Immunological assessment of mice hyperimmunized with native and Cobalt-60-irradiated Bothrops venoms

Abstract

ELISA was used to evaluate and compare the humoral immune response of Swiss mice during hyperimmunization with native and Cobalt-60-irradiated (60Co) venoms of Bothrops jararaca, B. jararacussu and B. moojeni. Potency and neutralization were evaluated by in vitro challenges. After hyperimmunization, immunity was observed by in vivo challenge, and the side effects were assessed. Animal immunization with one LD50 of each venom were performed on days 1, 15, 21, 30 and 45, when blood samples were collected; challenges were done on the 60th day. Results showed that ELISA was efficient in evaluating and comparing mouse immune response during hyperimmunization. Serum titres produced with natural venom were similar to those produced with irradiated venom. Immunogenic capacity was maintained after 60Co-irradiation. The sera produced with native venom showed neutralizing potency and capacity similar to those of the sera produced with irradiated venom. All antibodies were able to neutralize five LD50 from these venoms. Clinical alterations were minimal during hyperimmunization with irradiated venom. However, necrosis and death occurred in animals inoculated with the native venom.