鉴定高致病性猪繁殖与呼吸综合征病毒弱毒疫苗株（HuN4-F112）nsp2 蛋白的非必需区域，用于在 Marc-145 细胞中的复制。

Identification of nonessential regions of the nsp2 protein of an attenuated vaccine strain (HuN4-F112) of highly pathogenic porcine reproductive and respiratory syndrome virus for replication in marc-145 cell.

机构信息

Division of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue Road, Minhang District, Shanghai 200241, China.

出版信息

Virol J. 2012 Aug 2;9:141. doi: 10.1186/1743-422X-9-141.

BACKGROUND

The regions in the middle of nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (PRRSV) have been shown to be nonessential for PRRSV replication, and these nonessential regions are different in various viral strains.

FINDING

In this study, the nonessential regions of the nsp2 of an attenuated vaccine strain (HuN4-F112) of highly pathogenic porcine reproductive and respiratory syndrome virus were identified based on an infectious cDNA clone of HuN4-F112. The results demonstrated that the segments of nsp2 [amino acids (aa) 480 to 667] tolerated deletions. Characterization of the mutants demonstrated that those with small deletions did not affect the viral growth on Marc-145 cells, but deletion of these regions led to earlier PRRSV replication increased (before 36 h after infectious in vitro).

CONCLUSION

The functional roles of nsp2 variable middle region for PRRSV HuN4-F112 replication have been identified. Our results also suggested that none-essential region might be an ideal insertion region to express foreign gene in PRRSV genome.

背景

已表明猪繁殖与呼吸综合征病毒（PRRSV）非结构蛋白 2（nsp2）的中部区域对于 PRRSV 复制并非必需，并且这些非必需区域在不同病毒株中存在差异。

发现

在这项研究中，基于高致病性猪繁殖与呼吸综合征病毒减毒疫苗株（HuN4-F112）的感染性 cDNA 克隆，鉴定了 HuN4-F112 的 nsp2 的非必需区域。结果表明，nsp2 的片段（氨基酸 480 至 667）可耐受缺失。对突变体的特征分析表明，那些具有小缺失的突变体并不影响 Marc-145 细胞上的病毒生长，但缺失这些区域会导致 PRRSV 复制更早增加（在体外感染后 36 小时之前）。