Establishment of Humanized <i>EFNB2/B3</i> Murine Models for Investigating Nipah Virus Pathogenesis

ABSTRACT Nipah virus (NiV) is a zoonotic paramyxovirus classified as a WHO priority pathogen, which causes severe respiratory disease and encephalitis in humans with high mortality. Currently, no licensed vaccines or specific antiviral therapies are available. A major obstacle in NiV research is the lack of immunocompetent rodent models that endogenously express human‐compatible entry receptors Ephrin‐B2 (EFNB2) and Ephrin‐B3 (EFNB3). Here, we report the generation and characterization of two novel knock‐in mouse models using the CRISPR/Cas9 system. The human EFNB2 or EFNB3 gene, driven by the human keratin 18 (K18) promoter, was site‐specifically integrated into the mouse Hipp11 ( H11 ) safe‐harbor locus. Founder mice exhibited stable germline transmission without obvious developmental abnormalities. These established models provide a physiologically relevant and genetically engineered platform for studying NiV entry mechanisms, pathogenesis, and the development of vaccines and antiviral therapeutics.