Uso de uma quimera multiepitópica (rMEPLox) na produção de anticorpos monoclonais contra venenos de aranhas do gênero Loxosceles spp.

• Ano de defesa: 2022
• Autor(a) principal: Tamara Gabriela Fernandes Costa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ICB - DEPARTAMENTO DE BIOQUÍMICA E IMUNOLOGIA; Programa de Pós-Graduação em Bioquímica e Imunologia; UFMG
• Palavras-chave em Português: Veneno da aranha Loxosceles; Metaloprotease; Anticorpo monoclonal; Proteína recombinante multiepitópica; Bioquímica e imunologia; Venenos de Aranha; Loxosceles; Anticorpos monoclonais; Proteínas recombinantes
• Link de acesso: http://hdl.handle.net/1843/50421

Loxoscelism is a serious health issue in the South America. In Brazil three species are involved in the highest notified cases: Loxoceles intermedia, Loxosceles laeta and Loxosceles gaucho. The treatment for these accidents is based on the administration of antivenom produced in animals immunized with Loxosceles crude venom. However, there are some issues related to antivenom production, such as the high number of animals used and the toxicity that the crude venom can cause to producer animals. An aternative approach to improve antivenom production is monoclonal antibodies development (mAbs) against spider venoms components, able to neutralize its toxic effects. In this work, a previously produced non-toxic multiepitopic chimeric protein (rMEPLox), composed of epitopes derived from the main toxin families (sphyngomielinase-D, metalloproteases, and hyaluronidases) of Loxosceles spider venoms, was used as antigen to produce monoclonal antibodies. A selected anti-rMEPLox mAb (Lox-mAb3) reacted with 20 kDa metalloprotease from L. intermedia venom and showed cross-reactivity with metalloproteases from Brazilian and Peruvian Loxosceles laeta and Loxosceles gaucho venoms in immunoassays. The sequence recognized by Lox-mAb3 (184ENNTRTIGPFDYDSIMLYGAY205) corresponds to the C-terminal region of Astacin-like metalloprotease 1 and the amino acid sequence IGPFDYDSI, conserved among the homologs metalloproteases sequences, is important for antibody recognition. Lox-mAb3 neutralizes the fibrinogenolytic activity caused by metalloprotease from L. intermedia spider venom in vitro, which may lead to a decrease in hemorrhagic disturbances caused by Loxosceles envenomation. Other mAbs were produced using rMEPLox as antigen, however, although they recognize rMEPLox they did not recognize Loxosceles venom. Our results show, for the first time, the use of a non-toxic multiepitopic protein for the production of neutralizing monoclonal antibody against a metalloprotease of the medically important Loxosceles venoms. These results contribute for the improvement of therapeutic antivenom production against loxoscelism.