The elimination of Crry/DAF/C3^−/−erythrocytes by the alternative pathway of complement via complement receptor (CR)–mediated erythrophagocytosis.

(A) Crry/DAF/C3^−/− erythrocytes were cleared normally in Ig^−/− (red circles; n = 4), C4^−/− (green circles; n = 4), and FcRγ^−/− mice (black triangles; n = 3). (B) Crry/DAF/C3^−/− erythrocytes had similar clearance kinetics in C5-deficient mice (green triangles; n = 4) as in wild-type mice (red circles; n = 3). (C-F) Sequestration of CFSE-labeled Crry/DAF/C3^−/− erythrocytes in the spleen of wild-type recipients (panel C, × 100 ; panel E, × 200), but not that of C3^−/− mice (panel D, × 100; panel F, × 200), at 24 hours after transfusion.