TABLE 2.
Epitope specificity of serum neutralizing antibodies
| Group | Animal | 50% Neutralization titer (IC50)a
|
% Reduction in neutralization at the IC70
|
Percent increase in neutralization at the IC50 with sCD4d | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 wpb | 4 wpb | V1 | V1V2-CP | V3 | V3-CP | V3 scr.b | 2F5c | 4E10c | |||
| SF162 | A02177 | 4,050 ± 354 | 1,917 ± 567 | 24% ± 6% | 41% ± 11% | 7% ± 6% | — | — | — | — | |
| A02179 | 4,050 ± 354 | 733 ± 231 | 61% ± 24% | 52% ± 4% | 9% ± 8% | — | — | — | — | ||
| A02186 | 1,180 ± 113 | 260 ± 14 | —e | 33% ± 23% | 16% ± 7% | 14% | — | — | — | ||
| A02188 | 4,200 ± 1,414 | 3,500 ± 707 | 55% ± 1% | 54% ± 6% | 9% ± 2% | — | — | — | — | ||
| 02193 | 390 ± 113 | 275 ± 35 | 41% ± 5% | 36% ± 18% | 8% ± 2% | 9% | — | — | — | ||
| Median | 4,050 | 733 | 41% | 41% | 9% | — | — | — | — | 30% ± 5% | |
| ΔV2 | 02187 | 687 ± 103 | 237 ± 97 | 63% ± 4% | 46% ± 5% | 20% ± 1% | — | — | — | — | |
| A02183 | 823 ± 282 | 695 ± 148 | 55% ± 2% | 48% ± 8% | 7% ± 5% | — | — | — | — | ||
| 02184 | 640 ± 53 | 190 ± 14 | 53% ± 0% | 44% ± 3% | 5% ± 2% | — | — | — | — | ||
| A02178 | 1,047 ± 81 | 505 ± 219 | 26% ± 8% | 32% ± 15% | — | — | — | — | — | ||
| Median | 755 | 371 | 54% | 45% | 6% | — | — | — | — | 28% ± 15% | |
| ΔV3 | AV28 | 850 ± 212 | 225 ± 92 | 67% ± 4% | 70% ± 4% | — | — | — | — | — | |
| BD59 | 413 ± 4 | 193 ± 116 | 72% ± 11% | 70% ± 4% | — | — | — | — | — | ||
| CD15 | 280 ± 113 | 140 ± 98 | 79% ± 0% | 71% ± 1% | — | — | — | — | — | ||
| Median | 413 | 193 | 72% | 70% | — | — | — | — | — | 27% ± 7% | |
| ΔV2ΔV3 | CN63 | 142 ± 40 | 106 ± 48 | 88% ± 2% | 62% ± 17% | — | — | — | — | — | |
| M733 | 120 ± 21 | 93 ± 13 | 64% ± 0% | 55% ± 7% | — | — | — | — | — | ||
| N422 | 1,335 ± 474 | 633 ± 350 | 49% ± 6% | 50% ± 0% | — | — | — | — | — | ||
| Median | 142 | 106 | 64% | 55% | — | — | — | — | — | 33% ± 7% | |
| Mock | AM10 | — | — | NDf | ND | ND | ND | ND | ND | ND | ND |
| AM94 | — | — | ND | ND | ND | ND | ND | ND | ND | ND | |
| AP18 | — | — | ND | ND | ND | ND | ND | ND | ND | ND | |
| Median | — | — | ND | ND | ND | ND | ND | ND | ND | ND | |
| SHIVSF162P4 | C640, day 178 | 17,500 ± 3,535 | — | — | 36% | — | — | — | ND | ND | |
| C640, day 304 | 40,000 ± 20,000 | — | 36% | 10% | — | — | — | ND | ND | ||
| C640, day 643 | 5,000 ± 50 | — | — | 18% | 19% | — | — | — | 25% ± 0% | ||
| HIVIGg | 13.5 ± 8 | — | — | 33% | 29% | — | — | — | 29% ± 1% | ||
a
Sera were collected 2 and 4 weeks following the gp140 immunization (wpb). Serum from animal C640 was collected at the indicated days post-SHIVSF162P4 infection.
b
V3 scr., V3 scrambled peptide.
c
Peptides recognized by MAbs 2F5 and 4E10.
d
This indicates detection of NAbs following incubation of pseudovirus with soluble CD4.
e
—, <5% reduction in the presence of peptide/chimeric protein.
f
ND denotes not done.
g
Titers recorded for HIVIG are in μg/ml.