Effect of CD28 Costimulation on Activation-Induced Cell Death of CD3x19-Targeted T Cells in Vivo*
| . | Antibodies and Cells Injected . | |||
|---|---|---|---|---|
| T cells | + | + | + | + |
| Nalm-6 target cells | − | + | + | + |
| Anti-CD19 + anti-CD3 | − | + | − | − |
| CD3x19 bs ab | − | − | + | + |
| Anti-CD28 | − | − | − | + |
| . | Antibodies and Cells Injected . | |||
|---|---|---|---|---|
| T cells | + | + | + | + |
| Nalm-6 target cells | − | + | + | + |
| Anti-CD19 + anti-CD3 | − | + | − | − |
| CD3x19 bs ab | − | − | + | + |
| Anti-CD28 | − | − | − | + |
| . | Percentage of Apoptotic Cells . | |||
|---|---|---|---|---|
| Animal 1 | 6.1 | 5.1 | 21.0 | 11.1 |
| Animal 2 | 9.0 | 8.9 | 30.0 | 14.8 |
| Animal 3 | 12.5 | 11.3 | 36.0 | 17.4 |
| Mean | 9.2 | 8.4 | 30.7 | 14.4 |
| SD | 3.2 | 3.1 | 6.1 | 3.2 |
| . | Percentage of Apoptotic Cells . | |||
|---|---|---|---|---|
| Animal 1 | 6.1 | 5.1 | 21.0 | 11.1 |
| Animal 2 | 9.0 | 8.9 | 30.0 | 14.8 |
| Animal 3 | 12.5 | 11.3 | 36.0 | 17.4 |
| Mean | 9.2 | 8.4 | 30.7 | 14.4 |
| SD | 3.2 | 3.1 | 6.1 | 3.2 |
Groups of 3 SCID mice were injected intraperitoneally with Nalm-6 (107) and activated T cells (5 × 107). Control groups were mock-injected with PBS, or monospecific control antibodies (anti-CD19 (HD37) and anti-CD3 (OKT3), 100 μg each). The other groups were treated with CD3x19 bs ab (200 μg), or CD3x19 plus anti-CD28 (50 μg/mL). After 16 hours, the cells were washed out of the peritoneal cavity, B cells were depleted as described above, and cells were stained for DNA strand breaks using ISNT. Percentages of strand-break–positive cells as a marker for apoptosis were measured on the single level using a FACSort flow cytometer.