Blocking of mab A5-enhanced cell binding and infectivity by the FL-specific mab 4G2.
(A-D) Binding of TBEV to cells after incubation with different mabs (A5, A5+4G2, 4G2) for 1 hour at 4°C. (A) HeLa cells, (B) Vero cells, (C) HFFs, (D) immature moDCs. The y-axis indicates percent bound virus relative to input virus using RNA copy numbers determined by qPCR. (E) Infectivity of TBEV after incubation with different mabs (A5, A5+4G2, 4G2) on HeLa cells using focus formation assays. (F) TBEV production in Vero cells after infection in the presence of different mabs (A5, A5+4G2, 4G2). In contrast to HeLa cells, TBEV did not produce foci in Vero cells. Virus production was therefore measured by quantifying RNA copy numbers with qPCR. Data represent the mean +/- SEM of at least three independent experiments. The amounts of bound TBEV-mab complexes or their infectivity were compared to the corresponding values obtained with the control (ctrl, TBEV without mabs) with ANOVA followed by Dunnett’s multiple comparisons test. *, p < 0.05.