Cytotoxic activity of T cells specific for WT-1–derived immunogenic epitopes identified by IFNγ production assay after sensitization with the pool of overlapping pentadecapeptides spanning the sequence of the WT-1 protein when tested against WT-1+ primary leukemic cells and PHA blasts of the same origin (P < .001)
| 15-mer no. containing the dominant epitope . | Sequence identified . | Presenting HLA allele . | Cytotoxic CTL response, % (at a 50:1 effector: stimulator ratio) vs: . | |
|---|---|---|---|---|
| WT-1+ leukemia cells* . | PHA blasts† . | |||
| 1 | (−125)-(−117)RQRPHPGAL | B0702 | 67 | 2 |
| 2 | (−119)-(−111)GALRNPTAC | B0702 | 60 | 1 |
| 4 | (−110)-(−102)PLPHFPPSL | A0201 | 22 | 1 |
| 7 | (−99)-(−91)THSPTHPPR | B4001 | 65 | 5 |
| A0201 | 38 | 3 | ||
| 24-25 | (−27)-(−19)KLGAAEASA | A0201 | 37 | 8 |
| 29-30 | (−8)-(1)ASGSEPQQM | B3501 | 39 | 9 |
| 37 | 22-31GGCALPVSGA | A0201 | 47 | 6 |
| 43 | 46-54SAYGSLGGP | B4001 | 68 | 3 |
| 62-63 | 126-134RMFPNAPYL‡ | A0201 | 25 | 3 |
| 86 | 218-226RTPYSSDNL | B3503 | 48 | 1 |
| C0401 | 48 | 1 | ||
| 141 | 436-445NMHQRNHTKL | B4001 | 72 | 1 |
| 15-mer no. containing the dominant epitope . | Sequence identified . | Presenting HLA allele . | Cytotoxic CTL response, % (at a 50:1 effector: stimulator ratio) vs: . | |
|---|---|---|---|---|
| WT-1+ leukemia cells* . | PHA blasts† . | |||
| 1 | (−125)-(−117)RQRPHPGAL | B0702 | 67 | 2 |
| 2 | (−119)-(−111)GALRNPTAC | B0702 | 60 | 1 |
| 4 | (−110)-(−102)PLPHFPPSL | A0201 | 22 | 1 |
| 7 | (−99)-(−91)THSPTHPPR | B4001 | 65 | 5 |
| A0201 | 38 | 3 | ||
| 24-25 | (−27)-(−19)KLGAAEASA | A0201 | 37 | 8 |
| 29-30 | (−8)-(1)ASGSEPQQM | B3501 | 39 | 9 |
| 37 | 22-31GGCALPVSGA | A0201 | 47 | 6 |
| 43 | 46-54SAYGSLGGP | B4001 | 68 | 3 |
| 62-63 | 126-134RMFPNAPYL‡ | A0201 | 25 | 3 |
| 86 | 218-226RTPYSSDNL | B3503 | 48 | 1 |
| C0401 | 48 | 1 | ||
| 141 | 436-445NMHQRNHTKL | B4001 | 72 | 1 |
Differences in responses to WT-1+ leukemia cells and PHA blasts, analysed by paired ttest, are significant (P < .001).
Leukemia targets were derived from either immortalized leukemia cell lines or primary leukemia cells obtained from patients with WT-1+ leukemia.
PHA blasts were generated from PBMCs derived from the same patients as the WT-1+ primary leukemia cells.
Epitopes previously predicted by the computer algorithm or described in the literature.