Cd36 deficiency enhances the immune defence against Grass Carp Reovirus in zebrafish

CD36, a single-chain transmembrane glycoprotein belonging to the class B scavenger receptor family, remains enigmatic in terms of its antiviral immune function, with some conflicting conclusions. This study aims to elucidate the role of Cd36 in antiviral immunity using zebrafish as a model organism. We generated cd36^-/- zebrafish mutants using CRISPR/Cas9 technology and challenged them with Grass Carp Reovirus (GCRV), a dsRNA virus. Compared to wild-type (WT) zebrafish, cd36^-/- zebrafish exhibited stronger antiviral immunity, reduced viral load, and lower mortality. Transcriptome sequencing analysis of liver tissue revealed that the differentially expressed genes (DEGs) between WT and cd36^-/- zebrafish were primarily enriched in metabolic pathways, such as glycan biosynthesis and fatty acid metabolism. This suggests that Cd36 may modulate antiviral immune responses by influencing metabolic activities. Our findings provide a foundation for further investigations into the functional and molecular mechanisms of Cd36 in antiviral immunity in fish.