Table 2.

Antibody-dependent DV2 infection of myeloid cells

CellsDV2 strain% Positive cellsa ± SEM with:PFU/mlb ± SEM with:
No MAb4G2 MAbNo MAb4G2 MAb
U93716681<0.223 ± 84.4 × 103 ± 1.6 × 103 3.6 × 106 ± 1.7 × 106
C0477<0.20.8 ± 0.301.8 × 102 ± 1.2 × 102
K0049<0.22.6 ± 0.708.9 × 103 ± 2.2 × 103
N9622<0.2<0.200
THP-116681<0.21.4 ± 0.308.1 × 103 ± 1.3 × 103
C0477<0.20.2 ± 0.100
K0049<0.2<0.203.3 × 101 ± 2.6 × 101
N9622<0.2<0.200
  • a U937 or THP-1 cells were exposed to DV2 strains (16681, MOI of 10; K0049, MOI of 4.5; N9622, MOI of 3) in the absence (no MAb) or presence (4G2) of an enhancing MAb. After incubation for 96 h, cells were processed for flow cytometry. The data are the averages of three experiments. The detection of 0.2% positive cells approaches the sensitivity of this assay.

  • b After exposure of U937 or THP-1 cells to DV2 strains, supernatants were harvested for plaque assays. The data are the averages of three experiments. A value of zero indicates no plaques were detected in any of the experiments.