Hematopoietic chimerism in BALB/c mice given varying sublethal doses of radiation and C57BL/6 bone marrow in the presence or absence of anti-CD154 monoclonal antibody
| Radiation (rad) . | Anti-CD154 mAb . | Number of Chimeric Mice (%) . | Percentage of Donor-Origin PBMCs in Chimeric Mice . | |
|---|---|---|---|---|
| Number of Injections . | Dose . | |||
| 300 | 0 | — | 0/10 (0%) | — |
| 4 | 0.25 mg | 0/5 (0%) | — | |
| 14 | 0.25 mg | 0/5 (0%) | — | |
| 2 | 0.5 mg | 0/5 (0%) | — | |
| 400 | 0 | — | 0/10 (0%) | — |
| 4 | 0.25 mg | 2/4 (50%) | Both >99% | |
| 14 | 0.25 mg | 4/9 (44%) | All >99% | |
| 2 | 0.5 mg | 9/9 (100%) | All >99% | |
| 500 | 0 | — | 10/10 (100%) | All >99% |
| 4 | 0.25 mg | 4/4 (100%) | All >99% | |
| 14 | 0.25 mg | 8/9 (89%) | All >99% | |
| 2 | 0.5 mg | 9/9 (100%) | All >99% | |
| Radiation (rad) . | Anti-CD154 mAb . | Number of Chimeric Mice (%) . | Percentage of Donor-Origin PBMCs in Chimeric Mice . | |
|---|---|---|---|---|
| Number of Injections . | Dose . | |||
| 300 | 0 | — | 0/10 (0%) | — |
| 4 | 0.25 mg | 0/5 (0%) | — | |
| 14 | 0.25 mg | 0/5 (0%) | — | |
| 2 | 0.5 mg | 0/5 (0%) | — | |
| 400 | 0 | — | 0/10 (0%) | — |
| 4 | 0.25 mg | 2/4 (50%) | Both >99% | |
| 14 | 0.25 mg | 4/9 (44%) | All >99% | |
| 2 | 0.5 mg | 9/9 (100%) | All >99% | |
| 500 | 0 | — | 10/10 (100%) | All >99% |
| 4 | 0.25 mg | 4/4 (100%) | All >99% | |
| 14 | 0.25 mg | 8/9 (89%) | All >99% | |
| 2 | 0.5 mg | 9/9 (100%) | All >99% | |
BALB/c (H2d) mice were irradiated, transfused intravenously with 25 × 106 C57BL/6 (H2b) bone marrow cells, and injected intraperitoneally with anti-CD154 mAb as indicated. The schedule of anti-CD154 mAb (relative to irradiation and bone marrow transplantation on day 0) was as follows. Recipients given 2 injections were treated on days 0 and +3; recipients of 4 injections on days −3, 0, +3, +7; and recipients of 14 injections on days −3, 0, and twice weekly thereafter. The percentage of H2b donor-origin PBMCs was determined by flow cytometry 4 to 6 weeks after irradiation and bone marrow transplantation. The presence of chimerism was defined as at least 1% donor-origin cells.