The L83L ORF of African swine fever virus strain Georgia encodes for a non-essential gene that interacts with host protein IL-1ß

Authors: Borca, Manuel; O'DONNELL, VIVIAN - Animal And Plant Health Inspection Service (APHIS); Holinka-Patterson, Lauren; RAMIREZ, ELIZABETH - Oak Ridge Institute For Science And Education (ORISE); VUONO, ELIZABETH - Oak Ridge Institute For Science And Education (ORISE); BERGGREN, KEITH - Oak Ridge Institute For Science And Education (ORISE); ALFANO, MARIALEXIA - Oak Ridge Institute For Science And Education (ORISE); CAREY, LUCAS - Pompeu Fabra University; RICHT, JUERGEN - Kansas State University; RISATTI, GUILLERMO - University Of Connecticut; Gladue, Douglas

Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2018
Publication Date: 3/29/2018
Citation: Borca, M.V., O'Donnell, V., Holinka-Patterson, L.G., Ramirez, E., Vuono, E., Berggren, K., Alfano, M., Carey, L.B., Richt, J.A., Risatti, G.R., Gladue, D.P. 2018. The L83L ORF of African swine fever virus strain Georgia encodes for a non-essential gene that interacts with host protein IL-1ß. Virus Research. 249:116-123. https://doi.org/10.1016/j.virusres.2018.03.017.
DOI: https://doi.org/10.1016/j.virusres.2018.03.017

Interpretive Summary: African swine fever has many different genes. Very few of these genes have been studied and the function remains largely unknown. We take some of these unknown proteins and with bioinformatics predict its potential function. We then discovered the cellular proteins that bind to these viral proteins. We found that one of the viral proteins binds a cellular protein that is expressed in animals as a method for fighting viruses, this cellular protein is called, Interleukin-1-Beta. However, when we deleted the viral protein there was no effect on the virus, and disease still occurred. This tells us that this viral protein is not required for the virus to cause disease.

Technical Abstract: African swine fever virus (ASFV) causes a contagious and frequently lethal disease of pigs that produces significant economic consequences to the swine industry. ASFV genome encodes for more than 150 genes, but only a few of them have been studied in detail. Here we report the characterization of open reading frame (ORF) L83L. A recombinant ASFV harboring a HA tagged version of the L83L protein was developed (ASFV-G-L83L-HA) and used to demonstrate that L83L is a transiently expressed early virus protein. An ASFV recombinant virus having deleted the L83L gene (ASFV-G-DeltaL83L) was developed from the highly virulent field isolate Georgia2007 (ASFV-G) indicating that L83L is a non-essential gene. ASFV-G-deltaL83L was showed to have a similar ability to replicate in primary swine macrophage cell cultures when compared to its parental virus ASFV-G. Analysis of host-protein interactions for L83L using a yeast two-hybrid screen, identified IL-1Beta as its host ligand. Experimental infection of domestic pigs through the intranasal or intramuscular route showed that ASFV-G-deltaL83L is as virulent as the parental virus ASFV-G.