Characterization of the infectivity of an Indonesian Zika virus strain in mammalian cell lines

Objective: To characterize the infection patterns and growth characteristics of the Zika virus (ZIKV) strain JMB-185 from Indonesia in various mammalian cell lines. Methods: ZIKV was grown in human (A549, HEK293, HepG2, Huh7, Jurkat, and THP-1) and non-human mammalian (RAW264.7, Vero, and Vero76) cell lines. Viral replication kinetics were measured using plaque assay, while intra- and extracellular viral RNA concentrations were assessed using RT-PCR. Flow cytometry was used to quantify the infected cells and cell viability was measured using an MTT assay. The ability of ZIKV to infect cell lines was visualized using a fluorescence immunostaining assay. Results: This ZIKV strain preferentially infected the lung, kidney, and liver cell lines A549, HEK293, Huh7, Vero, and Vero76, but not the immune cells Jurkat, RAW264.7, and THP-1. By contrast, the ZIKV showed no sign of infection in HepG2 cells, while maintaining viral titer over 3 days post-infection, with no infection recorded in immunostaining, no increase in viral RNA, and no indication of cell deterioration. Conclusions: The Indonesian ZIKV strain has a similar infection profile as other strains, except for its poor infectivity on HepG2 cells. Information on the growth characteristics of Indonesia ZIKV will help expand our understanding of the biology of ZIKV which will be useful for various applications including antiviral discovery.