Veto Activity of C57BL/6 Sca-1+Lin− Cells
| Cells per Culture . | Stimulator and Target Origin . | C57BL/6 Veto Cells . | CTL-p Activity . | |
|---|---|---|---|---|
| % Responding Cultures . | Inhibition (%) . | |||
| 40,000 | C57BL/6 | — | 56 | — |
| C57BL/6 | Sca-1+Lin− | 0 | 100 | |
| C57BL/6 | Sca-1− | 81 | None | |
| BALB/c | — | 80 | — | |
| BALB/c | Sca-1+Lin− | 100 | None | |
| BALB/c | Sca-1− | 93 | None | |
| 10,000 | C57BL/6 | — | 19 | — |
| C57BL/6 | Sca-1+Lin− | 0 | 100 | |
| C57BL/6 | Sca-1− | 44 | None | |
| BALB/c | — | 44 | — | |
| BALB/c | Sca-1+Lin− | 87 | None | |
| BALB/c | Sca-1− | 69 | None | |
| Cells per Culture . | Stimulator and Target Origin . | C57BL/6 Veto Cells . | CTL-p Activity . | |
|---|---|---|---|---|
| % Responding Cultures . | Inhibition (%) . | |||
| 40,000 | C57BL/6 | — | 56 | — |
| C57BL/6 | Sca-1+Lin− | 0 | 100 | |
| C57BL/6 | Sca-1− | 81 | None | |
| BALB/c | — | 80 | — | |
| BALB/c | Sca-1+Lin− | 100 | None | |
| BALB/c | Sca-1− | 93 | None | |
| 10,000 | C57BL/6 | — | 19 | — |
| C57BL/6 | Sca-1+Lin− | 0 | 100 | |
| C57BL/6 | Sca-1− | 44 | None | |
| BALB/c | — | 44 | — | |
| BALB/c | Sca-1+Lin− | 87 | None | |
| BALB/c | Sca-1− | 69 | None | |
Spleen cells from C3H/HeJ mice (2 × 106/mL) were incubated for 5 days with irradiated (25 Gy) allogeneic spleen cells (1 × 106/mL) from C57BL/6 (stem cell matched) or BALB/c (third-party) mice. C57BL Sca-1+Lin− or Sca-1− cells were added to the primary MLC at a 0.5:1 veto:responder cell ratio. The responder cells were then recultured under limiting dilution conditions for 7 days. Cells were then harvested from individual limiting dilution culture wells and assayed for cytotoxic activity by 51Cr-release assay as described in Materials and Methods.