Highly suitable LFBK cells for African swine fever virus replication and type I interferon-induced immune studies

African swine fever virus (ASFV), the causative agent of African swine fever, is a fatal haemorrhagic virus affecting domestic pigs and wild boars. The primary target cells for ASFV infection are porcine alveolar macrophages (PAMs); however, PAM isolation and maintenance are technically challenging, and genetic manipulation of these cells is difficult. The lack of suitable cell lines that support ASFV infection and replication has significantly hindered vaccine development. This study aimed to overcome these limitations and advance ASFV research. The results demonstrate that the foetal porcine kidney cells (LFBK) are suitable for ASFV studies. We observed that ASFV replicated significantly more efficiently in LFBK cells than in PAMs. Furthermore, LFBK cells exhibited antiviral immune responses similar to PAMs following ASFV infection or DNA analog. These findings suggest that the LFBK cell line could provide a much-needed platform for studying ASFV replication and pathogenesis while serving as a valuable tool for understanding ASFV-induced immune mechanisms.