ANTIBODY-RESPONSES AND PROTECTIVE IMMUNITY TO RECOMBINANT VACCINIA VIRUS-EXPRESSED BLUETONGUE VIRUS-ANTIGENS

The role of individual viral proteins in the immune response to blueto ngue virus (BTV) is not clearly understood. To investigate the contrib utions of the outer capsid proteins, VP2 and VP5, and possible interac tions between them, these proteins were expressed from recombinant vac cinia viruses either as individual proteins or together in double reco mbinants, or with the core protein VP7 in a triple recombinant. Compar ison of the immunogenicity of the vaccinia expressed proteins with BTV expressed proteins was carried out by inoculation of rabbits and shee p. Each of the recombinants was capable of stimulating an anti-BTV ant ibody response, although there was a wide range in the level of respon se between animals and species. Vaccinia-expressed VP2 was poorly immu nogenic, particularly in rabbits. VP5, on the whole, stimulated higher ELISA titers in rabbits and sheep and in some animals in both species was able to stimulate virus neutralizing antibodies. When the protect ive efficacy of VP2 and VP5 was tested in sheep, vaccinia-expressed VP 2, VP5 and VP2 + VP5 were protective, with the most consistent protect ion being in groups immunized with both proteins. (C) 1997 Elsevier Sc ience B.V.