Antigen-incorporated BMMCs activate antigen-specific CD4⁺ T cells. (A) Anti-OVA IgE pretreated (bottom) or untreated (top) BMMCs were incubated for 48 hours with low-dose (0.5 μg/mL; middle) or high-dose (50 μg/mL; right) OVA. BMMCs that received no OVA were used as a control (left). (B) Anti-DNP IgE pretreated BMMCs were incubated for 48 hours with DNP-HSA (50 μg/mL; top) or DNP-OVA (50 μg/mL; bottom). The BMMCs were washed and cocultured with MACS-purified CD4⁺ T cells from OT-II mice. Forty-eight hours later, CD69 was detected on CD4⁺ T cells by flow cytometry. The number in the upper right corner represents the percentage of CD69⁺CD4⁺ T cells of total CD4⁺ T cells.