Quantitative proteomic analysis identifies the unfolded protein response as a host pathway co-opted by ASFV to promote replication

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a highly contagious disease that affects pigs, resulting in substantial economic losses in the global pig industry. A comprehensive understanding of viral-host protein interactions can facilitate the discovery of therapies for viral infection. In this study, we employ a 4D label-free quantitative proteomics approach to profile a comprehensive protein dynamics analysis in ASFV-infected pigs, identifying over 6,000 proteins across multiple organs. Our results reveal coordinated interorgan responses characterized by inflammatory activation and interferon signaling in defense against ASFV. The protein-protein interaction network analysis uncovers ASFV-induced functional modules, including the unfolded protein response (UPR), innate immune signaling, and inflammation, which are conserved across tissues. Notably, ASFV robustly activates all three branches of the UPR both <i>in vivo</i> and <i>in vitro</i> to promote viral replication. Furthermore, we identify that the virus-encoded protein D117L interacts with multiple UPR-related host proteins, thereby directly triggering UPR activation. Collectively, this study delineates the organ-specific proteomic landscape of ASFV infection, providing valuable insights into virus-host interactions and offering potential therapeutic targets for ASF.IMPORTANCEAfrican swine fever virus (ASFV) has caused severe consequences for the global pig industry. In this study, we conducted a multi-organ proteomic analysis using a 4D label-free quantitative proteomics approach and mapped the organ-specific proteomic landscape during ASFV infection. This work overcomes the limitations of most existing studies, which are primarily restricted to <i>in vitro</i> cell models and provide a more comprehensive understanding of ASFV infection and pathogenesis. Notably, the viral D117L protein is identified as a critical modulator of host cellular responses, directly subverting the unfolded protein response (UPR) pathway through specific interactions with host UPR-associated proteins. Collectively, our work lays the foundation for understanding the pathogenesis of ASFV, providing potential therapeutic strategies against African swine fever.