Toxicity of crude and detoxified Tityus serrulatus venom in anti-venom-producing sheep.

Specific anti-venom used to treat scorpion envenomation is usually obtained from horses after hyperimmunization with crude scorpion venom. However, immunized animals often become ill because of the toxic effects of the immunogens used. This study was conducted to evaluate the toxic and immunogenic activities of crude and detoxified Tityus serrulatus (Ts) venom in sheep during the production of anti-scorpionic anti-venom. Sheep were categorized into three groups: G1, control, immunized with buffer only; G2, immunized with crude Ts venom; and G3, immunized with glutaraldehyde-detoxified Ts venom. All animals were subjected to clinical exams and supplementary tests. G2 sheep showed mild clinical changes, but the other groups tolerated the immunization program well. Specific antibodies generated in animals immunized with either Ts crude venom or glutaraldehyde-detoxified Ts venom recognized the crude Ts venom in both assays. To evaluate the lethality neutralization potential of the produced sera, individual serum samples were pre-incubated with Ts crude venom, then subcutaneously injected into mice. Efficient immune protection of 56.3% and 43.8% against Ts crude venom was observed in G2 and G3, respectively. Overall, the results of this study support the use of sheep and glutaraldehyde-detoxified Ts venom for alternative production of specific anti-venom.

Preclinical testing of Peruvian anti-bothropic anti-venom against Bothrops andianus snake venom.

Bothrops andianus is a venomous snake found in the area of Machu Picchu (Peru). Its venom is not included in the antigenic pool used for production of the Peruvian anti-bothropic anti-venom. B. andianus venom can elicit many biological effects such as hemorrhage, hemolysis, proteolytic activity and lethality. The Peruvian anti-bothropic anti-venom displays consistent cross-reactivity with B. andianus venom, by ELISA and Western Blotting and is also effective in neutralizing the venom's toxic activities.

An in vivo protective response against toxic effects of the dermonecrotic protein from Loxosceles intermedia spider venom elicited by synthetic epitopes.

Loxoscelism is a necrotic-hemolytic syndrome caused by bites of brown spiders belonging to the genus Loxosceles. Many approaches for the treatment of Loxosceles poisoning have already been proposed, among which administration of specific antivenom is thought to be the more specific. We have evaluated the use of peptides as immunogen to raise in rabbits an antibody response that could protect animals from a challenge by the Loxtox isoform LiD1, one of the main toxic component of Loxosceles intermedia venom. Six antigenic regions of LiD1 were mapped by using the SPOT method. The corresponding peptides were further chemically synthesized, mixed, and used as immunogens in rabbits. Control animal received recombinant LiD1 alone or together with peptides. We found that the rabbit antibody response to peptides was cross-reactive with LiD1, although only one peptide from the mix of six was immunogenic. The dermonecrotic, hemorrhagic and oedema forming activities induced by LiD1 in naïve rabbits were inhibited by 82%, 35% and 35% respectively, by preincubation of LiD1 with anti-peptide antibodies prepared from immunized rabbits. Animals that were immunized with peptides or LiD1r, were found to be protected from the dermonecrotic, hemorrhagic and oedema forming activities induced by a challenge with LiD1. The protection conferred by peptides was, however, lower than that provided by the peptide protein combination or by the full-length protein. These results encourage us in the utilization of synthetic peptides for therapeutic serum development or vaccination approaches.