Avaliação da resposta imune de camundongos BALB/c imunizados com o peptídeo SBm7462®, anti Rhipicephalus (Boophilus) microplus, expresso em plantas (Arabidopsis thaliana)

• Autor(a) principal: Kalks, Karlos Henrique Martins
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5065
• topic: Carrapatos; Controle; SBm7462; Ticks; Control; SBm7462; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::MEDICINA VETERINARIA PREVENTIVA

The damage due to infestation of Rhipicephalus (Boophilus) microplus has been estimated at billions of dollars in the tropical and subtropical countries. The most commonly used forms of combat for this ectoparasite is mainly based on the use of chemical acaricides. Seeking an alternative way to control the parasite, the vaccine was developed synthetic anti R. (B.) microplus (SBm7462®). The synthetic vaccine SBm7462® contains three immunogenic epitopes (4822, 4824 and 4823) derived from the Bm86 protein. Genetic analysis showed that the fragment corresponding to SBm7462® is conserved across populations R. (B.) microplus from different regions in South America, however, the production of this vaccine on an industrial scale would cost very high. Therefore, alternative methods of production are being developed. The use of plants as bioreactors for production of heterologous proteins is a very attractive approach, since the transgenic plants are one of the most economical systems for protein production on industrial scale. The objective was to study the immune response of mice immunized orally with transgenic Arabidopsis thaliana expressing the recombinant peptide rBm7462. For this, seeds processed in a previous work were grown until the fifth generation. After confirmation of the production of the peptide, 0.5 g of leaves of transformed plants were administered orally to BALB/c, three times (interrupted by 3 weeks), as well as 200μL of total soluble protein extract, inoculated subcutaneously. After 9 weeks, during which blood samples were collected from animals, weekly, they were euthanized for collection of lymph nodes and ileum. The results showed that it was not possible to detect levels of IgG anti-rBm7462 in mice immunized orally with leaves of transgenic plants expressing the peptide rBm7462, as well as in mice immunized with total soluble protein extracts of these plants, while the indirect ELISA method was used. However, the lymph nodes of immunized animals showed microscopic changes related to immune response and markings, by immunohistochemistry, for the peptide rBm7462. These observations led to the conclusion that the antigen dose was given to the animals sub-antigenic which may have stimulated mechanisms of tolerance to the antigen. What makes a necessary adjustment in the doses given to animals. Seeds used strains derived from 2NF allowed for the preparation of the fifth generation of transformed plants, indicating that the gene seq2, responsible for the synthesis of peptide rBm7462 probably is homozygous. What it indicates the genomic stability and viability of producing the antigen in transgenic plants.