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

Area of Science:

• Virology
• Immunology
• Biotechnology

Background:

• Influenza virus causes significant global morbidity and mortality.
• Current influenza vaccines require annual updates due to viral evolution.
• Emerging drug resistance necessitates alternative therapeutic strategies.

Purpose of the Study:

• To discover single-chain variable fragments (scFvs) targeting the conserved M2 protein of influenza A virus.
• To evaluate the neutralizing activity of M2-specific antibodies against influenza virus replication.

Main Methods:

• Bio-panning of yeast surface-displayed M2 protein to isolate scFv and single-domain VL candidates.
• Recombinant protein expression and purification in E. coli.
• In vitro characterization including binding affinity, plaque reduction assays, and immunocytochemistry.

Main Results:

• Isolated several M2-specific scFv and single-domain VL antibodies with high yield and purity.
• A single-domain VL antibody (NVLM10) showed high affinity for influenza virions.
• Engineered bivalent NVL2M10 demonstrated enhanced inhibition of virus replication, reducing plaque numbers and viral protein/genome expression.

Conclusions:

• Mono- and bivalent single-domain VL antibodies targeting the M2 protein exhibit potent neutralizing activity against influenza A virus.
• These antibodies represent a potential strategy for developing universal influenza vaccines.