TABLE 1.
IC50 values (μm) for CCR5 ECL2 peptides in neutralization assays
| Peptide | R5a |
R5/X4a (89.6)b | X4a |
||
|---|---|---|---|---|---|
| YU2b | BaL26b | HxB2b | NL4-3b | ||
| 1 | 136 ± 49 | 138 ± 36 | 203 ± 54 | 89 ± 31 | 103 ± 37 |
| 2N | NAc | NA | NA | NA | NA |
| 2C | 28 ± 7 | 65 ± 3 | NA | 54 ± 2 | 53 ± 2 |
| 3 | 237 ± 31 | 612 ± 21 | NA | 374 ± 28 | 600 ± 24 |
| 4 | NA | NA | NA | NA | NA |
a Virus tropism. R5 and X4 refer to CCR5- and CXCR4-using HIV-1 strains, respectively, and R5/X4 refers to dual tropic strains. Neutralization assays were performed as described previously (37).
b HIV strain.
c Not active, NA.