Figure 1.

CCR5 expression is essential for the neuroprotective effect of Tregs against transient cerebral ischemia. Cerebral ischemia was induced by transient middle cerebral artery occlusion (tMCAO) for 60 minutes. Mice received 2×10⁶ Tregs isolated from wild type (WT) mice or CCR5^−/− donor mice. Control mice received the same number of splenocytes (Sp). Animals were euthanized at 3 days after stroke. A, Representative laser speckle imaging of cerebral blood flow (CBF) before (baseline), during (ischemia), and after MCAO (reperfusion). B, Quantification of CBF as percentages of the preischemia levels. C, Representative images of 2,3,5‐triphenyltetrazolium chloride (TTC) staining for infarct measurement. D, Quantification of infarct volume. E, Quantification of brain edema. F, Neurological score evaluated during the first 3 days after stroke. n=5/group. *P≤0.05, **P≤0.01, ***P≤0.001. CCR5 indicates C‐C chemokine receptor type 5; Treg, regulatory T cell.