Proliferation of CD4⁺ T cells cocultured with autologous DCs pulsed with mIg or TT. The percentages of proliferating cells among the total CD4⁺ T-cell population analyzed after 7 days of coculture are indicated, as deduced from the relative numbers of CD4⁺ T cells with reduced intracellular concentrations of CFSE (CFSE-low). Middle graphs depict a decrease in proliferation of CD4⁺ T cells when antigen-pulsed DCs were preincubated with anti–MHC class II antibodies (ab), in comparison with preincubation with isotype control (right graphs) or without antibody (left graphs).