TABLE 3.
Effects of variation in an HIV-1 Env Th- cell epitope on the proliferative responses of MHC class II-restricted CD4+ Th- cell lines
| Isolate | Sequence | Peptidea | Proliferative responseb of Th-cell line:
|
|
|---|---|---|---|---|
| 233.00 | 431.78 | |||
| HXBc2 | YKYKVVKIEPLGV | Index | +++ | +++ |
| VE3 | -----I------- | V489I | +++ | ++ |
| RF | ------R------ | K490R | − | − |
| VE7 | ------Q------ | K490Q | − | − |
| MN | ------T------ | K490T | − | − |
| QZ4589 | ------E------ | K490E | − | − |
| 4995 | -------V----- | I491V | +++ | +++ |
| GUN | ----------I-- | L494I | +++ | +++ |
| SF2B13 | ------------I | V496I | +++ | +++ |
| 68A | ------------L | V496L | +++ | +++ |
HIV-1 Env variant peptides were named with the nomenclature X#Y, where X represents the index peptide amino acid residue, # represents the amino acid position within Env, and Y represents the amino acid substitution observed at position #.
Results are expressed as the concentration of peptide required to give 50% maximal proliferation of the Mamu-DR*W201-restricted rhesus monkey CD4+ Th- cell lines: +++, ≤0.5 μg/ml; ++, 0.5 to 5.0 μg/ml; +, 5.0 to 50 μg/ml; −, >50 μg/ml. In the presence of medium alone, both T-cell lines had a background of less than 100 cpm. Fifty percent maximal proliferation was defined as 2,000 cpm for cell line 233.00 and 11,900 cpm for cell line 431.78.