African Swine Fever Virus (ASFV) is a large, icosahedral DNA virus that causes African Swine Fever (ASF), a highly contagious and often lethal disease affecting domestic and wild pigs. This disease poses a significant threat to the global swine industry due to its high mortality rate and lack of effective vaccines or treatments. The ASFV genome contains multiple multigene families (MGFs), which play crucial roles in viral replication, virulence, and host interaction. Among these, the MGF 110 family, particularly the MGF 110-9L gene, has been identified as a virulence factor involved in modulating the host immune response.
The MGF 110-9L gene is part of the ASFV MGF 110 family, located at the left end of the ASFV genome. It encodes a protein with a hydrophobic NH2-terminal sequence and a conserved cysteine-rich domain, which may be involved in viral morphogenesis and host range determination . The deletion of MGF 110-9L from ASFV results in a partially attenuated virus, which can induce a strong virus-specific antibody response in pigs and enhance their survival rates compared to the parental virus .
MGF 110-9L is known to inhibit type I interferon (IFN) production, which is crucial for the host's innate immune response against viral infections . The deletion of this gene enhances type I IFN production, potentially contributing to the attenuation of the virus . Additionally, MGF 110-9L may regulate multiple host functions, including the Toll signaling pathway and apoptosis .