ZIKV replication is differential in explants and cells of human placental which is suppressed by HSV-2 coinfection

Abstract

During the Zika fever outbreak in Brazil in 2015-2016, only some babies from infected mothers had teratogenic effects, suggesting that cofactors may influence congenital transmission. We investigated the ZIKV infection profile in explants and isolated cells from full-term human placenta to infection with the Brazilian Zika virus strain (ZIKV^BR) and the effect of coinfection with the Brazilian Human alphaherpesvirus 2 strain (HSV-2^BR) on ZIKV replication. We found that the ZIKV^BR infect the explants of amniotic and chorionic membranes, as well as chorionic villi core, but not the trophoblasts layer. It was also observed that ZIKV replication was higher in amniotic cells than chorionic and trophoblasts cells. Upon coinfection, the replication of ZIKV^BR was reduced according to exposed HSV-2^BR load in trophoblasts cells and the levels of TNF-α and IL-6 cytokines were also reduced. These findings suggest that the placental cell types and HSV-2^BR coinfection may impact on ZIKV replication.

Keywords: Coinfection; Congenital transmission; Cytokine; HHV-2(BR); Placental susceptibility; ZIKV(BR).