RESUMO
AIM: DNA vaccines expressing protective domain of surface protective antigen A(spaA)of Erysipelothrix rhusiopathiae have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies in murine models. METHODS: This paper report using a DNA vaccine expressing a fusion of the spaA protein and various elements, such as a secretion leader sequence from the highly expressed human gene encoding alpha1-antitrypsin (AAT), a highly soluble and stably folded domain from the rat cartilage oligomerization matrix protein (COMP), and three copies of the complement component, C3d3, to enhance the titers of neutralizing spaA-specific antibody. RESULTS: Analysis of titers of the antibody raised in vaccinated mice at different time points indicated that immunizations with the DNA expressing pcDNA3-AAT-COMP-spaAN-3C3d((pcD-ACSC)) had higher titers than pcDNA3-spaA(N)(pcD-S) at weeks 4. Furthermore, the immune protective efficacy of the spaA-chimeras was demonstrated by lethal challenge with a virulent homologous strain 1249 against immunized mice. CONCLUSION: These results suggest that using a plasmid vector containing a strong heterologous signal sequence that mediate efficient antigen secretion in vivo and a fused piece of sequence improving antigens solubility, as well as C3d3, genetic adjuvant, could enhance the antibody responses level. This approach might be an efficient way to improve the antibody level of spaA(N) DNA vaccination.
Assuntos
Anticorpos/imunologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Erysipelothrix/imunologia , Imunização , Plasmídeos/genética , Proteínas Recombinantes de Fusão/genética , Vacinas de DNA/imunologia , Animais , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Linhagem Celular , Proliferação de Células , Feminino , Expressão Gênica , Engenharia Genética , Humanos , Camundongos , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Fatores de Tempo , Vacinas de DNA/genéticaRESUMO
AIM: To study the localization of the antioxidant protein thioredoxin peroxidase (TPx) of Echinococcus granulosus (EgTPx) in the protoscoleces (PSC) of parasite. METHODS: The protoscoleces of E.granulosus were aspirated and pooled from sheep liver hydatid cysts. After digested by pepsin, the sedimented protoscoleces were used for paraffin sections. The localization of the antioxidant protein TPx of EgTPx was determined by using(polyclonal antibody against rEgTPx) and indirect immunofluorescence staining. RESULTS: Indirect immunofluorescence staining analysis indicated that the rEgTPx was mainly distributed in tegument, subtegument and calcareous corpuscle cells of the protoscolex. CONCLUSION: The wide distribution and large sites of EgTPx in the parasite hare been clearly determined, which will help further investigation into the biological functions and application of TPx protein.
