HIGH-LEVEL EXPRESSION OF EQUINE HERPESVIRUS-1 GLYCOPROTEIN-D AND GLYCOPROTEIN-H AND THEIR ROLE IN PROTECTION AGAINST VIRUS CHALLENGE IN THEC3H (H-2K(K)) MURINE MODEL

N and C-terminal truncated forms of equine herpesvirus 1 (EHV 1) glyco proteins gD and gH were expressed in baculovirus resulting in the prod uction of secreted recombinant proteins. A carboxy-terminal histidine tag was included on each of the genes for protein isolation by nickel affinity chromatography. Recombinant gD was recognized by three gD spe cific monoclonal antibodies, 20C4, 5H6 and F3132. F3132 is a conformat ionally dependent monoclonal antibody with virus neutralizing activity . Expression of gH was confirmed by reacting the protein with the gH p eptide specific antiserum R319. The truncated gD gene was also express ed as a beta-galactosidase fusion protein which was purified from E. c oli by nickel affinity chromatography. C3H mice were inoculated with p urified recombinant gD or gH or insect cells which had been infected w ith recombinant baculoviruses. Mice were subsequently challenged with EHV 1. Purified recombinant baculovirus gD provided the most protectio n and produced high levels of virus neutralizing antibodies. The gD fu sion protein was less effective at protecting mice and insect cells in fected with either of the recombinant baculoviruses or purified recomb inant gH were poor at conferring protection. The results emphasize the importance of using purified proteins in Vaccine formulations and of including EHV 1 gD as a component of a subunit vaccine. (C) 1997 Elsev ier Science B.V.