Inverted terminal repeats from adeno-associated virus-2 enhance the expression of the chimeric E2 glycoprotein gene of classical swine fever virus

Abstract

Aim. To assess the effect of insertion of inverted terminal repeats from human adeno-associ-ated virus-2 into plasmid vector on the expression of the chimeric E2 glycoprotein gene of classical swine fever virus and immunogenicity of the developed candidate marker DNA-vaccines against classical swine fever. Methods. Confocal laser scanning microscopy, fluo-rescence-activated cell sorting and western blot analysis were used to study chimeric protein expression in HEK293 cells. The antibodies specific to E2 of classical swine fever virus were detected by ELISA. Results. We show that the insertion of inverted terminal repeats into a plasmid vector results in considerable enhancement of the chimeric E2 expression in HEK293 in vitro . At the same time, it does not significantly influence in vitro transgene retention . The vector containing inverted terminal repeats from human adeno-associated virus-2 elicits anti-E2 antibodies titer significantly higher as compared to the initial vector without repeats. Conclusions. The insertion of inverted terminal repeats from human adeno-associated virus-2 into the candidate marker DNA-vaccine against classical swine fever results in a significant increase of the chimeric