The Accumulation of Phenyllactic Acid Impairs Host Glutamine Metabolism and Inhibits African Swine Fever Virus Replication: A Novel Target for the Development of Anti-ASFV Drugs.

African swine fever (ASF) is a highly contagious and hemorrhagic disease caused by infection with the African swine fever virus (ASFV), resulting in a mortality rate of up to 100%. Currently, there are no effective treatments and commercially available vaccines for ASF. Therefore, it is crucial to identify biochemicals derived from host cells that can impede ASFV replication, with the aim of preventing and controlling ASF. The ASFV is an acellular organism that promotes self-replication by hijacking the metabolic machinery and biochemical resources of host cells. ASFV specifically alters the utilization of glucose and glutamine, which are the primary metabolic sources in mammalian cells. This study aimed to investigate the impact of glucose and glutamine metabolic dynamics on the rate of ASFV replication. Our findings demonstrate that ASFV infection favors using glutamine as a metabolic fuel to facilitate self-replication. ASFV replication can be substantially inhibited by blocking glutamine metabolism. The metabolomics analysis of the host cell after late-stage ASFV infection revealed a significant disruption of normal glutamine metabolic pathways due to the abundant expression of PLA (phenyllactic acid). Pretreatment with PLA also inhibited ASFV proliferation and glutamine consumption following infection. The metabolomic analysis also showed that PLA pretreatment greatly slowed down the metabolism of amino acids and nucleotides that depend on glutamine. The depletion of these building blocks directly hindered the replication of ASFV by decreasing the biosynthetic precursors produced during the replication of ASFV's progeny virus. These findings provide valuable insight into the possibility of pursuing the development of antiviral drugs against ASFV that selectively target metabolic pathways.