Selection and characterization of an acid-resistant mutant of serotype O foot-and-mouth disease virus
Selection and characterization of an acid-resistant mutant of serotype O foot-and-mouth disease virus
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DOI：
10.1007/s00705-013-1872-7
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发表时间：
2014-04-01
影响因子：
2.7
通讯作者：
Yu, Li
中科院分区：
文献类型：
--
作者：
Liang, Te;Yang, Decheng;Yu, Li
口蹄疫病毒（FMDV）在pH低于6.8的培养环境中由于其分解而失去感染性和免疫原性。为了研究口蹄疫病毒抗酸解的分子基础，提高口蹄疫灭活疫苗在生产过程中的酸稳定性，选择抗酸灭活的O型口蹄疫病毒突变株，并对其衣壳蛋白编码基因进行测序。在所有突变体中发现三个氨基酸取代（VP 1 N17 D、VP 2 D86 A和VP 4 S73 N）。当这些取代被单独或组合引入7个感染性FMDV克隆中时，发现VP 1蛋白中的单个氨基酸取代N17 D（其也出现在C型FMDV耐酸突变体中）负责增加O型FMDV对酸失活的抗性。此外，尽管在标准培养条件下病毒适应性降低，但在具有VP 1 N17 D取代的拯救的突变病毒rN 17 D中，病毒生长动力学和毒力没有显著改变。重要的是，与其亲本病毒0/YS/CHA/05相比，N17 D取代可以在酸性条件下赋予突变病毒rN 17 D改善的免疫原性。这些结果表明，VP 1中的N17 D取代是O型FMDV中耐酸表型的分子决定因素，表明在疫苗生产过程中使用该取代来改善灭活FMD疫苗的酸稳定性的潜力。
Foot-and-mouth disease virus (FMDV) loses infectivity and immunogenicity due to its disassembly in culture environments below pH 6.8. To study the molecular basis of viral resistance to acid-induced disassembly and improve the acid stability of inactivated FMD vaccines during the manufacturing process, type O FMDV mutants with increased resistance to acid inactivation were selected, and the genes encoding their capsid proteins were sequenced. Three amino acid substitutions (VP1 N17D, VP2 D86A, and VP4 S73N) were found in all of the mutants. When these substitutions were introduced into seven infectious FMDV clones alone or combined, a single amino acid substitution in the VP1 protein, N17D, which also appears in type C FMDV acid-resistant mutants, was found to be responsible for the increased resistance to acid inactivation for type O FMDV. In addition, although viral fitness was reduced under standard culture conditions, viral growth kinetics and virulence were not significantly altered in the rescued mutant virus rN17D with the VP1 N17D substitution. Importantly, the N17D substitution could confer improved immunogenicity to the mutant virus rN17D under acidic conditions compared with its parental virus O/YS/CHA/05. These results demonstrate that the N17D substitution in VP1 is the molecular determinant of the acid-resistant phenotype in type O FMDV, indicating the potential for use of this substitution to improve the acid stability of inactivated FMD vaccines during the vaccine production process.