title: Expression of bovine interleukin-1 beta in a bovine herpesvirus-1 vector: in vitro analysis.
abstract: In order to evaluate whether bovine herpesvirus-1 (BHV-1) could be used as a live viral vector for the expression of cytokines, we constructed a recombinant BHV-1 expressing bovine interleukin-1 beta (boIL-1 beta). The boIL-1 beta coding sequence, corresponding to the cleaved mature product, was fused with the BHV-1 glycoprotein C (gC) signal peptide sequence; the resultant gC-boIL-1 beta fusion gene was recombined into the gC locus of the BHV-1 genome. Southern blot analysis confirmed the proper genomic configuration of the recombinant virus. Results from transcript analysis showed that boIL-1 beta was expressed in infected cells with kinetics similar to that of gC. Indirect immunofluorescence and immunoprecipitation assays showed that the recombinant protein was produced in both cell-associated and secreted forms. Western blot analysis detected a 19.3-kDa protein. Further analysis, using an IL-1 beta bioassay demonstrated that both the cellular and secreted forms of recombinant boIL-1 beta possessed biological activity. The expression of the boIL-1 beta protein did not affect the in vitro growth efficiency of the virus, which exhibited similar growth kinetics to that of a simple gC deletion mutant. The results from this study demonstrate that BHV-1 can be used to express a functional cytokine, thereby establishing the basis to further study recombinant BHV-1 expressing cytokines as an alternative means to attenuate the virus and also as a potential in situ cytokine delivery system to modulate immune responses against BHV-1 and other cattle pathogens.
authors.affiliation: Department of Veterinary Microbiology, University of Saskatchewan, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Raggo
authors.forename: D R
authors.initials: DR
authors.lastname: Fitzpatrick
authors.forename: L A
authors.initials: LA
authors.lastname: Babiuk
authors.forename: X
authors.initials: X
authors.lastname: Liang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002460:Cell Line; D003001:Cloning, Molecular; D004279:DNA, Viral; D015870:Gene Expression; D005822:Genetic Vectors; D007242:Herpesvirus 1, Bovine / Q000235:genetics* / Q000254:growth & development; D007375:Interleukin-1 / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000032:analysis; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D004279:DNA, Viral; D007375:Interleukin-1; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins