RESUMO
An optimized VP2 gene from the current prevalent CPV strain (new CPV-2a) in China was expressed in a baculovirus expression system. It was found that the VP2 proteins assembled into virus-like particles (VLPs) with antigenic properties similar to those of natural CPV and with an especially high hemagglutination (HA) titer (1:2(20)). Dogs intramuscularly or orally immunized with VLPs produced antibodies against CPV with >1:80 hemagglutination inhibition (HI) units for at least 3 months. The CPV VLPs could be considered for use as a vaccine against CPV or as a platform for research on chimeric VLP vaccines against other diseases.
Assuntos
Baculoviridae , Vetores Genéticos , Parvovirus Canino/genética , Proteínas Estruturais Virais/metabolismo , Virossomos/metabolismo , Administração Oral , Animais , Anticorpos Antivirais/sangue , China , Cães , Injeções Intramusculares , Multimerização Proteica , Vacinas Virossomais/administração & dosagem , Vacinas Virossomais/genética , Vacinas Virossomais/imunologia , Proteínas Estruturais Virais/genética , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Vacinas Virais/imunologia , Virossomos/genéticaRESUMO
This study aims to investigate the effects of Tween 80 on curdlan production, cell growth, and glucosyltransferase activity. The addition of Tween 80 to the culture medium increased curdlan production. However, curdlan production did not increase further when excessive Tween 80 (>0.3% Tween 80) was added to the culture medium. The addition of Tween 80 to the culture medium did not affect cell growth. The glucosyltransferase activity involved in the curdlan synthesis increased with the increase of Tween 80 concentration. The glucosyltransferase activity did not increase further when excessive Tween 80 (>0.3% Tween 80) was added to the culture medium. Maximum curdlan was observed at day 5 and then levelled off. The biomass continued to increase until the end of the experimental period (6d). Maximum glucosyltransferase activity was also observed at day 5 and decreased thereafter. The results indicate that the enhanced curdlan production by Tween 80 is highly correlated with glucosyltransferase activity.