Figure 2.
Marked dependence of Treg vs. Tcon cells on OXPHOS. A) Tcon cells were labeled with CFSE and activated with CD3 mAb plus APC for 72 hours. Addition of 2.5 μM rotenone, an inhibitor of complex I of the mitochondrial respiratory chain, prevented T cell proliferation. B and C) C57BL/6 Tregs were added to CFSE-labeled Tcon cells stimulated as in A. B) Percentage of Tcon cell proliferation is indicated. Less Tcon cell proliferation indicates increased Treg suppression. Treatment with 200 μM etomoxir and 50 nM rotenone weakened Treg suppressive function without affecting Tcon cell proliferation; higher doses impaired Tcon cell proliferation as well. Data are representative of 3 or 4 independent experiments. C) Pooled rotenone (n = 7) and etomoxir (n = 4) treated Treg suppression data normalized to vehicle control. Paired Student’s t test, *P < 0.05, **P < 0.01.