南湖新聞網(wǎng)訊(通訊員 沈洲)近日,學(xué)院彭貴青教授團(tuán)隊(duì)聯(lián)合中國(guó)農(nóng)業(yè)科學(xué)院上海獸醫(yī)研究所陳鴻軍教授團(tuán)隊(duì)研究成果“African swine fever virus I73R is a critical virulence-related gene: A potential target for attenuation”在線(xiàn)發(fā)表于國(guó)際學(xué)術(shù)期刊Proceedings of the National Academy of Sciences。研究發(fā)現(xiàn),缺失I73R基因的重組病毒完全喪失對(duì)家豬的致病性,且能抵抗致死劑量親本強(qiáng)毒株的攻擊,表明I73R是ASFV編碼的主要毒力基因之一。
2021年,本團(tuán)隊(duì)聯(lián)合中國(guó)農(nóng)業(yè)科學(xué)院上海獸醫(yī)研究所探究了抑制宿主蛋白合成的非洲豬瘟基因,闡明E66L是通過(guò)跨膜區(qū)(13-34 aa)調(diào)控PKR/eIF2α通路來(lái)抑制宿主蛋白的翻譯(Journal of Virology, 2021)。最新的合作研究成果又揭開(kāi)了ASFV一層新的面紗:I73R基因在A(yíng)SFV感染早期定位在細(xì)胞核中,發(fā)揮核酸結(jié)合特性,阻止宿主高GC成分的mRNA出核,從而廣泛抑制宿主抗病毒蛋白的合成。體內(nèi)致病性研究顯示,缺失I73R基因的重組病毒具有良好的生物安全性和免疫有效性。上述研究結(jié)果為深入理解非洲豬瘟病毒致病性和免疫逃逸機(jī)制提供了新的理論基礎(chǔ),為非洲豬瘟缺失疫苗的研發(fā)提供了新的思路。
African swine fever virus (ASFV) is a large, double-stranded DNA virus that causes a fatal disease in pigs, posing a threat to the global pig industry. Whereas some ASFV proteins have been found to play important roles in ASFV-host interaction, the functional roles of many proteins are still largely unknown. In this study, we identified I73R, an early viral gene in the replication cycle of ASFV, as a key virulence factor. Our findings demonstrate that pI73R suppresses the host innate immune response by broadly inhibiting the synthesis of host proteins, including antiviral proteins. Crystallization and structural characterization results suggest that pI73R is a nucleic-acid-binding protein containing a Zα domain. It localizes in the nucleus and inhibits host protein synthesis by suppressing the nuclear export of cellular messenger RNA (mRNAs). While pI73R promotes viral replication, the deletion of the gene showed that it is a nonessential gene for virus replication. In vivo safety and immunogenicity evaluation results demonstrate that the deletion mutant ASFV-GZΔI73R is completely nonpathogenic and provides effective protection to pigs against wild-type ASFV. These results reveal I73R as a virulence-related gene critical for ASFV pathogenesis and suggest that it is a potential target for virus attenuation. Accordingly, the deletion mutant ASFV-GZΔI73R can be a potent live-attenuated vaccine candidate