Optimization of bovine coronavirus hemagglutinin-estrase glycoprotein expression in E3 deleted bovine adenovirus-3.
Adenoviral vectors expressing foreign genes have many desirable properties in applications such as vaccination. Recently, we have generated replication-competent (E3 deleted) bovine adenovirus-3 (BAV-3) recombinants expressing significant amounts of glycoprotein D (gD) of bovine herpesvirus-1 (a DNA virus). However, attempts to express the RNA virus genes using the same strategy were not successful. In an effort to optimize the expression, we have constructed several BAV-3 recombinants carrying the hemagglutinin esterase (HE) gene of bovine coronavirus (BCV) in the E3 region with or without exogenous transcription control elements. The expression studies suggest that the introduction of a 137 bp chimeric intron upstream of the HE cDNA is able to increase the level of HE gene expression. The introduction of a SV40 early promoter or human cytomegalovirus (HCMV) immediate early (IE) promoter into the expression cassette changed the kinetics of the HE expression. However, the recombinant BAV-3 containing HE under the HCMV IE promoter replicated less efficiently than the wild-type BAV-3. These studies should prove useful in expression of other RNA viral genes in the E3 region of BAV-3 expression system.
Reddy
P S
PS
Virology group, Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, S7N 5E3, Saskatchewan, Canada.
Idamakanti
N
N
Zakhartchouk
L N
LN
Babiuk
L A
LA
Mehtali
M
M
Tikoo
S K
SK
D017503:Adenovirus E3 Proteins / Q000235:genetics*; D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D002417:Cattle; D002460:Cell Line; D017938:Coronavirus, Bovine / Q000235:genetics*; D017353:Gene Deletion; D005822:Genetic Vectors; D006389:Hemagglutinins, Viral / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D017921:Mastadenovirus / Q000235:genetics*; D011233:Precipitin Tests; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000235:genetics* / Q000378:metabolism
D017503:Adenovirus E3 Proteins; D006389:Hemagglutinins, Viral; D011994:Recombinant Proteins; D014760:Viral Fusion Proteins; C060814:hemagglutinin esterase