B6.lpr DN T cell- secreted IFNγ is required, but APCs are not, for inhibition of alloreactive CD4⁺ T cell proliferation in vitro.

<p><b>A.</b> In varying ratios, B6.<i>lpr</i>.IFNγ^−/− or B6.<i>lpr</i>.IFNγ^+/+ DN T cells were cultured with CFSE-labelled B6. Thy1.1 CD4⁺ T cells in the same conditions as Fig. 3B for 5 days. CFSE histograms, gated on Thy1.1⁺CD4⁺ cells, from one of three independent experiments are shown. Numbers inside histograms reflect the percentage of cells in the CFSE^hi gate. <b>B.</b> Compiled data from three independent experiments are shown. Two-way ANOVA p = 0.0004. <b>C.</b> In varying ratios, B6.<i>lpr</i> DN T cells were cultured with CFSE-labelled B6. Thy1.1.IFNγR^−/− or B6. Thy1.1.IFNγR^+/+ CD4⁺ T cells in the same conditions as Fig. 3B for 5 days. Two-way ANOVA p = 0.93. <b>D.</b> In varying ratios, B6.<i>lpr</i>.IFNγ^−/− or B6.<i>lpr</i>.IFNγ^+/+ DN T cells were cultured with CFSE-labelled B6. Thy1.1 CD4⁺ T cells for 3 days with soluble anti-CD28 mAb and plate-bound anti-CD3 mAb. CFSE histograms from one of two independent experiments with similar results are shown. <b>E.</b> Data from two independent experiments are shown; two-way ANOVA p = 0.0028.