製備抗H7N9流感病毒非結構蛋白NS1與核蛋白NP之單鏈抗體

Abstract

根據世界衛生組織統計，截至2019年4月全球有1568個人感染新型H7N9流感病毒的確診病例，且死亡率高達40%，為了治療及預防病毒大流行，開發能有效中和病毒的抗體是當務之急。A型流感病毒之非結構性蛋白(non-structural protein 1, NS1) 能抑制受感染宿主的免疫系統，且能增加病毒感染力；而核蛋白(nucleoprotein, NP) 的主要功能為包裹病毒的染色體，進而影響病毒的轉錄、複製及病毒顆粒包裝。因此若能抑制NS1與NP之功能，應可達到抑制病毒感染之功效。本研究的主要目標是將抗H7N9 NS1及NP之單株抗體製備成單鏈抗體之形式，並在單鏈抗體之N端加上穿膜序列，再進一步確認單鏈抗體之功能及穿膜效果。未來希望此單鏈抗體可以有效降低H7N9的病毒複製及感染能力。

The novel avian-origin H7N9 influenza virus has caused 1,568 laboratory-confirmed human cases with a fatality rate approaching 40% according to WHO’s reports. It is in an urgent need for developing neutralizing antibodies for disease treatment and control. The influenza non-structural protein 1 (NS1) can inhibit host cell immune response to improve virus infection, and nucleoprotein (NP) can encapsulate the virus genome for transcription, replication and packaging. The present study aims to utilize the anti-NS1 and anti-NP antibodies for inhibiting H7N9 viral infection and replication. However, the large molecular size of the antibody is not able to directly penetrate through the membranes of the infected host cells for interacting with NS1 and NP. Therefore, the single-chain variable fragment (scFv) antibodies against H7N9 NS1 and NP have been constructed with an N-terminal penetratin peptide (PEN) for enhancing membrane permeability. In the future, the membrane permeability of the scFvs and their capability for inhibiting H7N9 virus replication and infection in MDCK cells will be further characterized.