KEL RBC clearance and modulation of the KEL antigen in the setting of KELIg immunoprophylaxis are similar with or without poly(I:C). (A) KEL RBCs labeled with the lipophilic dye DiO were mixed with wild-type RBCs labeled with the lipophilic dye DiI and transfused into recipients treated with KELIg, in the presence or absence of KELIg; posttransfusion RBC recovery and survival were measured and are presented as a ratio of KEL RBCs to wild-type RBCs. (B) Recovered DiO-labeled KEL RBCs were evaluated for KEL glycoprotein antigen expression after incubation with KELIg and a fluorescently conjugated anti-mouse IgG. (C) Recovered DiO-labeled KEL RBCs in animals treated with or without KELIg were also evaluated for KEL glycoprotein expression using a recombinant antibody against CD238. The data in panels A and B are representative of 3 independent experiments with 3 mice per group per experiment (total of 9 and 9 mice); the data in panel C are representative of 2 independent experiments with 2 to 3 mice per group per experiment (total of 5 and 5 mice); error bars indicate standard deviation between mice.