TABLE 7.
ELISPOT assay for IFN-γ production by PCI-13-reactive HLA-A2-restricted CTLa
| Assay conditions | Frequency (%) of IFN-γ-producing cells |
|---|---|
| CTL.1 (spontaneous release) | 1/1,000 (0.1) |
| CTL.1 + Ir PCI-13 | 1/8 (12.5) |
| CTL.2 (spontaneous release)b | 1/1,000 (0.1) |
| CTL.2 + Ir PCI-13 | 1/32 (3.1) |
| CTL.2 + Ir PCI-13 | 1/50 (2.0) |
| CTL.2 + Ir PCI-13 + W6/32 Abc | 1/1,000 (0.1) |
| CTL.2 + Ir HRd | 1/1,000 (0.1) |
a
Two different PCI-13 (SCCHN)-reactive CTL lines were tested. T cells were titrated into wells of ELISPOT plates (6 × 104 to 2 × 103 cells) in triplicate and coincubated with irradiated (Ir) PCI-13 cells (10 lymphocytes/1 tumor cell) for 48 h at 37°C. Spots were counted to determine the frequency of IFN-γ-producing T cells in each coculture.
b
The CTL.2 line was tested on different days 2 weeks apart.
c
PCI-13 cells were preincubated with anti-MHC class I Ab (w6/32) for 30 min.
d
CTL.2 cells were coincubated with the HLA-A2+ gastric carcinoma cell line used as a control.