Table 1.
Binding and neutralizing activity of human monoclonal antibodies
| Competitionbinding groupa | Clone | Binding to RBP head domain from indicated virus in ELISA EC50 valuesb in μg/mL (Area under the curve) |
Neutralization of indicated virus | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| IC50 valuesd in μg/mL (Area under the curve) | IC80 valuesd in μg/mL (Max % Inhibition) | |||||||||
| HeV | NiVB | NiVM | HeV | NiVB | NiVM | HeV | NiVB | NiVM | ||
| A | HENV-1 | 0.19 (3.27) | >c (0.61) | > (0.67) | 0.63 (187) | > (7.98) | > (22.6) | 1.70 (100) | > (32.7) | > (34.9) |
| B | HENV-32 | 0.36 (3.71) | 0.96 (6.6) | 0.42 (8.0) | 0.27 (198) | 0.38 (194) | 0.31 (201) | 1.26 (100) | 1.14 (100) | 2.15 (100) |
| HENV-21 | 0.42 (3.30) | 2.44 (5.5) | 0.87 (7.2) | 1.94 (133) | 1.91 (140) | 2.01 (129) | 5.54 (100) | 4.09 (100) | 8.44 (92.4) | |
| HENV-10 | 0.21 (5.49) | > (0.63) | > (0.76) | 0.62 (181) | 1.07 (140) | 0.22 (152) | 1.71 (100) | 9.42 (96.3) | 1.44 (84.2) | |
| B/C | HENV-2 | 0.13 (5.81) | 0.51 (6.4) | 0.28 (9.0) | 0.78 (166) | 1.39 (143) | 0.75 (186) | 2.57 (100) | 4.88 (95.8) | 2.67 (100) |
| C | HENV-9 | 0.60 (3.19) | > (0.57) | 0.75 (4.2) | 0.37 (195) | > (11.9) | 8.93 (69.2) | 1.88 (100) | > (35.2) | > (61.5) |
| HENV-43 | 0.86 (6.87) | > (0.59) | 1.49 (1.4) | 0.61 (178) | > (9.2) | > (45.2) | 2.39 (100) | > (40.0) | > (51.9) | |
| D | HENV-18 e | 0.21 (5.80) | > (0.56) | > (0.60) | 0.38 (211) | > (5.7) | > (51.1) | 1.16 (100) | > (31.4) | > (50.8) |
| HENV-19 e | 0.25 (3.69) | > (0.52) | > (0.61) | 0.35 (209) | > (7.2) | 8.08 (43.1) | 0.89 (100) | > (33.9) | > (49.2) | |
| E | HENV-26 | 0.14 (5.39) | 0.09 (10.5) | 0.07 (11.0) | 0.07 (281) | 0.03 (289) | 0.040 (293) | 0.19 (100) | 0.12 (100) | 0.11 (100) |
Experiments were conducted with 2 or 3 biological replicates, each with 2 technical replicates, with consistent results. Binding data from one representative experiment are shown, with neutralization data combined from 3 independent experiments.
Competition-binding group, as determined by data in Figure 1.
50% maximal effective concentration.
The “>” symbol indicates half maximal binding or neutralization is not achieved below the highest concentration tested: 20 μg/mL for HeV RBP binding, 50 μg/mL for NiVM or NiVB binding, or 50 μg/mL for neutralization of each of the three viruses.
50% maximal inhibitory concentration.
After all functional studies were completed, antibody variable gene sequencing later revealed the independently-derived clones HENV-18 and -19 shared identical antibody variable gene sequences (Table S1).