Bioinformatics and multiepitope DNA immunization to design rational snake antivenom

Area of Science:

• * Biochemistry and Molecular Biology
• * Immunology
• * Bioinformatics

Background:

• * Snake venom is a complex mixture of proteins, making purification and characterization challenging.
• * Conventional antivenoms derived from animal sera have unknown specificities and can cause adverse reactions.
• * There is a need for rational design of toxin-targeted antivenoms.

Purpose of the Study:

• * To design a more rational, toxin-targeted antivenom using molecular sequence analysis and DNA immunization.
• * To develop a novel bioinformatic strategy for identifying immunogenic epitopes from snake venom glands.
• * To engineer a synthetic multiepitope DNA immunogen for enhanced antivenom efficacy.

Main Methods:

• * Bioinformatic analysis of an Echis ocellatus venom gland cDNA library to identify snake venom metalloproteinase (SVMP) epitopes.
• * Engineering of seven predicted SVMP epitopes into a single synthetic multiepitope DNA immunogen (epitope string).
• * Comparison of antiserum raised against the epitope string with conventional whole-venom antivenom.

Main Results:

• * The epitope string antiserum showed specificities to multiple SVMPs in Echis ocellatus and other viper venoms.
• * Antiserum cross-specifically neutralized hemorrhage induced by Echis ocellatus and Cerastes cerastes cerastes venoms.
• * Predicted in silico epitope representation was confirmed by antibody specificities.

Conclusions:

• * The study provides valuable sequence and structure/function information for viper venom hemorrhagins.
• * A new conceptual approach to toxin-specific antivenom design has been established, marking a significant advancement.
• * The methodology is adaptable for immunotherapy design against numerous, diverse, and poorly characterized targets.