Fig. 5

High-affinity binding of recombinant human ApoE ε2, ε3, and ε4 to recombinant human TREM2. In an ELISA-based binding assay with recombinant human TREM2 and recombinant human ApoE, ApoE ε2 (inverted green triangle), ApoE ε3 (light blue diamond), and ApoE ε4 (red triangle) isoforms bound to human TREM2 in vitro with K _d of 13, 16, and 9.5 nM, respectively. The points depict mean ± SEM of all responses that were measured in triplicates from three independent experiments. Data from each ApoE isoform was normalized individually as described in the “Methods” section. The x-axis shows the ApoE concentrations (in M) on a logarithmic scale