Caracterização da resposta imune a diferentes componentes oriundos do veneno de Crotalus durissus terrificus em cavalos imunizados para produção de soro anticrotálico

Abstract

Snakebite accidents are very prevalent in Brazil and many other tropical countries, being on the list of “neglected tropical diseases” by the World Health Organization. Crotalus durissus terrificus is responsible for about 9% of all snakebite accidents that occur in Brazil. Its venom is composed of proteins and polypeptides that are responsible for several injuries that occur in the body. The major constituent of crotalic venom is crotoxin, accounting for about 60% of total venom. Antivenom serum produced for treatment purposes, still complies the effectiveness criteria similar to those when it was developed, that is, in the beginning of the 20th century, being the only treatment to neutralize the effects caused in the organism by the venom. Although the application of antiohidic serum is the most suitable treatment for snakebites, the shorter the elapsed time of the bite, the greater the effectiveness of the serum in neutralizing the effects of the venom, and the lesser the quantity and severity of side effects from this therapy. New technologies have emerged to improve the efficacy and minimize the side effects of serums, vaccines and drugs, including the use of peptides as immunogenic epitopes. The objective of this work was to characterize the cellular and humoral immune response to synthetic peptides derived from crotoxin in horses used for the production of anticrotalic serum. For this purpose, bioinformatics tools were used to predict possible immunogenic epitopes that were later synthesized and purified. The characterization of the immune response was carried out through enzyme-linked immunosorbent assays (ELISA) for antibody titration and cytokine detection and cell proliferation assays from peripheral blood mononuclear cells of horses used for the production of anticrotalic serum. We were able to observe a cellular and humoral response against the synthetic peptides of the CA and CB fractions of the crotoxin, with a greater antibody response against the peptide from the CB fraction compared to the response presented against peptides from the CA fraction. The production of the IL-4 and IFN cytokines in culture supernatant of mononuclear cells stimulated with the peptides was discrete, requiring a more detailed investigation in order to verify a possible inhibitory property by the peptides.