PROTECTIVE IMMUNITY OF BOVINE HERPESVIRUS-1 (BHV-1) RECOMBINANTS WHICH EXPRESS PSEUDORABIES VIRUS (PRV) GLYCOPROTEINS GB, GC, GD AND GE

We have constructed recombinants of bovine herpesvirus-1 (BHV-1) which express pseudorabies virus (PRV) gB, gC, gD or gE either individually or in combination. To test the protective immunity, mice were inocula ted with these BHV-1 recombinants and challenged three weeks later wit h virulent PRV. A BHV-1 recombinant, BHV-1/TF7-1, which express PRV gC , gD, gE and gI but not PRV gB, protected all 7 mice from the challeng e with 20 LD(50) virulent PRV and 6 cut of 7 from the challenge with 1 00 LD(50) PRV, while one dead mice survived for 5 days after the chall enge. All the control mice died in 3 days. BHV-1 recombinants which ex press PRV gB, gC and gD individually also gave some protection but not so effective as BHV/TF7-1. Before challenging with virulent PRV, sera were collected from immunized mice and antibody against PRV was assay ed. Western blot analyses indicated that all the recombinants induced antibody in mice against PRV gB,gC or go individually or in combinatio n. Virus neutralizing (VN) titer against PRV was highest in mice which were inoculated with BHV-1/ITF6-1, which expresses PRV gB. BHV-1/TF7- 1, which was more effective to protect mice from the challenge of viru lent PRV, induced lower VN titer.