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.
Animal cell Engineering & Technology Research Center of Gansu, Northwest University for Nationalities, No.1 Xibeixincun, Lanzhou 730030, China.
Virus Res. 2016 Jul 15;220:64-9. doi: 10.1016/j.virusres.2016.04.011. Epub 2016 Apr 16.
The deletion of residues 93-102 in non-structure protein 3A of foot-and-mouth disease virus (FMDV) is associated with the inability of FMDV to grow in bovine cells and attenuated virulence in cattle.Whereas, a previously reported FMDV strain O/HKN/21/70 harboring 93-102 deletion in 3A protein grew equally well in bovine and swine cells. This suggests that changes inFMDV genome sequence, in addition to 93-102 deletion in 3A, may also affectthe viral growth phenotype in bovine cellsduring infection and replication.However, it is nuclear that changes in which region (inside or outside of 3A region) influences FMDV growth phenotype in bovine cells.In this study, to determine the region in FMDV genomeaffecting viral growth phenotype in bovine cells, we constructed chimeric FMDVs, rvGZSB-HKN3A and rvHN-HKN3A, by introducing the 3A coding region of O/HKN/21/70 into the context of O/SEA/Mya-98 strain O/GZSB/2011 and O Cathay topotype strain O/HN/CHA/93, respectively, since O/GZSB/2011 containing full-length 3A protein replicated well in bovine and swine cells, and O/HN/CHA/93 harboring 93-102 deletion in 3A protein grew poorly in bovine cells.The chimeric virusesrvGZSB-HKN3A and rvHN-HKN3A displayed growth properties and plaque phenotypes similar to those of the parental virus rvGZSB and rv-HN in BHK-21 and primary fetal porcine kidney (FPK) cells. However, rvHN-HKN3A and rv-HN replicated poorly in primary fetal bovine kidney (FBK) cells with no visible plaques, and rvGZSB-HKN3A exhibited lower growth rate and smaller plaque size phenotypes than those of the parental virus in 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 difference present in FMDV genome sequence outside the 3A coding region also have influence on FMDV replication ability in bovine cells.
口蹄疫病毒（FMDV）非结构蛋白 3A 中 93-102 残基的缺失与 FMDV 无法在牛细胞中生长以及在牛中减毒毒力有关。然而，先前报道的 FMDV O/HKN/21/70 株在 3A 蛋白中含有 93-102 缺失，在牛和猪细胞中生长情况相同。这表明，除了 3A 中的 93-102 缺失外，FMDV 基因组序列的变化也可能影响感染和复制过程中牛细胞中的病毒生长表型。然而，关键问题是哪个区域（3A 区域内外）的变化会影响牛细胞中的 FMDV 生长表型。在这项研究中，为了确定影响牛细胞中病毒生长表型的 FMDV 基因组区域，我们通过将 O/HKN/21/70 的 3A 编码区引入 O/SEA/Mya-98 株 O/GZSB/2011 和 O Cathay 拓扑型株 O/HN/CHA/93 的背景中，构建了嵌合 FMDV rvGZSB-HKN3A 和 rvHN-HKN3A，因为 O/GZSB/2011 含有全长 3A 蛋白，在牛和猪细胞中复制良好，而 O/HN/CHA/93 中的 3A 蛋白缺失 93-102，在牛细胞中生长不良。嵌合病毒 rvGZSB-HKN3A 和 rvHN-HKN3A 在 BHK-21 和原代胎牛肾（FPK）细胞中的生长特性和蚀斑表型与亲本病毒 rvGZSB 和 rv-HN 相似。然而，rvHN-HKN3A 和 rv-HN 在原代牛肾（FBK）细胞中复制能力差，没有可见的蚀斑，rvGZSB-HKN3A 在 FBK 细胞中的生长速度和蚀斑大小表型低于亲本病毒，但与含有 3A 缺失的重组病毒的生长特性和蚀斑表型相似。这些结果表明，3A 编码区以外的 FMDV 基因组序列中的差异也会影响 FMDV 在牛细胞中的复制能力。
