TABLE 2.
Human CD4+ T-cell clones recognize P. falciparum CS repeat and universal T∗ epitopes contained in ICC-1132a
| Antigen | Assay results for:
|
|||||
|---|---|---|---|---|---|---|
| T-cell clone 9-2D4
|
T-cell clone 9-2E10
|
|||||
| Proliferation (SI) | IL-2 (SI) | IFN-γ (pg/ml) | Proliferation (SI) | IL-2 (SI) | IFN-γ (pg/ml) | |
| T∗ peptide | 1 | 1 | <5 | 124 | 402 | 2,374 |
| Repeat peptide | 21 | 195 | 106 | 1 | 1 | <5 |
| ICC-1132 | 10 | 44 | 22 | 128 | 364 | 2,073 |
| HBc149 | 1 | 1 | <5 | 2 | 3 | <5 |
| P. falciparum rCS | 12 | 107 | ND | 83 | 202 | 1045 |
| Control protein | 1 | 1 | <5 | 1 | 2 | <5 |
| P. falciparum sporozoites | 6 | 116 | 122 | ND | ND | ND |
| P. berghei sporozoites | 1 | 1 | <5 | ND | ND | ND |
a
T-cell clones were derived from a volunteer immunized with a malaria polyoxime vaccine (32; Calvo-Calle, unpublished). The T cells were stimulated with 10 to 20 μg of CS peptides, core particles, or recombinant CS protein (rCS) per ml or freeze-thawed extracts of 105 sporozoites, using irradiated PBL as APC. Proliferation and IL-2 assay results are expressed as SI. ND, not determined.