Efficient heterologous antigen gene delivery and expression by a replication-attenuated BoHV-4-based vaccine vector

作者：Capocefalo Antonio; Mangia Carlo; Franceschi Valentina; Jacca Sarah; van Santen Vicky L; Donofrio Gaetano^*

来源：Vaccine, 2013, 31(37): 3906-3914.

DOI：10.1016/j.vaccine.2013.06.052

• Bovine herpesvirus 4
• Recombinant virus
• Gene deletion
• Non-coding RNA
• Viral vector

Bovine Herpesvirus 4 (BoHV-4) is a gammaherpesvirus belonging to the Rhadinovirus genus and due to its biological characteristics has been proposed as a vaccine vector for veterinary vaccines. Because viral vector-associated risk is a major concern for viral vector applications, attenuation is a desirable feature. Therefore, efforts are directed toward the development of highly attenuated viral vectors. BoHV-4 naturally exhibits limited pathogenicity and a further attenuation, in terms of replication, was obtained by disrupting the late gene encoding the 1.7-kb polyadenylated RNA (L1.7). An L1.7 deleted mutant BoHV-4 (BoHV-4-A-KanaGaIK Delta L1.7), as well as its revertant (BoHV-4-A-Rev), was generated by homologous recombination from the genome of a BoHV-4 isolate (BoHV-4-A) cloned as a bacterial artificial chromosome (BAC). BoHV-4-A-KanaGaIK Delta L1.7 showed attenuation in terms of competence to reconstitute infectious virus, viral replication, and plaque size when compared to BoHV-4-A, BowHV-4-A-Rev, and BoHV-4-A-KanaGalK Delta TK, a recombinant control virus where the KanaGalK selectable marker was inserted into the thymidine kinase open reading frame. The capability of BoHV-4-A-KanaGalK Delta L1.7 to deliver and express a heterologous antigen was investigated by replacing the KanaGalK cassette with a vesicular stomatitis virus glycoprotein (VSVg) expression cassette to generate BoHV-4A-EF1 alpha VSVg Delta L1.7. BoHV-4-A-EF1 alpha NSVg Delta L1.7 infected cells robustly expressed VSVg, thus confirming that the replication deficiency resulting from L1.7 disruption did not prevent heterologous gene delivery and expression. Although further work is needed to identify the specific function of the BoHV-4 L1.7 gene, the L1.7 gene may represent an ideal targeting locus for the integration of a heterologous antigen expression cassette, resulting in attenuation of the viral vector.

• 出版日期2013-8-20