Deletion of the ASFV dUTPase gene E165R from the genome of highly virulent African swine fever virus Georgia 2010 does not affect virus replication or virulence in domestic pigs

Authors: VUONO, ELIZABETH - US Department Of Agriculture (USDA); Ramirez-Medina, Elizabeth; Pruitt, Sarah; RAI, AYUSHI - Oak Ridge Institute For Science And Education (ORISE); Espinoza, Nallely; Silva, Ediane; Velazquez, Lauro; Gladue, Douglas; Borca, Manuel

Submitted to: Viruses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2022
Publication Date: 6/28/2022
Citation: Vuono, E., Ramirez Medina, E., Pruitt, S.E., Rai, A., Espinoza, N.N., Silva, E.B., Velazquez Salinas, L., Gladue, D.P., Borca, M.V. 2022. Deletion of the ASFV dUTPase gene E165R from the genome of highly virulent African swine fever virus Georgia 2010 does not affect virus replication or virulence in domestic pigs. Viruses. 14(7):1409. https://doi.org/10.3390/v14071409.
DOI: https://doi.org/10.3390/v14071409

Interpretive Summary: African swine fever virus (ASFV) causes a devastating disease in swine, called African swine fever (ASF), that is currently spreading across Europe, Asia and recently appeared in the Americas. Here we report on the function of a new gene in ASF where deletion of that gene is not necessary for the virus to replicate in cell cultures or to cause disease in swine.

Technical Abstract: African swine fever (ASF) is a frequently lethal disease of domestic and wild swine currently producing a pandemic affecting pig production in Eurasia. The causative agent, ASF virus (ASFV) is a structurally complex virus with a large genome harboring over 150 genes. One of them, E165R, encodes for a protein belonging to the dUTPase family. The fine structure of the purified protein has been recently analyzed and its dUTPase activity tested. In addition, it has been reported that a BA71 mutant virus, adapted to growth in Vero cells, lacking the E165R gene presented a drastic decreased replication in swine macrophages, its natural target cell. Herein, we report the development of a recombinant virus, ASFV-G-E165R, harboring the deletion of the E165R gene from the genome of the highly virulent field isolate ASFV Georgia 2010 (ASFV-G). Interestingly, ASFV-G-E165R replicates in primary swine macrophage cultures as efficiently as the parental virus ASFV-G. In addition, ASFV-G-E165R also replicates in experimentally inoculated domestic pigs with equal efficacy as ASFV-G and produced a lethal disease almost indistinguishable from that induced by the parental virus. Therefore, results presented here clearly demonstrated that E165R gene is not essential or important for ASFV replication in swine macrophages nor disease production in domestic pigs.