Anti-HEL antibodies reverse the ability of anti-Duffy to augment HOD RBC alloimmunization. (A) The experimental design of CD4+ OT-II cell evaluation after exposure of B6 mice to HOD RBCs in the presence or absence of anti-HEL, anti-Duffy or anti-HEL + anti-Duffy antibodies, including representative flow cytometric examination of OT-II proliferation after exposure to 109 HOD RBCs in the presence or absence of anti-HEL, anti-Duffy or anti-HEL + anti-Duffy antibodies, as indicated. (B) Quantitative analysis of OT-II proliferation, CD44, and CD69 levels after exposure of B6 mice to high-dose (109) HOD RBCs in the presence or absence of anti-HEL, anti-Duffy or anti-HEL + anti-Duffy antibodies, as indicated. (C) Schematic of HOD RBC–induced antibody formation in the presence or absence of anti-HEL, anti-Duffy, or anti-HEL + anti-Duffy antibodies. (D-E) Evaluation of the development of the anti-HEL IgM (D) and IgG (E) antibody response in the presence or absence of anti-HEL, anti-Duffy, or anti-HEL + anti-Duffy antibodies after exposure of B6 mice to 109 HOD RBCs at the indicated time points. n = 3 to 10 mice per group. Modal = all histograms scaled as a percentage of the maximum count. All plots show mean values ± standard deviation. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; and ∗∗∗∗P < .0001. These results are representative of 2 independent experiments.
