.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: muyang@nwsuaf.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Mu
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: qinzhao_2004@sina.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: taofengdu@126.com.
authors.forename: Taofeng
authors.initials: T
authors.lastname: Du
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: yanisun_2005@sina.com.
authors.forename: Yani
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK. Electronic address: julian.hiscox@liverpool.ac.uk.
authors.forename: Julian A
authors.initials: JA
authors.lastname: Hiscox
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; College of Animal Science and Veterinary Medicine, Henan Agriculture University, Zhengzhou 450002, China. Electronic address: zhanggaiping2003@yahoo.com.cn.
authors.forename: Gaiping
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People's Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: zhouem@nwsuaf.edu.cn.
authors.forename: En-Min
authors.initials: EM
authors.lastname: Zhou
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival; D002522:Chlorocebus aethiops; D000939:Epitopes; D006023:Glycoproteins; D016899:Interferon-beta / Q000378:metabolism*; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D034741:RNA, Small Interfering; D013552:Swine; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: D000939:Epitopes; D006023:Glycoproteins; D034741:RNA, Small Interfering; D014759:Viral Envelope Proteins; C114789:glycoprotein 5, PRRSV; D016899:Interferon-beta
keywords: Cell apoptosis; Cell viability; GP5; Interferon; PRRSV