Imunização de bovinos com dois peptídeos recombinantes derivados do peptídeo sbm7462®. Resposta de linfonodos e alterações histológicas do intestino do carrapato Rhipicephalus (Boophilus) microplus (Canestrini, 1887)

• Autor(a) principal: Tafur Gómez, Gabriel Andres
• 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/123456789/5091
• topic: Carrapatos; Bovinos; Vacina; Ticks; Cattle; Vaccine; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::MEDICINA VETERINARIA PREVENTIVA

Ticks are important to public health and animal production because of their ability to transmit various infectious agents. Among ticks, Rhipicephalus microplus is responsible for economic losses in tropical and subtropical countries. Among the ways to control this ectoparasite, the immune option is viable, which doesn t generate resistant tick populations and offers safety to the animal products. The synthetic vaccine SBm7462® contains three immunogenic epitopes (4822, 4824 and 4823) derived from the Bm86 protein. Genetic analysis showed that the fragement corresponding to the SBm7462® is conserved in the population of R. microplus from different regions on South America. To evaluate the events of cellular immunity in calves and histology changes in female R. microplus. Previously were designed and constructed two genes expressed in Pichia pastoris Km71 strain. The rBmseq1 gene was designed to express immunogenic epitopes in tandem and rBmseq4 gene designed expressed this without repetitions. The recombinant peptides were recovered from the extracellular medium and were characterized by SDS-PAGE and Western blotting. These peptides were inoculated three times at intervals of thirty days in five Bos taurus taurus calves at doses of 2 mg plus 1.5 mg saponin. Afterwards, the lymph nodes were collected and processed histologically. Histological sections were stained by (H&E) and immunohistochemical staining for peroxidase-anti-peroxidase (PAP). It was shown that they developed a T-dependent response with immunity induction in animals immunized. Hence, showed clear structures whit confers immunity and affinity in animals immunized whit rBmseq4. However, 21 days after the last immunization, the challenge was made with R. microplus 4500 larvae per animal. At 21 days with the beginning of fallen females, these were randomly selected from each group. R. microplus females fed on animal s rBmseq1 group showed integrity of the intestinal epithelium, similar to control group. However, guts of ticks fed on animal s rBmseq4 group showed denudation and erosion of basal membrane cell. It demonstrates the peptide rBmseq4 peptide has a great ability to generate immune responses which induce adverse reactions in R. microplus.