Development of a lethal adult mouse model of Coxsackievirus B1 infection for antiviral research.

Coxsackievirus B1 (CVB1), a clinically significant human enterovirus, causes a wide spectrum of diseases ranging from mild illness to severe, life-threatening conditions in susceptible individuals. However, investigations into CVB1 infection pathogenesis, as well as the development and evaluation of antiviral strategies, have long been constrained by the lack of immunocompetent animal models that recapitulate human CVB1 infections. In this study, we established a lethal CVB1 infection model in immunocompetent adult BALB/c mice. Using a reverse genetics approach, we generated the CVB1-XM0108 virus from a clinical isolate and infected adult BALB/c mice. Our results demonstrated that this virus exhibited a strong tropism for the pancreas, liver, and skeletal muscles, leading to extensive inflammation in these organs. Passive immunization with anti-CVB1 serum dose-dependently reduced viral replication, tissue damage, weight loss, and mortality. This pathologically relevant mouse model provides a valuable platform for advancing CVB1 therapeutic and vaccine development.