Avaliação de uma vacina de aplicação intravaginal contra o Herpesvírus bovino tipo 5 (BoHV-5) associada a subunidade B recombinante da enterotoxina termolábil de Escherichia coli (rLTB)

• Autor(a) principal: Siedler, Bianca Sica
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFPel - Guaiaca
• Texto Completo: http://repositorio.ufpel.edu.br/handle/ri/2466
• topic: Veterinária; Imunidade de mucosas; Vacina intravaginal; BoHV-5; Mucosal immunity; Intravaginal vaccine; BoHV-5; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

Mucosal immune system represents the initial barrier against many pathogens, including bovine herpesviruses (BoHV). After infection of mucous membranes, mainly nasal and genital, these viruses disseminate locally followed by viremia and neural spread. Innate defense mechanisms along with adaptive immunity confer protection to mucosal surfaces. In this context, secretory IgA (sIgA) plays an essential role in the mucosal humoral immunity, conferring protection to these body surfaces through different mechanisms, including viral neutralization. This class of antibody predominates in the vaginal mucosa of cattle playing an important role in the local defense against infections. Considering the importance of this infection route in herpesviruses pathogenesis, there is a growing interest in the development of vaccines that provide mucosal immunity against these viruses. In the present study, eight cows were divided in two groups (G1 and G2) and inoculated intravaginally with inactivated BoHV-5 associated with recombinant Escherichia coli heat-labile enterotoxin B subunit (rLTB) and xanthan (G1) and inactivated BoHV-5 associated with xanthan (G2). Local and systemic humoral immune response (IgA and IgG) induced after inoculation was measured by indirect ELISA. An increment in the levels of IgA and IgG was detected in sera, nasal and genital mucosa of all the immunized animals. Furthermore, the relative expression of interleukins 2 and 13 (IL-2 and IL-13) was investigated by real-time PCR indicating an increased mRNA expression of these cytokines in leukocytes collected from animals immunized with the experimental vaccine. These results demonstrate that the experimental intravaginal BoHV-5 vaccine induced a local and systemic immune response in cattle. The results also corroborated the immunostimulant activity of the rLTB in mucosal membranes and confirmed the use of xanthan as a delivery system for intravaginal vaccines. Our data also reinforce the importance of this route for administration of vaccines focused on providing local protection against pathogens.