The C962R ORF of African swine fever strain Georgia is non-essential and not required for virulence in swine

Authors: RAMIREZ-MEDINA, ELIZABETH - University Of Connecticut; VUONO, ELIZABETH - University Of Mississippi; PRUITT, SARAH - Oak Ridge Institute For Science And Education (ORISE); RAI, AYUSHI - Oak Ridge Institute For Science And Education (ORISE); SILVA, EDIANE - University Of Kansas; Zhu, James; VELAZQUEZ-SALINAS, LAURO - University Of Kansas; Gladue, Douglas; Borca, Manuel

Submitted to: Viruses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2020
Publication Date: 6/23/2020
Citation: Ramirez-Medina, E., Vuono, E.A., Pruitt, S., Rai, A., Silva, E., Zhu, J.J., Velazquez-Salinas, L., Gladue, D.P., Borca, M.V. 2020. The C962R ORF of African swine fever strain Georgia is non-essential and not required for virulence in swine. Viruses. https://doi.org/10.3390/v12060676.
DOI: https://doi.org/10.3390/v12060676

Interpretive Summary: African swine fever virus (ASFV) causes a devastating disease in swine, called African swine fever (ASF), that is currently spreading across Europe and Asia. There is no available vaccine for ASF, and currently only experimental live attenuated vaccines are derived from deletions of individual genes in the ASFV genome. In this study we a delete a gene in ASFV, that that has never been deleted before and did not alter the pathogenesis of ASFV. We identified two cellular proteins that bind this gene giving insight into how ASFV interacts with cells.

Technical Abstract: African swine fever virus (ASFV) is the causative agent of the African swine fever (ASF) epizootic currently affecting pigs throughout Eurasia, causing significant economic losses in the swine industry. The virus genome encodes for more than 160 genes, of which only a few have been studied in detail. Here we describe the previously uncharacterized ASFV open reading frame (ORF) C962R, a gene encoding for a putative NTPase. RNA transcription studies using infected swine macrophages demonstrated that the C962R gene is translated as a late virus protein. A recombinant ASFV lacking the C962R gene (ASFV-G-'C962R) demonstrated in vivo that the C962R gene is non-essential, since ASFV-G-'C962R had similar replication kinetics in primary swine macrophage cell cultures when compared to parental highly virulent field isolate Georgia2007 (ASFV-G). Experimental infection of domestic pigs with ASFV-G-'C962R produced a clinical disease similar to that caused by the parental ASFV-G, confirming that deletion of the C962R gene from the ASFV genome does not impact virulence.