African swine fever virus hijacks host pyrimidine metabolism to promote viral replication.

African swine fever (ASF) is a highly contagious disease of pigs caused by the African swine fever virus (ASFV), posing a significant threat to global swine production. As an obligate intracellular parasite, ASFV relies on host metabolic networks to fulfill its replication requirements. However, the precise mechanisms by which it manipulates nucleotide metabolism remain unclear. In this study, untargeted metabolomic analysis of ASFV-infected porcine alveolar macrophages revealed significant perturbations in purine and pyrimidine metabolism, glycolysis, the pentose phosphate pathway (PPP), and the glutamate and aspartate metabolic pathways. Functional validation demonstrated that ASFV depends on de novo pyrimidine biosynthesis for viral genome replication. Notably, ASFV employs a dual strategy to sustain the supply of nucleotide precursors: (i) it hijacks the PPP to generate ribose-5-phosphate and NADPH for redox balance, and (ii) it enhances glutamine uptake and catabolism to provide the nitrogen and carbon needed for nucleotide biosynthesis and tricarboxylic acid cycle replenishment. Furthermore, although aspartate is essential for pyrimidine synthesis, ASFV circumvents dependence on extracellular aspartate by activating a cytosolic GOT1-mediated synthesis pathway. Collectively, these findings elucidate how ASFV reprograms host nucleotide metabolism to support its replication, offering new insights into virus-host metabolic interactions and identifying potential targets for antiviral therapy.IMPORTANCEAfrican swine fever (ASF) is a devastating disease that causes substantial economic losses in the global pig industry. This study demonstrates that the African swine fever virus (ASFV) reprograms host cell metabolism to produce the essential building blocks required for its replication. Specifically, ASFV manipulates host nucleotide biosynthetic pathways to secure both the substrates for DNA synthesis and the reducing power necessary to mitigate oxidative stress. Elucidating these metabolic interactions not only deepens understanding of ASFV pathogenesis but also highlights promising metabolic targets for antiviral therapy. By elucidating how ASFV hijacks nucleotide biosynthesis within infected cells, our findings pave the way for innovative strategies to combat ASF.