弹性蛋白酶和跨膜丝氨酸蛋白酶2对蝙蝠SARS样冠状病毒刺突蛋白的协同激活作用
Synergistic activation of bat SARS-like coronaviruses spike protein by elastase and TMPRSS2.
作者信息
Yamamoto Yuichiro, Inoue Tetsuya, Sugiyama Naoto, Furukawa Miyu, Sato Kaoru, Onodera Taishi, Takahashi Yoshimasa, Wakita Takaji, Fukasawa Masayoshi, Noguchi Kohji
机构信息
Laboratory of Molecular Targeted Therapy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 6-3-1, Niijuku, Katsushika-ku, Tokyo, 125-8585, Japan.
Research Center for Vaccine Development, National Institute of Infectious Diseases, Japan Institute for Health Security, 1-23-1, Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.
出版信息
Sci Rep. 2025 Jul 21;15(1):26469. doi: 10.1038/s41598-025-11600-y.
Although numerous sarbecoviruses have been identified in bats, but most lack the ability to infect human cells. Some barriers limit coronavirus zoonosis, including susceptibility to host proteases. Here, we investigated whether exogenous protease treatment can circumvent host restrictions in two severe acute respiratory syndrome (SARS)-related bat coronaviruses. We found that the spike proteins of RaTG13 and Khosta-2, which are sarbecoviruses obtained from horseshoe bats in China and Russia, respectively, facilitated the ACE2-mediated entry of pseudotyped viruses into VeroE6/TMPRSS2 cells following elastase treatment. In contrast, trypsin and thermolysin exhibited no effects. Elastase-enhanced infectivity correlated with increased fusogenicity driven by the cleavage of spike proteins. This process was TMPRSS2-dependent and was inhibited by nafamostat, a TMPRSS2 inhibitor. Additionally, mutation of residue 809 within the S2 subunit of the RaTG13 spike protein (S809D) impaired elastase-induced cleavage and infectivity. Hence, proteolytic processing of the spike protein serves as a restriction to RaTG13 and Khosta-2 infections, which can be overcome by elastase. This suggests that elastase secreted in inflamed tissues during viral infection may increase the zoonotic potential of sarbecoviruses by facilitating human cell entry.
尽管在蝙蝠中已鉴定出多种沙贝病毒,但大多数缺乏感染人类细胞的能力。一些障碍限制了冠状病毒的人畜共患病传播,包括对宿主蛋白酶的敏感性。在此,我们研究了外源性蛋白酶处理是否可以规避两种严重急性呼吸综合征(SARS)相关蝙蝠冠状病毒的宿主限制。我们发现,分别从中国和俄罗斯的马蹄蝠中获得的沙贝病毒RaTG13和Khosta-2的刺突蛋白,在弹性蛋白酶处理后促进了假型病毒通过ACE2介导进入VeroE6/TMPRSS2细胞。相比之下,胰蛋白酶和嗜热菌蛋白酶没有效果。弹性蛋白酶增强的感染性与刺突蛋白裂解驱动的融合性增加相关。这个过程依赖于TMPRSS2,并被TMPRSS2抑制剂那法莫司他抑制。此外,RaTG13刺突蛋白S2亚基内第809位残基的突变(S809D)损害了弹性蛋白酶诱导的裂解和感染性。因此,刺突蛋白的蛋白水解加工是对RaTG13和Khosta-2感染的一种限制,而弹性蛋白酶可以克服这种限制。这表明病毒感染期间在炎症组织中分泌的弹性蛋白酶可能通过促进进入人类细胞而增加沙贝病毒的人畜共患病传播潜力。