蝙蝠SARS样冠状病毒受体识别和入侵机制研究

SARS冠状病毒是严重急性呼吸综合症病原,其囊膜蛋白（S）在病毒的入侵和跨种感染过程中起关键作用。研究证实S蛋白受体为血管紧张素转换酶II(ACE2)，其受体结合区（RBD）的关键氨基酸位点的改变可以严重影响SARS病毒与ACE2的识别和结合，从而影响病毒的感染和跨种传播。蝙蝠SARS样冠状病毒WIV1是申请人近期从菊头蝠分离到的与SARS病毒高度同源的病毒，可以高效利用人、果子狸和中华菊头蝠的ACE2。有趣的是，WIV1与SARS病毒在RBD区已知的几个关键位点存在着显著差异，推测这些位点的变异增强了WIV1利用不同物种ACE2的效率。本项目结合前期工作，利用假病毒报告系统和蛋白质相互作用技术研究和比较WIV1和SARS病毒的S蛋白利用不同物种ACE2的效率，解析影响WIV1跨种感染的关键氨基酸位点，从受体利用和入侵的角度评估WIV1的跨种感染能力和潜在的致病性。

SARS coronavirus (SARS-CoV) is the causative agent of the severe acute respiratory syndrome that outbroke in 2002-2003. The membrane spike protein (S) is responsible for the entry into cells and intersepcies infection. The SARS-CoV receptor binding domain (RBD) in S directly recognizes and binds to receptor, angiotension converting enzyme II (ACE2). The key amino acid sites in RBD play a key role in viral infection, transmission, and pathogenesis. Bat SARS-like coronavirus WIV1 (SL-CoV WIV1) was isolated from sample collected from Chinese horseshoe bat. This isolate has a higher similarity with the SARS-CoV in genomic sequence and uses ACE2s from human, civet and Chinese horseshoe bat. Interestingly, WIV1 is different from the SARS-CoV in S protein, particularly at several key amino acid residues of the RBD. We hypothesise that there are differences in receptor binding efficiency between the WIV1 and SARS-CoV S proteins with ACE2 of different origin. In this project, we will analyse and compare the ACE2 (human, civet and bat) binding efficiency between the WIV1 and SARS-CoV S protein using pseudovirus report system and protein-protein intereaction techniques. The expected results will be helpful for further understanding the interspecies infection and pathogenesis of the SL-CoV WIV1.