Tese
Uso de uma quimera multiepitópica (rMEPLox) na produção de anticorpos monoclonais contra venenos de aranhas do gênero Loxosceles spp.
Fecha
2022-03-23Autor
Tamara Gabriela Fernandes Costa
Institución
Resumen
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.