Table 1.
Tumor-associated Antigen GD2 Specifically Potentiates IL-2 Production by 3G6-CD28–transduced Jurkat T Cells Activated with Immobilized OKT3
| IL-2 production (pg/ml) | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| — — | 9.3 — | A1G4 — | EL4GD2− 5:1 — | EL4GD2− 1:1 — | EL4 5:1 — | EL4 1:1 — | EL4 5:1 F(ab′)2 * | EL4 1:1 F(ab′)2 * | ||||||||||
| 3G6-CD28 | 47 ± 15 | 577 ± 79 | 189 ± 57 | 39 ± 6 | 49 ± 4 | 317 ± 33 | 138 ± 22 | 15 ± 5 | 19 ± 2 | |||||||||
| 3G6-CD28TR | 11 ± 9 | 490 ± 22 | 4 ± 5 | 2 ± 1 | 7 ± 5 | 2 ± 4 | 4 ± 2 | 4 ± 2 | 4 ± 2 | |||||||||
| NTP | 5 ± 5 | 499 ± 32 | 11 ± 2 | <1 | 7 ± 5 | <1 | <1 | <1 | 8 ± 3 | |||||||||
Results are the means ± SD obtained from duplicates. The NTP marker was used as an irrelevant control that could be monitored for cell-suface expression in parallel to 3G6-CD28 and 3G6-CD28TR. T cells (2.5 × 105/ml) were incubated with OKT3 (10 μg/ml, immobilized on sheep anti– mouse beads [3 beads/cell]) and stimulated with soluble 9.3 (ascites 1:1,000), A1G4 (2 μg/ml), EL4, or the GD2 − variant EL4GD2−.
*
In anti-GD2 blocking conditions, EL4 cells were preincubated with anti-GD2 F(ab′)2 fragment 3F8 (10 μg/ml). After 24 h, supernatants were collected, and IL-2 was measured by ELISA.