A novel occludin-targeting monoclonal antibody prevents hepatitis C virus infection in vitro

Area of Science:

• Hepatology
• Virology
• Immunology

Background:

• Hepatitis C virus (HCV) entry into hepatocytes relies on host factors, making them potential therapeutic targets.
• Human occludin (hOCLN), particularly its second extracellular loop (EC2), plays a role in HCV susceptibility, but its precise function and therapeutic targeting remain unexplored.

Purpose of the Study:

• To develop and characterize a monoclonal antibody (mAb) targeting the hOCLN-EC2 domain for potential HCV inhibition.
• To investigate the efficacy and accessibility of the anti-hOCLN-EC2 mAb in blocking HCV infection in cell culture models.

Main Methods:

• Generation of anti-hOCLN-EC2 monoclonal antibody (mAb) 67-2.
• Assessment of mAb 67-2's inhibitory effect on HCV infection in Huh7.5.1 cells.
• Evaluation of mAb accessibility to occludin from different cellular sides (apical vs. basolateral).
• Western blot analysis to determine antibody specificity for occludin.

Main Results:

• The generated mAb 67-2 significantly inhibited HCV infection in human hepatocyte cell lines.
• mAb 67-2 effectively targeted occludin from the basolateral but not the apical side of hepatocytes.
• Western blot confirmed mAb 67-2 binds to both human and mouse occludin, indicating it doesn't target human-specific residues.
• The antibody demonstrated no adverse effects on cell viability or tight junction barrier function.

Conclusions:

• The anti-hOCLN-EC2 mAb 67-2 is a potent inhibitor of HCV entry, targeting a conserved region of occludin.
• This antibody represents a promising therapeutic candidate for preventing and treating HCV infection, with potential for targeting conserved host factors.
• Further research into this antibody could lead to novel anti-HCV therapeutics independent of viral genotype.