Levels of detectable anti-KEL IgG bound to transfused KEL2 RBCs decreases in immunized WT and FcγR KO animals to 24 hours posttransfusion. (A) Detectable IgG bound to transfused KEL2 RBCs in WT, FcγR KO, or C3 KO animals passively transferred with polyclonal anti-KEL (solid line) or saline (shaded histogram); representative plots are shown; h, hour. (B) Compilation graphs of adjusted MFI of detectable IgG bound to KEL2 RBCs in WT, FcγR KO, or C3KO animals transferred with polyclonal anti-KEL, with background signal from animals transferred with saline subtracted out. These data are representative of 5 independent experiments, with 3-5 animals/group/experiment.