Interference of dengue replication by blocking the access of 3 ´ SL RNA to the viral RNA-dependent RNA polymerase.

Interference of dengue replication by blocking the access of 3´ SL RNA to the viral RNA-dependent RNA polymerase. Antiviral Res. 2020 Aug 21;:104921 Authors: Tunghirun C, Narkthong V, Chaicumpa W, Chimnaronk S Abstract The four circulating serotypes of dengue virus (DENV) occasionally cause potentially fetal symptoms of severe dengue, which there is currently no specific treatment available. Extensive efforts have been made to inhibit viral replication processes by impeding the activity of an exclusive RNA-dependent RNA polymerase (RdRp) in the viral non-structural protein 5 (NS5). In our earlier work, we identified the characteristic, specific interaction between the C-terminal thumb subdomain of RdRp and an apical loop in the 3´ stem-loop (SL) element in the DENV RNA genome, which is fundamental for viral replication. Here, we demonstrated a new approach for interfering viral replication via blocking of 3´ SL RNA binding to RdRp by the single-chain variable fragments (scFvs). We isolated and cloned 3 different human scFvs that bound to RdRp from DENV serotype 2 and interfered with 3´ SL-binding, utilizing a combination of phage-display panning and Alpha methods. When tagged with a cell penetrating peptide, a selected scFv clone, 2E3, entered cells and colocalized with NS5 in cytoplasm of infected HuH-7 cells. 2E3 significantly inhibited DENV RNA replication with sub-nanomolar EC50 values and significantly reduced production of ...
Source: Antiviral Research - Category: Virology Authors: Tags: Antiviral Res Source Type: research