CONSTRUCTION AND CHARACTERIZATION OF E3-DELETED BOVINE ADENOVIRUS TYPE-3 EXPRESSING FULL-LENGTH AND TRUNCATED FORM OF BOVINE HERPESVIRUS TYPE-1 GLYCOPROTEIN GD

Using the homologous recombination machinery of E. coil, a 1.245-kb de letion was introduced in the E3 region of bovine adenovirus 3 (BAV3) g enomic DNA cloned in a plasmid. Transfection of the restriction enzyme -excised, linear E3-deleted BAV3 genomic DNA into primary fetal bovine retina cells produced infectious virus (BAV3.E3d), suggesting that al l the E3-specific open reading frames are nonessential for virus repli cation in vitro. Using a similar approach, we constructed replication- competent (BAV3.E3gD and BAV3.E3gDt) BAV3 recombinant expressing full- length (gD) or truncated (gDt) glycoprotein of bovine herpes virus 1. Recombinant go and got proteins expressed by BAV3.E3gD and BAV3.E3gDt, respectively, were recognized by go-specific monoclonal antibodies di rected against conformational epitopes, suggesting that antigenicity o f recombinant go and got was similar to that of the native go expresse d in bovine herpes virus 1-infected cells. Intranasal immunization of cotton rats induced strong gD- and BAV3-specific IgA and IgG immune re sponses. These results suggest that replication-competent bovine adeno virus 3-based vectors have potential for the delivery of vaccine antig ens to the mucosal surfaces of animals. (C) 1998 Academic Press.