TLR3 regulates ZIKV replication and secretion of inflammation molecules.

(A) Human astrocytes were infected with ZIKV (MR766, R103451 and PRVABC59) at an MOI of 0.1. After 48 hpi, RNA was extracted from cell lysates and RT-PCR array assays were performed to determine RNA expression of genes involved in the human TLR pathway. A 2-fold change in gene expression was used as the cut-off value. (B-D) Detection of TLR3, TLR4 and TLR5 expression levels by western blot after 48 hpi. (E) Protein expression levels of the TLR adaptor protein MyD88 after infection with ZIKV-PRVABC59. (F-J) Human astrocytes were infected with three different strains of ZIKV (MR766, R103451 and PRVABC59) at an MOI of 0.1. Sets of experiment included astrocytes treated with 5μg/mL of Poly I: C (TLR3 agonist), or with TLR3 silenced with siRNA or inhibited with a thiophenecarboxamidopropionate compound (TLR3/dsRNA complex inhibitor). After 48 hpi, RNA was extracted from the supernatant and RT-PCR using ZIKV specific primers was performed to determine viral titers (F). Cell supernatants were used to perform ELISA to detect levels of IL-6, RANTES and IFN-β (G-J). Mock (PBS) infected human astrocytes were used as the control. Data are presented as the mean ± SEM from 3 independent experiments. (*p# p<0.05 Vs ZIKV alone).