title: The Host Specificities of Baculovirus per os Infectivity Factors.
abstract: Baculoviruses are insect-specific pathogens with a generally narrow host ranges. Successful primary infection is initiated by the proper interaction of at least 8 conserved per os infectivity factors (PIFs) with the host's midgut cells, a process that remains largely a mystery. In this study, we investigated the host specificities of the four core components of the PIF complex, P74, PIF1, PIF2 and PIF3 by using Helicoverpa armigera nucleopolyhedrovirus (HearNPV) backbone. The four pifs of HearNPV were replaced by their counterparts from a group I Autographa californica multiple nucleopolyhedrovirus (AcMNPV) or a group II Spodoptera litura nucleopolyhedrovirus (SpltNPV). Transfection and infection assays showed that all the recombinant viruses were able to produce infectious budded viruses (BVs) and were lethal to H. armigera larvae via intrahaemocoelic injection. However, feeding experiments using very high concentration of occlusion bodies demonstrated that all the recombinant viruses completely lost oral infectivity except SpltNPV pif3 substituted pif3-null HearNPV (vHaBacΔpif3-Sppif3-ph). Furthermore, bioassay result showed that the median lethal concentration (LC50) value of vHaBacΔpif3-Sppif3-ph was 23-fold higher than that of the control virus vHaBacΔpif3-Hapif3-ph, indicating that SpltNPV pif3 can only partially substitute the function of HearNPV pif3. These results suggested that most of PIFs tested have strict host specificities, which may account, at least in part, for the limited host ranges of baculoviruses.
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.|Experimental Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, P. R. China.
authors.forename: Jingjiao
authors.initials: J
authors.lastname: Song
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Dianhai
authors.initials: D
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Huachao
authors.initials: H
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Xijia
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Hualin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Laboratory for Molecular Virology, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada.
authors.forename: Basil M
authors.initials: BM
authors.lastname: Arif
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Manli
authors.initials: M
authors.lastname: Wang
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000502:physiology* / Q000648:ultrastructure; D002460:Cell Line; D015967:Gene Expression Regulation, Viral; D058507:Host Specificity; D007313:Insecta / Q000821:virology*; D007814:Larva / Q000821:virology; D021381:Protein Transport; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics
chemical_list: D014764:Viral Proteins; D037521:Virulence Factors