Diferentes estratégias vacinais utilizando o gene CP1002-RS9720 de Corynebacterium pseudotuberculosis para o controle da Linfadenite caseosa

Abstract

We tested the efficacy of the esterase encoded by cp1002_RS09720 from C. pseudotuberculosis biovar ovis in recombinant subunit and DNA caseous lymphadenitis (CLA) vaccines. This target was predicted as one of the best CLA vaccine candidates by mature epitope density (MED) analysis. The gene cp1002_RS09720 was cloned into two different vectors (pAE for subunit vaccine and pTARGET for DNA vaccine). Four groups of 15 mice each were immunized with the recombinant esterase rCP09720 associated with aluminum hydroxide adjuvant (G1), pTARGET/cp09720 as DNA vaccine (G2), a naked pTARGET (G3), or PBS as a negative control (G4). Immunization occurred in two doses intercalated by a 21-days interval. Twenty-one days after the last dose administration, animals were challenged with virulent C. pseudotuberculosis MIC-6 strain. The G1 group showed high levels of IgG1 and IgG2a on days 21 and 42 post immunization and a significant level of IFN- (P0.05), suggesting a Th1 response. Protection levels obtained were 58.3% and 16.6% for G1 and G2, respectively. Thus, the subunit vaccine composed by the recombinant esterase rCP09720 and Al(OH)3 is a promising antigenic formulation to be used as vaccine against CLA.