A Fluorescent Cell-Based System for Imaging Zika Virus Infection in Real-Time.

Zika virus (ZIKV) is a re-emerging flavivirus that is transmitted to humans through the bite of an infected mosquito or through sexual contact with an infected partner. ZIKV infection during pregnancy has been associated with numerous fetal abnormalities, including prenatal lethality and microcephaly. However, until recent outbreaks in the Americas, ZIKV has been relatively understudied, and therefore the biology and pathogenesis of ZIKV infection remain incompletely understood. Better methods to study ZIKV infection in live cells could enhance our understanding of the biology of ZIKV and the mechanisms by which ZIKV contributes to fetal abnormalities. To this end, we developed a fluorescent cell-based reporter system allowing for live imaging of ZIKV-infected cells. This system utilizes the protease activity of the ZIKV non-structural proteins 2B and 3 (NS2B-NS3) to specifically mark virus-infected cells. Here, we demonstrate the utility of this fluorescent reporter for identifying cells infected by ZIKV strains of two lineages. Further, we use this system to determine that apoptosis is induced in cells directly infected with ZIKV in a cell-autonomous manner. Ultimately, approaches that can directly track ZIKV-infected cells at the single cell-level have the potential to yield new insights into the host-pathogen interactions that regulate ZIKV infection and pathogenesis.