ANTIBODY-RESPONSES IN RABBITS AFTER SINGLE IMMUNIZATION WITH VIRAL GLYCOPROTEIN-LOADED MICROSPHERES OR ISCOMS

Antigenic and adjuvant activities of microspheres and ISCOM (immunity stimulating complexes) with incorporated envelope glycoproteins of bov ine herpesvirus-1 (BHV-1) were tested in long-term (31-week) experimen ts in rabbits, Similar antibody responses were recorded after a single intradermal immunization with BHV-1 glycoproteins incorporated into I SCOM nanoparticles or microspheres prepared from linear co-polymers (5 0/50) of DL-lactic and glycolic acids. Stronger, longer and markedly b iphasic antibody responses were observed in rabbits immunized with BHV -1 M-DL-LA microspheres prepared from branched oligoesters of DL-lacti c acid and mannitol. Indirect evidence of the incorporation of the vir al envelope proteins into any type of microspheres or ISCOMs was obtai ned by immunoblotting. A set of precipitation lines was detected in ra bbit blood sera collected 7 weeks after the immunization with microsph ere-or ISCOM-entrapped glycoproteins. A similar, but more numerous, se t was found in the control serum collected from cattle after natural i nfection by BHV-1. (C) 1997 Elsevier Science B.V.