RESUMO
VP2/VP6 virus like particles (VLPs) are very effective in inducing protection against the rotavirus infection in animal models. Individually, VP6 can also induce protection. However, there is no information about the immunogenicity of VP2. The aim of this work was to evaluate the efficacy of DNA vaccines codifying for VP2 or VP6, alone or combined, to induce protection against the rotavirus infection. Murine rotavirus VP2 and VP6 genes were cloned into the pcDNA3 vector. Adult BALB/c mice were inoculated three times by intramuscular (i.m.) injections with 100 or 200µg of pcDNA3-VP2 or pcDNA3-VP6 alone or co-administered with 100µg of pcDNA3-VP2/100µg of pcDNA3-VP6. Two weeks after the last inoculation, mice were challenged with the wild type murine rotavirus strain epizootic diarrhea of infant mice (EDIMwt). We found that both plasmids, pcDNA3-VP2 and pcDNA3-VP6, were able to induce rotavirus-specific serum antibodies, but not intestinal rotavirus-specific IgA; only 200µg of pcDNA3-VP6 induced 35% protection against the infection. A similar level of protection was found when mice were co-administered with 100µg of pcDNA3-VP2/100µg of pcDNA3-VP6 (1:1 ratio). However, the best protection (up to 58%) occurred when mice were inoculated with 10µg of pcDNA3-VP2/100µg of pcDNA3-VP6 (1:10 ratio). These results indicate that the DNA plasmid expressing VP6 is a better vaccine candidate that the one expressing VP2. However, when co-expressed, VP2 potentiates the immunogenicity and protective efficacy of VP6.
Assuntos
Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/imunologia , Vacinas de DNA/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Proteínas do Capsídeo/genética , Fezes/virologia , Feminino , Imunogenicidade da Vacina , Camundongos , Camundongos Endogâmicos BALB C , Rotavirus , Infecções por Rotavirus/imunologia , Eliminação de Partículas ViraisAssuntos
Doença de Chagas/veterinária , Insetos Vetores/parasitologia , Mamíferos/parasitologia , Triatoma/parasitologia , Animais , Animais Domésticos , Doença de Chagas/epidemiologia , Doença de Chagas/transmissão , Reservatórios de Doenças/veterinária , México/epidemiologia , Prevalência , Trypanosoma cruzi/isolamento & purificaçãoAssuntos
Doença de Chagas/transmissão , Vetores de Doenças , Triatoma/parasitologia , Animais , Feminino , Masculino , México , CamundongosRESUMO
Wild vectors and reservoir hosts of Trypanosoma cruzi were surveyed from February 1993 to June 1994 in Ticumán (18 degrees 46'N, 99 degrees 07'W), Mexico (Deciduous Tropical Forest). Direct faeces examination showed that 87% of Triatoma pallidipennis hosted the parasite; T. cruzi forms were present in cultures inoculated with faeces of fifty 67% triatomine bugs and thirty CD-1 strain mice (10 d old) inoculated (peritoneum) with faeces of positive insects T. cruzi amastigotes were found in heart 67%, kidneys 47%, liver 80%, lungs 50%, oesophagus 60%, skin 23%, spleen 73% and stomach 60%. T. cruzi was isolated by direct blood examination from seven 21% chiropterans and five 38% rodents and T. cruzi forms were present in cultures inoculated with blood of twenty-three 68% chiropterans and seven 54% rodents and T. cruzi amastigotes were seen in the kidneys of one 3% chiropterans and four 31% rodents and only in one Pteronotus parnellii mexicanus, organisms were seen in skin 2%. There was no association between organs and T. cruzi infection (p > 0.05).
