Akaike T, Maeda H, Maruo K, Sakata Y, Sato K
Department of Microbiology, Kumamoto University School of Medicine, Japan.
J Infect Dis. 1994 Oct;170(4):1023-6. doi: 10.1093/infdis/170.4.1023.
Common house dust mites (e.g., Dermatophagoides farinae) excrete a serine-type (Df) protease. Df protease obtained from cultured mites enhanced viral replication in vitro via proteolytic cleavage of viral hemagglutinin (HA) into HA1 and HA2, which confers potent viral infectivity. Its potency is 2- to 5-fold higher than bovine trypsin or human plasmin. Df protease also markedly accelerated virus propagation in vivo: A minute quantity of protease (estimated delivered amount, 0.8-3.2 micrograms) produced approximately 4- to 100-fold increases in infectious virus in the mouse lung. Similar augmentation of viral replication by Df protease was observed in ferret models of nasopharyngeal infections of influenza virus. All extracts from ordinary house dust contained a serine-type protease that cleaved HA into HA1 and HA2. Thus, mite protease in house dust may enhance the pathogenesis of influenza virus.
常见的屋尘螨（如粉尘螨）会分泌一种丝氨酸型（Df）蛋白酶。从培养的螨虫中获得的Df蛋白酶通过将病毒血凝素（HA）蛋白水解切割成HA1和HA2，在体外增强了病毒复制，而HA1和HA2具有强大的病毒感染力。其效力比牛胰蛋白酶或人纤溶酶高2至5倍。Df蛋白酶还显著加速了病毒在体内的传播：微量的蛋白酶（估计递送量为0.8至3.2微克）可使小鼠肺中的感染性病毒增加约4至100倍。在流感病毒鼻咽感染的雪貂模型中也观察到Df蛋白酶对病毒复制的类似增强作用。普通屋尘的所有提取物都含有一种丝氨酸型蛋白酶，可将HA切割成HA1和HA2。因此，屋尘中的螨虫蛋白酶可能会增强流感病毒的致病性。
