Lu Tianyu, Song Zhiyuan, Li Qiuyan, Li Zhiguo, Wang Meng, Liu Lin, Tian Kegong, Li Ning
State Key Laboratories of Agro-biotechnology, College of Biological Science, China Agricultural University, Beijing, China.
State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center for Biotherapy, Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China.
PLoS One. 2017 Jan 4;12(1):e0169317. doi: 10.1371/journal.pone.0169317. eCollection 2017.
Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically relevant viral pathogens in pigs and causes substantial losses in the pig industry worldwide each year. At present, PRRSV vaccines do not effectively prevent and control this disease. Consequently, it is necessary to develop new antiviral strategies to compensate for the inefficacy of the available vaccines. Histone deacetylase 6 (HDAC6) is an important member of the histone deacetylase family that is responsible for regulating many important biological processes. Studies have shown that HDAC6 has anti-viral activities during the viral life cycle. However, whether HDAC6 overexpression enhances resistance to PRRSV in pigs remains unknown. In this study, we used a somatic cell cloning method to produce transgenic (TG) pigs that constitutively overexpress porcine HDAC6. These TG pigs showed germ line transmission with continued overexpression of HDAC6. In vitro, virus-challenged porcine alveolar macrophages (PAMs) overexpressed HDAC6, which suppressed viral gene expression and PRRSV production. In vivo, resistance to PRRSV in TG pigs was evaluated by direct or cohabitation mediated infection with a highly pathogenic PRRSV (HP-PRRSV) strain. Compared with non-TG (NTG) siblings, TG pigs showed a significantly lower viral load in the lungs and an extended survival time after infection with HP-PRRSV via intramuscular injection. In the cohabitation study, NTG pigs housed with challenged NTG pigs exhibited significantly worse clinical symptoms than the other three in-contact groups. These results collectively suggest that HDAC6 overexpression enhances resistance to PRRSV infection both in vitro and in vivo. Our findings suggest the potential involvement of HDAC6 in the response to PRRSV, which will facilitate the development of novel therapies for PRRSV.
猪繁殖与呼吸综合征病毒（PRRSV）是猪群中经济影响最为重大的病毒病原体之一，每年在全球养猪业造成巨大损失。目前，PRRSV疫苗无法有效防控该疾病。因此，有必要开发新的抗病毒策略来弥补现有疫苗的不足。组蛋白去乙酰化酶6（HDAC6）是组蛋白去乙酰化酶家族的重要成员，负责调控许多重要的生物学过程。研究表明，HDAC6在病毒生命周期中具有抗病毒活性。然而，HDAC6过表达是否能增强猪对PRRSV的抗性仍不清楚。在本研究中，我们采用体细胞克隆方法制备了组成性过表达猪HDAC6的转基因（TG）猪。这些TG猪表现出种系传递且HDAC6持续过表达。在体外，病毒攻击的猪肺泡巨噬细胞（PAM）中HDAC6过表达，抑制了病毒基因表达和PRRSV产生。在体内，通过高致病性PRRSV（HP-PRRSV）毒株直接感染或同居介导感染来评估TG猪对PRRSV的抗性。与非TG（NTG）同胞相比，TG猪经肌肉注射感染HP-PRRSV后，肺部病毒载量显著降低，存活时间延长。在同居研究中，与受攻击的NTG猪同栏饲养的NTG猪的临床症状明显比其他三个接触组严重。这些结果共同表明，HDAC6过表达在体外和体内均增强了对PRRSV感染的抗性。我们的研究结果表明HDAC6可能参与了对PRRSV的反应，这将有助于开发针对PRRSV的新疗法。
