Rapid induction and persistence of paracrine-induced cellular antiviral states arrest viral infection spread in A549 cells

- Infection spread occurs over multiple rounds of infection and cell responses.
- Initially, cytokine responses lag significantly behind infection spread.
- Cytokines rapidly disseminate and induce persistent cellular antiviral states.
- Innate antiviral cytokine responses are tightly controlled but ultimately effective.
- Multiple rounds of cell response are necessary for infection arrest.

The virus/host interaction is a complex interplay between pro- and anti-viral factors that ultimately determines the spread or halt of virus infections in tissues. This interplay develops over multiple rounds of infection. The purpose of this study was to determine how cellular-level processes combine to impact the spatial spread of infection. We measured the kinetics of virus replication (VSV), antiviral paracrine signal upregulation and secretion, spatial spread of virus and paracrine antiviral signaling, and inhibition of virus production in antiviral-exposed A549 human lung epithelial cells. We found that initially infected cells released antiviral signals 4-to-7 h following production of virus. However, the subsequent rapid dissemination of signal and fast induction of a robust and persistent antiviral state ultimately led to a suppression of infection spread. This work shows how cellular responses to infection and activation of antiviral responses can integrate to ultimately control infection spread across host cell populations.