Preincubation of H11 cells with CpG enhances phagocytosis and activation of macrophage and DCs. (A) Ax700-labeled CpG/H11 or H11 tumor cells were added to macrophage-containing wells for 24 hours. Nonadherent cells were washed off the plate, and the remaining macrophages were harvested and analyzed by flow cytometry. Phagocytosis was assessed by the percentage of Ax700⁺F4/80⁺ cells (top row). (B) Activation was assessed by expression of CD40 and CD80 (bottom row). Plots are representative of 3 independent wells per condition. (C) Data from 3 independent wells shows the percentage of CD40⁺CD80⁺ macrophages from either wild-type C57BL/6 or TLR9KO mice after incubation with CpG/H11 or H11. *P < .05 (Student unpaired t test). (D) Bone marrow–derived DCs were assayed for phagocytosis and activation as above. Data from 3 independent wells show the percentage of CD40⁺CD80⁺ DCs from either wild-type C57BL/6 or TLR9KO mice after incubation with CpG/H11 or H11. ***P < .0001. All plots are gated on live cells.