The transcriptome of the parapoxvirus Orf virus reveals novel promoters for heterologous gene expression by poxvirus vectors

Lok R Joshi; Gabriela Mansano do Nascimento; Diego G Diel

doi:10.1016/j.virol.2023.109864

The transcriptome of the parapoxvirus Orf virus reveals novel promoters for heterologous gene expression by poxvirus vectors

Virology. 2023 Oct:587:109864. doi: 10.1016/j.virol.2023.109864. Epub 2023 Aug 6.

Authors

Lok R Joshi¹, Gabriela Mansano do Nascimento¹, Diego G Diel²

Affiliations

¹ Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, USA.
² Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, USA. Electronic address: dgdiel@cornell.edu.

PMID: 37595395
DOI: 10.1016/j.virol.2023.109864

Abstract

Orf virus (ORFV) has been used as a vaccine delivery vector for multiple animal species. Several strategies are being used to improve the immunogenicity and efficacy of ORFV vectors, including the use of poxviral promoter(s) with strong early and late activity capable of driving the expression of the heterologous genes for a prolonged time and eliciting a potent immune response. Here, we used RNA-sequencing (RNA-Seq) approach to analyze the transcriptome of ORFV during infection in primary ovine cells. Based on the transcriptional profile of individual ORFV genes, we identified ORFV promoters with strong early and late activity and have shown that they can be used to express heterologous genes in ORFV vectors. Our results show that the intergenic regulatory sequence containing core promoter sequences present upstream of ORF112 (p112) and ORF116 (p116) lead to markedly higher transgene expression than conventional poxviral promoters. Thus, these promoters are valuable alternatives to express transgenes in poxviral vectors.

Keywords: Orf virus; Poxvirus; Promoter; RNA-Seq; Transcriptome.