Evaluation of the role of activating Fcγ receptors and complement component C3 in IgG-mediated clearance of incompatible hGPA-Tg-mRBCs
| Mice . | Passive immunization . | No. of mice . | Percent 4-h RBC survival, mean ± 1 SD . |
|---|---|---|---|
| Wild type | None | 6 | 98.2 ± 1.6 |
| Wild type | NaM10-2H12 | 6 | 26.8 ± 8.1 |
| Fcgr KO | NaM10-2H12 | 2 | 56.5 ± 0.4 |
| C3 KO | NaM10-2H12 | 6 | 81.7 ± 7.2 |
| Fcgr/C3 double-KO | NaM10-2H12 | 6 | 80.6 ± 9.1 |
| Wild type | None | 6 | 98.2 ± 1.6 |
| Wild type | 10F7 | 6 | 27.2 ± 14.5 |
| Fcgr KO | 10F7 | 6 | 85.7 ± 19.9 |
| C3 KO | 10F7 | 6 | 58.6 ± 4.5 |
| Fcgr/C3 double-KO | 10F7 | 4 | 80.2 ± 9.2 |
| Mice . | Passive immunization . | No. of mice . | Percent 4-h RBC survival, mean ± 1 SD . |
|---|---|---|---|
| Wild type | None | 6 | 98.2 ± 1.6 |
| Wild type | NaM10-2H12 | 6 | 26.8 ± 8.1 |
| Fcgr KO | NaM10-2H12 | 2 | 56.5 ± 0.4 |
| C3 KO | NaM10-2H12 | 6 | 81.7 ± 7.2 |
| Fcgr/C3 double-KO | NaM10-2H12 | 6 | 80.6 ± 9.1 |
| Wild type | None | 6 | 98.2 ± 1.6 |
| Wild type | 10F7 | 6 | 27.2 ± 14.5 |
| Fcgr KO | 10F7 | 6 | 85.7 ± 19.9 |
| C3 KO | 10F7 | 6 | 58.6 ± 4.5 |
| Fcgr/C3 double-KO | 10F7 | 4 | 80.2 ± 9.2 |
All mice were on the C57BL/6 background. Mice were passively immunized intraperitoneally with either 50 μg of the IgG3 NaM10-2H12 anti-hGPA mAb or 500 μg of the IgG1 10F7 anti-hGPA mAb 16 hours prior to transfusion. All mice were then transfused with 51Cr-labeled hGPA-Tg-mRBCs. In mice immunized with 10F7, clearance of incompatible mRBCs was highly dependent on the presence of activating Fcγ receptors and moderately dependent on C3. In contrast, clearance of incompatible RBCs in mice immunized with NaM10-2H12 was moderately dependent on activating Fcγ receptors and highly dependent on C3.