title: Construction and characterization of 3A-epitope-tagged foot-and-mouth disease virus.
abstract: Nonstructural protein 3A of foot-and-mouth disease virus (FMDV) is a partially conserved protein of 153 amino acids (aa) in most FMDVs examined to date. Specific deletion in the FMDV 3A protein has been associated with the inability of FMDV to grow in primary bovine cells and cause disease in cattle. However, the aa residues playing key roles in these processes are poorly understood. In this study, we constructed epitope-tagged FMDVs containing an 8 aa FLAG epitope, a 9 aa haemagglutinin (HA) epitope, and a 10 aa c-Myc epitope to substitute residues 94-101, 93-101, and 93-102 of 3A protein, respectively, using a recently developed O/SEA/Mya-98 FMDV infectious cDNA clone. Immunofluorescence assay (IFA), Western blot and sequence analysis showed that the epitope-tagged viruses stably maintained and expressed the foreign epitopes even after 10 serial passages in BHK-21 cells. The epitope-tagged viruses displayed growth properties and plaque phenotypes similar to those of the parental virus in BHK-21 cells. However, the epitope-tagged viruses exhibited lower growth rates and smaller plaque size phenotypes than those of the parental virus in primary fetal bovine kidney (FBK) cells, but similar growth properties and plaque phenotypes to those of the recombinant viruses harboring 93-102 deletion in 3A. These results demonstrate that the decreased ability of FMDV to replicate in primary bovine cells was not associated with the length of 3A, and the genetic determinant thought to play key role in decreased ability to replicate in primary bovine cells could be reduced from 93-102 residues to 8 aa residues at positions 94-101 in 3A protein.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Pinghua
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Pu
authors.initials: P
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Xingwen
authors.initials: X
authors.lastname: Bai
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Huifang
authors.initials: H
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Zengjun
authors.initials: Z
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Yuanfang
authors.initials: Y
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China.
authors.forename: Yingli
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Animal Cell Engineering & Technology Research Center of Gansu, Northwest University for Nationalities, No. 1 Xibeixincun, Lanzhou 730030, China.
authors.forename: Zilin
authors.initials: Z
authors.lastname: Qiao
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Lanzhou 730046, Gansu, China. Electronic address: liuzaixin@caas.cn.
authors.forename: Zaixin
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002460:Cell Line; D000939:Epitopes / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D005536:Foot-and-Mouth Disease / Q000276:immunology / Q000821:virology*; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics* / Q000276:immunology; D015870:Gene Expression; D005818:Genetic Engineering; D016679:Genome, Viral; D008969:Molecular Sequence Data; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D010948:Viral Plaque Assay; D014779:Virus Replication
chemical_list: D000939:Epitopes; D017361:Viral Nonstructural Proteins
keywords: 3A; Foot-and-mouth disease virus; Foreign epitope