RESUMO
The synthetic vaccine SBm7462 is based on three immunogenic epitopes (4822, 4823 and 4824) contained within protein Bm86 derived from the Australian Yeerongpilly strain of the tick Rhipicephalus (Boophilus) microplus. Twenty strains of the tick originating from Brazil, Argentina, Colombia and Uruguay were analysed in order to identify differences compared with sequences present in components of vaccine SBm7462. For each parasite population, three cDNA fragments containing the nucleotides coding for the epitopes 4822, 4824 and 4823 were sequenced, and the amino acid sequences were deduced and compared with those of the homologous bm86 gene. The results indicate that the epitope sequences of vaccine SBm7462 are conserved in the South American populations of the tick. The conservation of such sequences is very important for the immunological response of different populations of R. (B.) microplus.
Assuntos
Doenças dos Bovinos/prevenção & controle , Rhipicephalus/imunologia , Infestações por Carrapato/veterinária , Vacinas Sintéticas/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Doenças dos Bovinos/parasitologia , Sequência Conservada , DNA Complementar/química , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Variação Genética , RNA/genética , Rhipicephalus/genética , Alinhamento de Sequência/veterinária , América do Sul , Infestações por Carrapato/prevenção & controle , Vacinas Sintéticas/química , Vacinas Sintéticas/genéticaRESUMO
The synthetic anti-Boophilus microplus vaccine SBm7462 derived from the tick intestinal protein, Bm86, induced a protective immune response when emulsified in saponin and used in cattle. Using a mice model, and with the objective of improving the vaccine by continual peptide release, it was encapsulated in PLGA 50:50 microspheres and inoculated in BALB/c mice to assess the immunological response by detection of anti-peptide IgGs. Comparative studies were made with the peptide emulsified in saponin and with another synthetic vaccine, and the microsphere/peptide was characterized for efficiency of encapsulation, in vitro release profile, morphology, size, peptide integrity after encapsulation and stability in different pHs. The findings showed that saponin enhances a better immune response from SBm7462 and that the PLGA 50:50 microspheres are suitable for use with this peptide.
