Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA.
Division of Animal Science & National Swine Resource and Research Center, College of Agriculture Food and Natural Resources, University of Missouri, Columbia, MO, USA.
Emerg Microbes Infect. 2024 Dec;13(1):2387449. doi: 10.1080/22221751.2024.2387449. Epub 2024 Aug 24.
Proteolytic activation of the haemagglutinin (HA) glycoprotein by host cellular proteases is pivotal for influenza A virus (IAV) infectivity. Highly pathogenic avian influenza viruses possess the multibasic cleavage site of the HA which is cleaved by ubiquitous proteases, such as furin; in contrast, the monobasic HA motif is recognized and activated by trypsin-like proteases, such as the transmembrane serine protease 2 (TMPRSS2). Here, we aimed to determine the effects of TMPRSS2 on the replication of pandemic H1N1 and H3N2 subtype IAVs in the natural host, the pig. The use of the CRISPR/Cas 9 system led to the establishment of homozygous gene edited (GE) knockout (KO) pigs. Delayed IAV replication was demonstrated in primary respiratory cells of KO pigs . IAV infection resulted in a significant reduction of virus shedding in the upper respiratory tract, and lower virus titers and pathological lesions in the lower respiratory tract of KO pigs as compared to wild-type pigs. Our findings support the commercial use of GE pigs to mitigate influenza A virus infection in pigs, as an alternative approach to prevent zoonotic influenza A transmissions from pigs to humans.
蛋白水解酶对血凝素（HA）糖蛋白的蛋白水解激活作用对于甲型流感病毒（IAV）的感染性至关重要。高致病性禽流感病毒具有多碱性裂解位点，可被普遍存在的蛋白酶如弗林蛋白酶裂解；相比之下，单碱性 HA 基序被跨膜丝氨酸蛋白酶 2（TMPRSS2）等胰蛋白酶样蛋白酶识别和激活。在这里，我们旨在确定 TMPRSS2 对大流行性 H1N1 和 H3N2 亚型 IAV 在天然宿主猪中的复制的影响。CRISPR/Cas9 系统的使用导致了纯合基因编辑（GE）敲除（KO）猪的建立。在 KO 猪的原代呼吸道细胞中证明了 IAV 复制的延迟。与野生型猪相比，IAV 感染导致 KO 猪上呼吸道病毒脱落显著减少，下呼吸道病毒滴度和病理损伤降低。我们的研究结果支持使用 GE 猪来减轻猪中的甲型流感病毒感染，作为预防从猪到人类的人畜共患性流感 A 传播的替代方法。
