IMMUNOGENIC AND PROTECTIVE PROPERTIES OF CHICKEN ANEMIA VIRUS PROTEINS EXPRESSED BY BACULOVIRUS

The coding information for three putative chicken anaemia virus protei ns (VP1, VP2, VP3) was inserted into a baculovirus vector and expresse d in insect cells. The immunogenic properties of the chicken anaemia v irus (CAV) proteins produced separately or together in insect-cell cul tures were analysed by inoculating them into chickens, Only lysates of insect cells which have synthesised equivalent amounts of all three r ecombinant CAV proteins or cells which synthesised mainly VP1 plus VP2 induced neutralising antibodies directed against CAV in inoculated ch ickens. Progeny of those chickens were protected against clinical dise ase after CAV challenge. Inoculation of a mixture of lysates of cells that were separately infected with VP1-, VP2- and VP3-recombinant bacu lovirus did not induce significant levels of neutralising antibody dir ected against CAV and their progeny were Mot protected against CAV cha llenge. Our results indicate that expression in the same cell of at le ast two CAV proteins, VP1 plus VP2, is required to obtain sufficient p rotection in chickens. Therefore, recombinant CAV proteins produced by , baculovirus vectors can be used as a sub-unit vaccine against CAV in fections.