title: Inhibition of HSP70 reduces porcine reproductive and respiratory syndrome virus replication in vitro.
abstract: BACKGROUND
  Successful viral infection requires the involvement of host cellular factors in their life cycle. Heat shock protein 70 (HSP70) can be recruited by numerous viruses to promote the folding, maturation, or assembly of viral proteins. We have previously shown that HSP70 is significantly elevated in porcine reproductive and respiratory syndrome virus (PRRSV)-infected lungs, suggesting HSP70 may play a potential role during PRRSV infection. In this study, we tried to investigate the role of HSP70 during PRRSV infection.
  
  
  RESULTS
  In this study, we observed that PRRSV infection induced the expression of HSP70. The down-regulation of HSP70 using quercetin, a HSPs synthesis inhibitor, or small interfering RNAs (siRNA) reduced the viral protein level and viral production. Notably, these inhibitory effects on PRRSV infection could be attenuated by heat shock treatment. In addition, HSP70 was found to colocalize with the viral double-stranded RNA (dsRNA) and knockdown of HSP70 decreased the dsRNA levels, suggesting HSP70 is involved in the formation of viral replication and transcription complex (RTC) and thus affects the viral replication.
  
  
  CONCLUSIONS
  Our study revealed that HSP70 is an essential host factor required for the replication of PRRSV. The inhibition of HSP70 significantly reduced PRRSV replication, which may be applied as an effective antiviral strategy.
authors.forename: Jintao
authors.initials: J
authors.lastname: Gao
authors.forename: Shuqi
authors.initials: S
authors.lastname: Xiao
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.forename: Liangliang
authors.initials: L
authors.lastname: Wang
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Ji
authors.forename: Delin
authors.initials: D
authors.lastname: Mo
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, P, R, China. chyaosh@mail.sysu.edu.cn.
authors.forename: Yaosheng
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D055785:Gene Knockdown Techniques; D018840:HSP70 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D011794:Quercetin / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D013552:Swine; D014779:Virus Replication
chemical_list: D018840:HSP70 Heat-Shock Proteins; D034741:RNA, Small Interfering; D011794:Quercetin