Journal Article

Enhancing neutralizing activity against influenza H1N1/PR8 by engineering a single-domain VL-M2 specific into a bivalent form

Ayun, Ramadhani Qurrota, Lee, Sukchan, Kim, Taehyun, Cho, Seungchan, Lee, Yongjun, Luong, Quynh Xuan Thi, Hoang, Phuong Thi, Vo, Thuy Thi Bich

2022

Overview

Flu disease, with high mortality and morbidity, is caused by the influenza virus. Influenza infections are most effectively prevented through vaccination, but it requires annual reformulation due to the antigenic shift or drift of hemagglutinin and neuraminidase proteins. Increasing resistance to available anti-influenza drugs was also recently reported. The M2 surface protein of the influenza virus is an attractive target for universal vaccine development as it is highly conserved and multifunctional throughout the viral life cycle. This study aimed to discover a single-chain variable fragment (scFv) targeting the M2 protein of influenza A H1N1/PR8, showing neutralizing activity through plaque inhibition in virus replication. Several candidates were isolated using bio-panning, including scFv and single-domain V L target M2 protein, which was displayed on the yeast surface. The scFv/V L proteins were obtained with high yield and high purity through soluble expression in E . coli BL21 (DE3) pLysE strains. A single-domain V L -M2-specific antibody, NVLM10, exhibited the highest binding affinity to influenza virions and was engineered into a bivalent format (NVL2M10) to improve antigen binding. Both antibodies inhibited virus replication in a dose-dependent manner, determined using plaque reduction- and immunocytochemistry assays. Furthermore, bivalent anti-M2 single-domain V L antibodies significantly reduced the plaque number and viral HA protein intensity as well as viral genome ( HA and NP ) compared to the monovalent single-domain V L antibodies. This suggests that mono- or bivalent single-domain V L antibodies can exhibit neutralizing activity against influenza virus A, as determined through binding to virus particle activity.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Antibodies / Antibodies, Neutralizing / Antibodies, Viral / Antigens / Binding / Biology and life sciences / Bispecific antibodies / Cloning / Cytotoxicity / Drug resistance / E coli / Escherichia coli - metabolism / Exo-a-sialidase / Genetic aspects / Genomes / HA protein / Hemagglutinin Glycoproteins, Influenza Virus - genetics / Hemagglutinins / Humans / Immunocytochemistry / Infections / Influenza / Influenza A / Influenza A Virus, H1N1 Subtype / Influenza Vaccines / Influenza viruses / Influenza, Human - prevention & control / Life cycles / Life sciences / Medicine and Health Sciences / Monoclonal antibodies / Morbidity / Neutralizing / Orthomyxoviridae Infections / Panning / Plasmids / Polyclonal antibodies / Prevention / Proteins / Public health / Replication / Research and Analysis Methods / Single-Domain Antibodies / Vaccination / Vaccine development / Vaccines / Viral infections / Viral Proteins - genetics / Virions / Viruses / Yeast / Yeasts