Efficiencies and kinetics of infection in different cell types/lines by African and Asian strains of Zika virus

After recent outbreaks, Zika virus (ZIKV) was linked to severe neurological diseases including Guillain-Barre syndrome in adults and microcephaly in newborns. The severities of pathological manifestations have been associated with different ZIKV strains. To better understand the tropism of ZIKV, we infected 10 human and four nonhuman cell lines (types) with two African (IbH30656 and MR766) and two Asian (PRVABC59 and H/FP/2013) ZIKV strains. Cell susceptibility to ZIKV infection was determined by examining viral titers, synthesis of viral proteins, and replication of positive and negative strands of viral genome. Among nonhuman cell lines, only Vero cells were efficiently infected by ZIKV. Among human cell lines, all were permissive to ZIKV infection. However, 293T and HeLa cells showed differential susceptibility towards African strains. In 293T cells, the NS1 protein was expressed at the high level by African strains but was almost not expressed by Asian strains though there was no obvious difference in viral genome replication, suggesting that the differential susceptibility might be controlled at the stage of viral protein translation. This study provides comprehensive results of the permissiveness of different cell types to both African and Asian ZIKV strains, which might help clarify their different pathogenesis.