Autocrine and paracrine interferon signaling as 'ring vaccination' and 'contact tracing' strategies to suppress virus infection in a host

Lavigne, G. M.; Russell, H.; Sherry, B.; Ke, R.

The innate immune response, particularly the interferon response, represents a first line of defense against viral infections. The interferon molecules produced from infected cells act through autocrine and paracrine signaling to turn host cells into an antiviral state. Although the molecular mechanisms of IFN signaling have been well characterized, how the interferon response collectively contribute to the regulation of host cells to stop or suppress viral infection during early infection remain unclear. Here, we use mathematical models to delineate the roles of the autocrine and the paracrine signaling, and show that their impacts on viral spread are dependent on how infection proceeds. In particular, we found that when infection is well-mixed, the paracrine signaling is not as effective; in contrast, when infection spreads in a spatial manner, a likely scenario during initial infection in tissue, the paracrine signaling can impede the spread of infection by decreasing the number of susceptible cells close to the site of infection. Furthermore, we argue that the interferon response can be seen as a parallel to population-level epidemic prevention strategies such as contact tracing or ring vaccination. Thus, our results here may have implications for the outbreak control at the population scale more broadly.