Porcine reproductive and respiratory syndrome (PRRS), which is caused by the porcine reproductive and respiratory syndrome virus (PRRSV), results in substantial economic losses for the global pig farming industry. A critical step in the infection process is the binding of PRRSV to the CD163 receptor on the surface of porcine alveolar macrophages. This study successfully generated CD163−/− Landrace pigs using CRISPR/Cas9 gene editing technology. Following an experimental challenge with two distinct Type II PRRSV strains, the edited pigs exhibited complete resistance to infection. Virological and pathological examinations confirmed the absence of viral replication and the presence of characteristic pulmonary lesions and other organ damage in CD163−/− pigs. In contrast, wild-type control pigs exhibited high viral loads and severe pulmonary lesions, as well as damage to other organs. Our findings provide direct evidence that CD163 is an essential receptor for PRRSV infection in vivo. The CD163−/− pig model offers an effective genetic strategy for breeding pigs with an inherent resistance to PRRSV.
Wu et al. (Mon,) studied this question.