Deletion of the African swine fever virus E120R gene completely attenuates its virulence by enhancing host innate immunity and impairing virus release

作者：Bing’e Ma, Yiqian Jiang, Nan Li, Fengjie Wang, Qian Li, Huixian Yue, Yanyan Zhang, Rongliang Hu, Faming Miao · 发表于：Emerging Microbes & Infections · 年份：2025 · DOI：10.1080/22221751.2025.2555722 · 被引用次数：8 · 研究领域：Animal Disease Management and Epidemiology、Vector-Borne Animal Diseases、Viral Infections and Immunology Research

African swine fever virus (ASFV) causes a lethal hemorrhagic disease in domestic pigs and represents a major threat to the global swine industry. Until now, no effective commercial vaccines or antiviral drugs are available for ASF control. In this study, we constructed a recombinant E120R gene-deleted virus, ASFV-ΔE120R, based on the highly virulent genotype II strain SY18, to investigate the biological role of the E120R gene. ASFV-ΔE120R exhibited impaired virion release and formed aberrant tubular structures, rendering viral particles more susceptible to neutralization by convalescent pig sera. RNA sequencing and RT-qPCR analyses revealed that ASFV-ΔE120R infection of porcine alveolar macrophages (PAMs) significantly upregulated the expression of chemokines (CCL5, CCL2, CCL4), interferon-related genes (IRF7, IRF8, ISG15, ISG54, ISG56), and the proinflammatory cytokine IL-1β compared with ASFV-WT. In vivo safety evaluation demonstrated that piglets immunized with a single dose of 5 × 10⁶ TCID₅₀ of ASFV-ΔE120R exhibited no clinical signs of ASF and detectable viral nucleic acid in any organ upon necropsy at days 4, 7, 10, and 14 post-immunization. Notably, even after two rounds of blind cell passage using filtered tissue homogenates, no viral genome was detected. Furthermore, two immunizations at the same dose, administered 21 days apart, did not induce clinical signs or viral shedding during a 28-day observation period. Immunogenicity analysis showed that ASFV-ΔE120R elicite...