RESUMO
We have reported previously that a recombinant DNA vaccine consisting of four Ehrlichia ruminantium (Welgevonden) open reading frames (ORFs) known as the 1H12 cocktail provided protection against a virulent E. ruminantium (Welgevonden) needle challenge in sheep. In this study, we have investigated the vaccine effectiveness of two other cocktails of E. ruminantium (Welgevonden) ORFs, as well as single ORFs from the 1H12 cocktail, to protect sheep against a virulent needle challenge with the homologous strain. Each individual 1H12 ORF provided protection, but all the animals vaccinated with the other cocktails succumbed to the challenge.
Assuntos
Ehrlichia ruminantium/imunologia , Hidropericárdio/imunologia , Imunização/métodos , Fases de Leitura Aberta/genética , Vacinas de DNA/imunologia , Animais , Ilhas de CpG/genética , Ehrlichia ruminantium/genética , Hidropericárdio/prevenção & controle , Linfócitos/imunologia , Ovinos , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genéticaRESUMO
A 1.2 kb polymorphic fragment from the Gardel isolate of Ehrlichia (formerly Cowdria) ruminantium was used to isolate a 15kb clone from the E. ruminantium Welgevonden LambdaGEM-11 library. This clone, WL2EL1, was subcloned and sequenced. Eight open reading frames (ORFs) were identified. The ORF in WL2EL1 which contained the Welgevonden homologue of the 1.2 kb polymorphic fragment was designated Cowdria polymorphic gene 1 (cpg1). The cpg1 ORF was cloned into pCMViUB, a genetic vaccine vector. Mice and sheep were immunized with pCMViUB/cpg1 by intramuscular injection and gene gun inoculation. Although all of the immunized mice died, there was a trend for mice that received larger amounts of pCMViUB/cpg1 DNA to survive longer. Four out of five sheep immunized with the construct survived lethal challenge.
Assuntos
Vacinas Bacterianas , Ehrlichia ruminantium/genética , Ehrlichia ruminantium/imunologia , Hidropericárdio/prevenção & controle , Fases de Leitura Aberta/imunologia , Doenças dos Ovinos/prevenção & controle , Animais , Clonagem Molecular , Relação Dose-Resposta Imunológica , Genes Bacterianos , Vetores Genéticos , Hidropericárdio/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fases de Leitura Aberta/genética , Polimorfismo Genético , Homologia de Sequência , Ovinos , Doenças dos Ovinos/imunologia , Vacinação/veterináriaRESUMO
Ehrlichia ruminantium GroEL and GroES genes were amplified from E. ruminantium Welgevonden genomic DNA and were cloned into genetic vaccine and Salmonella expression vectors. These constructs were used to inoculate Balb/c and C57BL/6J mice. Both GroEL and GroES induced low levels of protection in Balb/c and C57BL/6J mice immunized with the Salmonella expression vectors. None of the mice inoculated with the genetic vaccine survived. Immunological memory was also tested in these mice and a correlation between splenocyte proliferation and the survival rate was observed.
