Table II.
Anti–GBV-C E2 Abs neutralize diverse HIV isolates
| Ab Description | Ab Identification | HIV Isolate Number (see Table I for characteristics)
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ||
| Human anti-E2 polyclonal IgG | I-P1 | 8.1a | 3.4 | 2.9 | 1.6 | 2.2 | 2.3 | 4.1 | 3.5 | 2.8 | 3.7 | 5.1 |
| I-P2 | 2.6 | 8.3 | ||||||||||
| I-P3 | 5.8 | 1.7 | <10 | <10 | ||||||||
| Rabbit anti-E2 protein polyclonal IgG | R1b,c | 4.3 | 5.0 | |||||||||
| R2 | 1.5 | 2.1 | 1.1 | 3.1 | 1.6 | <10 | <10 | <10 | <10 | 1.5 | 1.2 | |
| R3 | 9.3 | 10 | ||||||||||
| R4 | 5.6 | 4.9 | <10 | <10 | <10 | <10 | <10 | 2.1 | 1.7 | |||
| Rabbit anti-E2 peptide polyclonal IgG | rPep-1c | >50 | >50 | >50 | >50 | >50 | >50 | >50 | ||||
| rPep-2 | >50 | >50 | >50 | >50 | ||||||||
| Mouse anti-E2 monoclonal IgG | M1 (VS) | 1.4 | 2.5 | <5 | <5 | <5 | <5 | <5 | <5 | <5 | ||
| M5 | <5 | <5 | ||||||||||
| M6 | 1.8 | 1.1 | ||||||||||
| Human anti-HIV monoclonal IgG | 2F5 | 1.7 | ||||||||||
| 4E10 | 1.3 | |||||||||||
| 2G12 | >5 | 0.2 | ||||||||||
IC50 results >5 μg/ml for mAbs or >30 μg/ml for polyclonal Abs are in bold.
a
Neutralization assays were performed in PBMCs for R5 isolates and MT-2 cells for X4 isolates.
b
Concentration (micrograms per milliliter) required to reduce HIV infectivity by 50% compared with control Ab (IC50).
c
Rabbits were immunized with either rGBV-C E2 protein (anti-E2) or the 17-aa peptide Ag recognized by the M6 murine mAb (anti-rPep) as described in Materials and Methods. Blank, not tested. The highest or lowest concentration tested is equal to or more than or less than, respectively.