RESUMEN
BACKGROUND: African swine fever (ASF) is a viral disease that affects pigs and wild boars providing economic burden in swine industry. METHODS AND RESULTS: In this study, we investigated the effect of deleting the ASFV multigene family 110 (MGF110) fragment (1 L-5-6 L) on apoptosis modulation and the expression of proinflammatory cytokines. Gene expression in swine peripheral blood macrophages infected with either the parental "Volgograd/14c" strain or the gene-deleted "Volgograd/D(1L-5-6L) MGF110" strain was analyzed. Caspase-3 activity was 1.15 times higher in macrophages infected with the parental ASFV strain compared to the gene-deleted strain. Gene expression analysis of Caspase-3 (Cas-3), Interferon-A (IFN-A), Tumor Necrosis Factor A (TNF-A), B-cell Lymphoma-2 (Bcl-2), Nuclear Factor Kappa B (NF-kB), Interleukin-12 (IL-12), and Heat Shock Protein-70 (HSP-70) using RT-qPCR at various time points after infection revealed significant differences in expression profiles between the strains. The peak expression of cytokines (except NF-kB) occurred at 24 h post-infection with the "Volgograd/D(1L-5-6L) MGF110" strain. In samples infected with the ASFV "Volgograd/14c" strain, the most intense expression was observed at 72 and 96 h, except for Bcl-2 and NF-kB, which peaked at 6 h post-infection. The cytokine expression trend for the "Volgograd/D(1L-5-6L) MGF110" strain was more stable with higher expression values. CONCLUSION: The expression trend for the parental strain increased over time, reaching maximum values at 72 and 96 h post-infection, but the overall expression level was lower than that of the gene-deleted strain. These findings suggest that deleting the multigene family 110 members (1 L-5-6 L) contributes to ASFV attenuation without affecting virus replication kinetics.