Presentation of antigenic sites from foot-and-mouth disease virus on the surface of baculovirus and in the membrane of infected cells

We describe the construction of recombinant baculoviruses displaying on the ir surface and in the membrane of infected cells the small, immunodominant antigenic site (site A) or the large polyprotein (P1) coding for the four s tructural proteins of foot-and-mouth disease virus (FMDV). The coding seque nces were inserted in the amino-terminus of gp64, the major glycoprotein of the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). Following infection of insect cells with the recombinant baculoviruses, th e cellular localization of the chimaeric proteins as well as their presence in the surface of extracellular viruses was assessed by immunofluorescence microscopy and Western blot. The antigenicity of the recombinant viruses w as studied by competitive ELISAs, which showed that although both recombina nt viruses were able to compete with FMDV-specific monoclonal antibodies (M Abs), their patterns of reactivity were different. The results suggest that this eukaryotic display system could be an alternative method of presentat ion of foreign antigens in a multimeric form as a new approach to biosynthe tic vaccines.