Table 2.
Breadth of DNA-induced IFN-γ responses (fresh and frozen PBMCs)
| Peptide | Residues | HLA restriction | Sequence | Range of net SFCs per 102 PBMCs (geomean) | Number of positive assays/total assays (%) | Number of responders/number tested |
|---|---|---|---|---|---|---|
| Class I | ||||||
| HLA-A2 | ||||||
| A2.386 | 386–394 | A2 supertype | GLIMVLSFL | 11–543 (36.2) | 23/70 (32.9%) | 11/14 |
| A2.7 | 7–16 | A2 supertype | ILSVSSFLFV | 13–163 (39.3) | 12/70 (17.1%) | 10/14 |
| A2.1 | 1–10 | A2.1 | MMRKLAILSV | 12–56 (32.9) | 4/70 (5.7%) | 5/14 |
| A2.319 | 319–327 | A2.1 | YLNKIQNSL | 17.5 | 1/70 (1.4%) | 1/14 |
| Non-HLA-A2 | ||||||
| A1.310 | 310–319 | A1 | EPSDKHIKEY | 19–29.5 (23.7) | 2/14 (14.3%) | 2/7 |
| A3/11.336 | 336–345 | A3/11 supertype | VTCGNGIQVR | 0/12 (0%) | 0/4* | |
| B7.285 | 285–294 | B7 | MPNDPNRNV | 20–23 (21.4) | 2/14 (14.3%) | 1/4 |
| B8.86 | 86–94 | B8 | LRKPKHKKL | 0/12 (0%) | 0/4 | |
| B35.353 | 353–360 | B35 | KPKDELDY | 0/3 (0%) | 0/1 | |
| Class II | ||||||
| DR.1 | 1–20 | DR (A2.1 and A2 supertype) | MMRKLAILSVSSFLFVEALF | 12–177 (30.7) | 24/70 (34.3%) | 11/14 |
| DR.375 | 375–397 | DR (A2 supertype) | SSVFNVVNSSIGLIMVLSFLFLN | 12–519 (40.7) | 31/70 (44.3%) | 11/14 |
| DR.316 | 316–335 | DR (A2.1) | IKEYLNKIQNSLSTEWSPCS | 10–27 (16.2) | 6/48 (12.5%) | 5/14 |
| DR.346 | 346–365 | Th3R (B35) | IKPGSANKPKDELDYANDIE | 10–37.7 (22.2) | 4/50 (8.0%) | 3/14 |
| DR.281 | 281–305 | DR (B7) | QGHNMPNDPNRNVDENANANSAVKN | 22.3 | 1/14 (7.1%) | 1/4 |
| DR.363 | 363–383 | DR | DIEKKICKMEKCSSVFNVVNS | 10–59 (21.0) | 13/58 (22.4%) | 6/14 |
| Positive control | ||||||
| Flu. M A2.1 | 58–66 | A2.1 | GILGFVFTL | 14–837 (88.9) | 118/122 (96.7%) | 20/20 |
PfCSP peptide sequences and residue numbers were based on those of P. falciparum clone 3D7 (GenBank no. X15363). Residues known to vary among isolates are indicated in bold. Nested class I-restricted epitopes within the DR binding peptides are underlined.
*
None of the four volunteers tested expressed the HLA-A*0301 allele, but all expressed one of the A3-superfamily alleles HLA-A*1101, A*3101, and A*6801.