Table 2. Serum antibodies from EN1 are effective against neutralization-resistant viruses.
| No. | Virus/mutant | Clade | Serum neutralization titer (ID50) | bN-mAb neutralization (IC50) | ||
|---|---|---|---|---|---|---|
| EN1 | PG9 | PG16 | VRC01 | |||
| 1 | Du422.1 | C | 54 | 0.60 | 0.10 | >50 |
| 2 | CAP210.2.00.E8 | C | 151 | 0.30 | <0.02 | >50 |
| 3 | TV1.21 | C | 222 | <0.02 | <0.02 | >50 |
| 4 | T278.50 | CRF02_AG | 553 | 0.50 | 0.30 | >50 |
| 5 | CAP45.2.00.G3 | C | 231 | <0.02 | <0.02 | 28.30 |
| 6 | CAP45.2.00.G3/N160A | 104 | >50 | >50 | 28.20 | |
| 7 | TRO.11 | B | 1571 | >50 | 10.00 | 0.30 |
| 8 | TRO.11/N322A | 421 | >50 | 5.27 | 0.75 | |
| 9 | AC10.0.29 | B | 240 | 0.10 | <0.02 | 1.30 |
| 10 | AC10.0.29/N332A | 284 | 0.20 | <0.02 | 1.90 | |
| 11 | 172284_017 | B | 1012 | >10 | >10 | >10 |
| 12 | 172284_036 | 289 | >10 | >10 | >10 | |
| 13 | 108051_005 | B | <100 | >10 | >10 | >10 |
| 14 | 108051_005_D180N | 441 | >10 | >10 | >10 | |
| 15 | 172950_007 | B | 671 | 4.25 | 2.51 | >10 |
| 16 | 172950_007N197H | 4556 | >10 | >10 | >10 | |
| 17 | MN-3 | B | 1850 | >20 | >20 | >0.02 |
| 18 | JRCSF | B | 1597 | 0.01 | 0.01 | 0.36 |
| 19 | aMLV-SVA | Control | <20 | >50 | >50 | >50 |
Viruses/mutants represent pseudoviruses prepared using cloned envelope glycoprotein genes. Pairs of viruses from CAP45, TRO.11, AC10, 108051 and 172950_007 differ by single amino acid mutations that confer sensitivity and resistance to various bN-mAbs. Viruses 172284_017 and 172284_036 were neutralization resistant clinical isolates. For serum, virus neutralization represents the reciprocal of the serum dilution that results in 50% inhibition (ID50) of target cell infection. For mAbs, virus neutralization represents the concentration of bN-mAbs (μg/mL) that results in 50% inhibition (IC50) of target cell infection. Values in bold represent significant results where neutralization titers that are at least three times greater than those observed against the negative control (aMLV). MN-3 and JRCSF were included as neutralization sensitive positive controls.