Mapping in toto immune cell dynamics during viral infection in zebrafish

Our bodies are known to harbor hundreds of trillions of viruses. Despite the large number and diversity, the interactions of these viruses with our immune system remains to be well characterized, particularly in the context of infection. To map the dynamics of various immune cells upon viral infection in toto, we employ larval zebrafish as a model system given its transparency, small size, and genetic tractability. Combining a transgenic zebrafish with a reporter for interferon stimulated gene 15 (isg15), a signature of antiviral activity and markers for various immune cells such as macrophages and neutrophils, we perform high resolution live imaging of zebrafish to map spatiotemporal dynamics of immune cells as well as antiviral expression in the whole organism upon infection Zebrafish Picornavirus (ZfPV). ZFPV is a single stranded RNA virus, isolated from zebrafish, that is known to infect and stimulate isg15 expression in the intestine. Through tracking of individual immune cells in infected fish, we identify key immune players and characterize their dynamics during infection. The findings from this study will reveal novel first insights into viral infection dynamics in a vertebrate organism.