Evaluation of the recombinant E2 glycoprotein of bovine viral diarrhoea virus (BVDV) as inmunogen in cattle

CHIMENO ZOTH SA; MORREL E; LEUNDA MR; CANTON G; FERRER MF; TABOGA OA; PALMA E; PICCONE M

Bariloche, Río Negro

Congreso; Annual Meeting XXXIX SAIB Protein Symposium,; 2003

Bovine viral diarrhoea virus  (BVDV) is a member of the pestivirus genus, within the Flaviviridae family. This RNA virus is an important pathogen of cattle, causing significant economic losses world-wide. The E2 envelope glycoprotein is highly antigenic and elicits the production of neutralizing antibodies in the host after vaccination with live or killed vaccines. In previous reports, we  expressed E2 in Sf9 insect cells. When mice and rabbits were immunized with the recombinant E2, it demonstrated to have immunological properties similar to those of the native viral protein. The aim of this work was to determine the serological responses of cattle to the recombinant E2 glycoprotein and the protection against challenge. Animals were immunized with cellular extracts obtained from Sf9 infected with recombinant baculovirus expressing E2 and they were challenged with NADL strain of BVDV. Clinical parameters were recorded daily and samples of serum were evaluated by neutralization test. Viral isolation was performed from buffy coat, nasal and ocullar swabs. Animals immunized with recombinant E2 developed higher neutralizating antibodies titers which increased in shorter time than control groups (one of which included an inactivated vaccine). These results indicate that E2 expressed in Sf9 cells stimulated a specific BVDV neutralizing response that lasted for at least 5 months post vaccination.