Key pig gene for ASF infection discovered

A team of European scientists has found a key pig gene for the replication of African Swine Fever (ASF) virus. Researchers from the Friedrich-Loeffler-Institute (FLI) in Germany and the Roslin Institute of the University of Edinburgh, Scotland, recently conducted this piece of research, which aimed to find out which pig genes are needed for the ASF virus (ASFv) to replicate. The study describing their findings was published in August 2023 in the peer-reviewed scientific journal Scientific Reports and shows that there is a gene from the pig’s immune system that is key to this process. This provides important new insights into the biology of the ASFv that could form the basis for future research approaches. ASFv has a large DNA genome from which more than 160 viral proteins are produced in infected cells. Little is known about the functions of many of these viral proteins. It is also unclear which cellular proteins are used by the ASF virus to enter the host cell. To identify host proteins important for ASFv, scientists at the Roslin Institute provided a CRISPR/Cas9 expression library as a molecular tool that allowed their colleagues Friedrich-Loeffler-Institute to knock out all known genes in the pig genome individually in vitro and test the resulting cell cultures for susceptibility to ASF virus infection. That led to the identification of several genes of the major histocompatibility complex II (MHC II) as relevant factors for the reproductive capacity of ASFv, the news release explained. In particular, the MHC II receptor protein SLA-DM was shown to be required for efficient ASFv infection. Therefore, the research team concluded, SLA-DM may be a suitable target protein for the development of effective therapeutics against ASF or ASFv resistant pig breeds.