Antibody from mice immunized with DNA encoding the carboxyl-disintegrin and cysteine-rich domain (JD9) of the haemorrhagic metalloprotease, Jararhagin, inhibits the main lethal component of viper venom

Envenoming by the Brazilian pit viper, Bothrops jararaca, induces extensive local and systemic haemorrhage in humans. The severe and occasionally leth al outcome of envenoming is prevented only by administration of antivenom w hich is conventionally prepared by hyperimmunization of large animals with an individual venom or a range of venoms. Since snake venoms typically cons ist of numerous molecules, only some of which are toxic, antivenoms are ant igenically crude preparations whose therapeutic value would theoretically b e enhanced by restricting antibody specificity to toxic venom molecules. We report here that high-titre IgG antibody from mice immunized by the GeneGu n with DNA encoding the carboxy-terminal JD9 domain of Jararhagin, a haemor rhage-inducing metalloprotease in B. jararaca venom, extensively neutralize d the main lethal component of B. jararaca venom. This is to our knowledge the first study to apply DNA-based methods to preparation of antivenom; it represents a novel approach with greater immunological specificity and fewe r hazards than conventional systems of antivenom production.