Oxygen potentiates antiviral ability of zebrafish in response to SVCV infection

Oxygen (O₂) profoundly influences the physiological processes of aerobic organisms through a range of mechanisms. Recently, increasing evidence has revealed the relationship between viral infection and oxygen levels. However, due to a lack of feasible methods and in vivo models, how oxygen directly affects antiviral capability remains largely unknown. In contrast to terrestrial animals, fish live in water for life, where oxygen levels change more frequently than on land in areas with similar altitude. Therefore, fish appear to be ideal organisms for elucidating the effect of oxygen levels on antiviral responses. In this study, we report that zebrafish under low oxygen conditions are more susceptible to SVCV infection. Further assays indicate that low oxygen tension not only suppresses SVCV-induced IFN activation but also promotes SVCV replication in both zebrafish cell lines and zebrafish. This study provides novel insights into the effect of oxygen on antiviral responses and virus replication.