Epitope-based antibody development against metalloproteinases and phospholipases A₂ from Deinagkistrodon acutus venom

Deinagkistrodon acutus, or the hundred-pace snake, poses severe health risks due to its venom. Envenomation by this snake leads to complications such as hemorrhage, edema, and coagulopathy. Traditional antivenoms are limited by venom variability and often contain non-neutralizing antibodies, highlighting the need for more precise and effective immunogens.

This study utilized epitope-based antibody technology to develop a targeted sera against venom metalloproteinases (MPs) and phospholipases A₂ (PLA₂s). Twelve antigenic epitopes were identified via bioinformatics, leading to the design of a composite antigen peptide, EpiMPLA. It was engineered to be expressed via two expression systems, resulting in the recombinant immunogens, ProMPLA and p2AMPLA.

Immunization with ProMPLA and p2AMPLA produced robust antibody responses in mice, effectively inhibiting MPs and PLA₂s. In vitro assays demonstrated that sera from immunized mice reduced the activity of these venom enzymes, minimized venom-induced hemorrhage and edema, and restored blood coagulation. At a venom dose of 2×LD₅₀, all mice in the control group died, while survival rates were 90% for anti-ProMPLA and 70% for anti-p2AMPLA.

The EpiMPLA epitope represents a promising candidate for generating neutralizing antibodies against D. acutusvenom, demonstrating its potential to address critical gaps in current antivenom therapy. These findings not only validate the feasibility of epitope-based antivenom development but also pave the way for further research to optimize this strategy.