Table 2.
Comparison of the GrB ELISPOT, IFN-γ ELISPOT and 51Cr-release assays for measuring Lymphokine Activated Killer (LAK) cell activity.
| Effector:Target Ratio | 51Cr-Release Assaya (% Cytotoxicity ± SE) | IFN-γ ELISPOT Assayb (Spots/well ± SE) | GrB ELISPOT Assayc (Spots/well ± SE) |
| 20:1 | 42 ± 10 | TNTCd | TNTC |
| 10:1 | 30 ± 10 | TNTC | TNTC |
| 5:1 | 22 ± 6 | TNTC | TNTC |
| 2.5:1 | 10 ± 3 | TNTC | TNTC |
| 1:1 | 5 ± 1 | TNTC | TNTC |
| 0.4:1 | 4 ± 1 | 227 ± 16 | 282 ± 18 |
| 0.2:1 | 2 ± 1 | 182 ± 8 | 193 ± 12 |
| 0.1:1 | 2 ± 2 | 121 ± 14 | 117 ± 12 |
| 0.04:1 | 1 ± 0 | 61 ± 13 | 54 ± 11 |
| 0.02:1 | 1 ± 0 | 29 ± 8 | 37± 7 |
a The 51Cr-release assay was performed with the effector:target cell ratio as specified for 4 h at 37°C. Data presented as average cytotoxicity ± SE (n = 3).
b The IFN-γ ELISPOT assay was performed with K562 cells at a constant number of 5 × 104 cells per well and effector:target cell ratio as specified for 24 h at 37°C. Data presented as average spots/well ± SE (n = 3).
cThe granzyme B ELISPOT assay was performed with K562 cells at a constant number of 5 × 104 cells per well and effector:target cell ratio as specified for 4 h at 37°C. Data presented as average spots/well ± SE (n = 3).
dTNTC= Too numerous to count accurately.