Evaluation in Swine of a Recombinant African Swine Fever Virus Lacking the MGF-360-1L Gene

• Main Authors: Elizabeth Ramirez-Medina, Elizabeth A. Vuono, Ayushi Rai, Sarah Pruitt, Ediane Silva, Lauro Velazquez-Salinas, James Zhu, Douglas P. Gladue, Manuel V. Borca
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Viruses
• Subjects: ASFV; ASF; African swine fever virus; MGF360-1L
• Online Access: https://www.mdpi.com/1999-4915/12/10/1193

The African swine fever (ASF) pandemic is currently affecting pigs throughout Eurasia, resulting in significant swine production losses. The causative agent, ASF virus (ASFV), is a large, structurally complex virus with a genome encoding more than 160 genes. The function of most of those genes remains unknown. Here, we presented the previously uncharacterized ASFV gene MGF360-1L, the first gene in the genome. The kinetic studies of virus RNA transcription demonstrated that the MGF360-1L gene was transcribed as a late virus protein. The essentiality of MGF360-1L to virus replication was evaluated by developing a recombinant ASFV lacking the gene (ASFV-G-ΔMGF360-1L). In primary swine macrophage cell cultures, ASFV-G-ΔMGF360-1L showed similar replication kinetics as the parental highly virulent field isolate Georgia2007 (ASFV-G). Domestic pigs experimentally infected with ASFV-G-ΔMGF360-1L presented with a clinical disease indistinguishable from that caused by ASFV-G, demonstrating that MGF360-1L was not involved in virulence in swine, the natural host of ASFV.