RESUMO
Group C Rotavirus (RVC) has been associated globally with sporadic outbreaks of gastroenteritis in children and adults. RVC also infects animals, and interspecies transmission has been reported as well as its zoonotic potential. Considering its genetic diversity and the absence of effective vaccines, it is important and necessary to develop new generation vaccines against RVC for both humans and animals. The aim of the present study was to develop and characterize an HSV-1-based amplicon vector expressing a human RVC-VP6 protein and evaluate the humoral immune response induced after immunizing BALB/c mice. Local fecal samples positive for RVC were used for isolation and sequencing of the vp6 gene, which phylogenetically belongs to the I2 genotype. We show here that cells infected with the HSV[VP6C] amplicon vector efficiently express the VP6 protein, and induced specific anti-RVC antibodies in mice immunized with HSV[VP6C], in a prime-boost schedule. This work highlights that amplicon vectors are an attractive platform for the generation of safe genetic immunogens against RVC, without the addition of external adjuvants.
Assuntos
Antígenos Virais/genética , Antígenos Virais/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Expressão Gênica , Vetores Genéticos/genética , Herpesvirus Humano 1/genética , Rotavirus/genética , Rotavirus/imunologia , Animais , Anticorpos Antivirais/imunologia , Chlorocebus aethiops , Humanos , Imunidade Humoral , Masculino , Camundongos , Filogenia , Proteínas Recombinantes , Células VeroRESUMO
HSV-1 amplicon vectors encoding heterologous antigens were capable to mediate in situ generation of protein synthesis and to generate a specific immune response to the corresponding antigens. In this study, foot-and-mouth disease (FMD) virus antigens were used to generate a genetic vaccine prototype. The amplicons were designed to provide a high safety profile as they do not express any HSV-1 genes when packaged using a helper virus-free system, and they are able to encapsidate several copies of the transgene or allow the simultaneous expression of different genes. Virus-like particles were produced after cell processing of the delivered DNA. Inoculation of mice with 5 × 10(5) transducing units of amplicon vectors resulted in FMDV-specific humoral responses in the absence of adjuvants, which were dependent on the in situ de novo production of the vector-encoded antigens. Challenge of mice vaccinated with these amplicons with a high dose of live virus, resulted in partial protection, with a significant reduction of viremia. This work highlights the potential use of a HSV-1 amplicon vector platform for generation of safe genetic vaccines.