TABLE 1.
Effect of V1 modification on viral neutralization susceptibility to MAbs
| Virus | 50% Neutralization titer (IC50)a |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| b12 (anti-CD4) | IgG-CD4 (anti-CD4) | b6 (anti-CD4) | P3C8 (anti-V1) | P3E1 (anti-V3) | 447-52D (anti-V3) | 2G12 (antimannose) | 2F5 (anti-gp41) | 4E10 (anti-gp41) | |
| SF162 | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.14 ± 0.03 | 0.16 ± 0.00 | 0.001 ± 0.00 | 0.06 ± 0.00 | 0.22 ± 0.00 | 0.21 ± 0.03 | 0.34 ± 0.03 |
| SF162/YU2 V1 | 0.01 ± 0.01 | 0.02 ± 0.01 | 0.17 ± 0.02 | — | 0.002 ± 0.00 | 0.28 ± 0.07 | 0.38 ± 0.01 | 0.24 ± 0.07 | 0.70 ± 0.08 |
| SF162/JRFL V1 | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.14 ± 0.02 | — | 0.01 ± 0.01 | 0.15 ± 0.01 | 0.49 ± 0.19 | 0.23 ± 0.02 | 0.60 ± 0.03 |
| SF162/89.6 V1 | 0.05 ± 0.04 | 0.06 ± 0.01 | 1.55 ± 0.29 | — | 0.08 ± 0.01 | 2.41 ± 0.21 | 0.50 ± 0.19 | 0.41 ± 0.08 | 1.28 ± 0.27 |
| SF162/HxB2 V1 | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.10 ± 0.03 | — | 0.0003 ± 0.00 | 0.06 ± 0.01 | 0.68 ± 0.02 | 0.22 ± 0.11 | 0.48 ± 0.02 |
| ΔV1SF162 | 0.01 ± 0.00 | 0.04 ± 0.01 | 1.79 ± 0.24 | — | 0.02 ± 0.00 | 0.56 ± 0.06 | 0.17 ± 0.02 | 0.14 ± 0.02 | 0.47 ± 0.07 |
a
The values represent the MAb concentration required to achieve 50% inhibition of viral infection. Results are averages and standard deviations from two independent experiments performed in duplicate. MAbs were tested at an initial dilution of 20 μg/ml. The Env region targeted is denoted in parentheses. —, MAb did not neutralize the isolate above 50% at the highest MAb concentration tested (20 μg/ml).