Fig. 1

HIF-1α inhibitor echinomycin increases regulatory T cell development during alloantigen-specific CD4 T cell responses ex vivo. Purified splenic CD4 T cells from C57BL/6 mice were cocultured with BMDCs of Balb/c mice. On days 0 (immediately after coculture), 3, and 6 of culture, cells were recovered for intracellular staining and flow cytometry analysis. Representative plots and frequencies of intracellular Foxp3, IL-17, or IFN-γ expression in CD4 T cells on day 6 are shown in a. Numbers in flow cytometry plots represent mean ± SD frequency (%) of Foxp3⁺, IL-17⁺, or IFN-γ⁺ cells in CD4 T cells. Absolute numbers of Foxp3⁺, IL-17⁺, or IFN-γ⁺ CD4 T cells per well on days 0, 3, and 6 are shown in b. c Proliferation of CD4 T cells cultured alone (T), with allogeneic DCs (T + DC), or with allogeneic DCs at the presence of echinomycin (T + DC + echinomycin), on day 5 of culture is indicated by CFSE dilution analysis. Numbers in flow cytometry plots represent frequency (%) in total CD4 T cells. d Concentrations of cytokines in the supernatant on days 0, 3 and 6 of culture are shown. ND not detected in either group. Bar graphs are shown as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001. Data are representatives of three independent experiments with triplicate wells in each group