AMIS: the degree to which each antibody inhibited the HEL-specific IgM response 7 days after HOD-RBC transfusion and expressed as percent inhibition of alloimmunization (–, <20%; +, 20%-49%; ++, 50%-69%; +++, 70%-89%; and ++++, >90%).

RBC clearance: the degree to which HOD-specific antibodies induced HOD-RBC clearance from the circulation in the recipient mouse. This was calculated based on the percentage of transfused PKH26⁺HOD-RBCs remaining in circulation in the recipient mouse in comparison with before antibody injection (–, <25%; +, 25%-35%; ++, 36%-49%; +++, 50%-69%; and ++++, >70%).

Antigen loss: the degree to which the antibody induced loss of the epitope from HOD-RBCs recovered from recipient mice 24 hours after antibody injection. This was calculated based on the percentage of antigen remaining on recovered HOD-RBCs (–, <5%; +, 5%-24%; ++, 25%-49%; +++, 50%-69%; and ++++, >70%).

RBC membrane loss: the degree to which the antibody induced loss of PKH26 membrane fluorescence from HOD-RBCs recovered 24 hours after antibody injection. Expressed as the percentage of membrane fluorescence lost (–, <2.4%; +, 2.5%-24%; ++, 25%-49%; +++, 50%-69%; and ++++, >70%).

N/T: not tested.

∗Symbols for each experimental group are explained in Figure 2.

†The results are shown in supplemental Figure 4.

‡The results are shown in supplemental Figure 5.