Cross-reactivity of POWV mAbs against other flaviviruses. (A) Flow cytometric analysis of HEK-293T cells transfected with the C-prM-E structural genes of POWV, TBEV, LGTV, or GGYV; representative histograms from one of three experiments is shown. Untransfected cells (blue); transfected cells (red). (B) Neutralization by mAbs was assessed using an RVP-based assay (TBEV and GGYV) or FRNT (LGTV) on Vero cells. Representative dose-response curves from two to three experiments. Error bars represent the range from two technical replicates. (C) ADE of the indicated MBFV by POWV mAbs was assessed by an RVP-based assay using K562 cells. Dose-response curves from two to three experiments. (D and E) Standard (D) and mature (E) RVP preparations were assessed for sensitivity to mAb neutralization on Raji-DCSIGNR cells. Dose-response curves are shown from three to four independent repeats. Error bars represent the range from two technical replicates. Ab, antibody.