Table 5.
Neutralization of HIV-1 primary isolates from different clades by m46, 2F5 and 4E10 measured by a pseudovirus assay using cell lines with different CCR5 surface concentrations.
Antibodies at various concentrations were mixed with viruses pseudotyped with the Env from different clades of HIV-1 for 30 minutes at 37°C and mixed with cells expressing high or low CCR5 concentrations in triplicate wells. The mean luminescence readings were determined 3 days later and IC50 (μg/ml) was calculated at the antibody concentration at which 50% neutralization was observed. The mean of three measured IC50s for each antibody/virus/cell combination are presented (in μg/ml); the standard deviation was on average 5% and did not exceed 10%, the numbers in parentheses are the percentages neutralization measured at those concentrations used (50 or 25 μg/ml).
| HIV-1 Clade | Antibody | High CCR5 | Low CCR5 |
|---|---|---|---|
| Fab m46 | >50 (40%) | 18 | |
| 92UG037.8 (Clade A) | IgG m46 | >50 (35%) | 25 |
| IgG 2F5 | 0.3 | 0.2 | |
| IgG 4E10 | 1 | 0.2 | |
|
| |||
| Fab m46 | 45 | 5 | |
| Bal (Clade B) | IgG m46 | 30 | 8 |
| IgG 2F5 | 6 | 1 | |
| IgG 4E10 | 12 | 0.1 | |
|
| |||
| Fab m46 | >50 (44%) | 15 | |
| GXC-44 (Clade C) | IgG m46 | >50 (39 %) | 25 |
| IgG 2F5 | >25 (20 %) | >25 (30 %) | |
| IgG 4E10 | 15 | 8 | |
|
| |||
| Fab m46 | 20 | 10 | |
| Z2Z6 (Clade D) | IgG m46 | 10 | 3 |
| IgG 2F5 | 18 | 9 | |
| IgG 4E10 | 22 | 10 | |
|
| |||
| Fab m46 | 28 | 5 | |
| CM243 (Clade E) | IgG m46 | 25 | 6 |
| IgG 2F5 | 3.2 | 1 | |
| IgG 4E10 | 1.5 | 0.6 | |