Establishment of a highly sensitive porcine alveolar macrophage cell line for African swine fever virus.

Abstract

African swine fever (ASF) caused by the African swine fever virus (ASFV) is a significant threat to domestic pig populations because of its highly contagious nature and associated morbidity and mortality. The lack of an appropriate cell line for ASFV propagation has significantly hindered the development of a safe and effective vaccine. In this study, we aimed to identify a cell line that is highly receptive to ASFV by evaluating various genes to determine their ability to support ASFV infection and replication. Our investigation revealed the efficient infection of a porcine alveolar macrophage cell line iPAM, upon stable overexpression of the transmembrane protein 107 (TMEM107). An isolated monoclonal cell line iPAM^{pCDH-TMEM107-B6} that was derived from the parental iPAM cell line exhibited increased susceptibility to ASFV infection. Notably, iPAM^{pCDH-TMEM107-B6} cells concurrently expressed ASFV B646L and ASFV p30 proteins after infection with ASFV. Biological characterization of iPAM^{pCDH-TMEM107-B6} revealed an enhanced proliferative capacity without compromised phagocytic function, indicating the retention of key cellular traits following genetic modification. The iPAM^{pCDH-TMEM107-B6} cell line has significant potential for ASFV research and will facilitate tasks such as isolation, replication, and genetic manipulation. The establishment of ASFV-sensitive cell lines provides an in vitro research platform for ASFV investigations, thereby advancing our understanding of the pathogenic mechanisms and aiding in vaccine development efforts.