Figure 6.

CD85k⁺ Treg cells display dynamic expression of co-inhibitory receptors in vivo. Rag1^−/− mice were reconstituted i.v. with 5 × 10⁵ CD8⁺ and 5 × 10⁵ CD4⁺Foxp3-GFP⁻ effector T cells together with 10⁵ naïve, CD85k⁺, or CXCR3⁻CD85k⁻ Treg cells sorted from naïve or LCMV-infected (days 12–14) Foxp3-GFP KI reporter mice, respectively. (A) 10 days post transfer, total numbers of splenic CD4⁺Foxp3⁻ effector T cells were determined and IFN-γ production upon restimulation with PMA/Ionomycin was measured by flow cytometry. (B,C) In the same samples as in (A), expression of co-inhibitory receptors in CD4⁺Foxp3⁺ Treg cells was analyzed and (C) compared to initial levels of the markers within the specific Treg subset prior to transfer. Data in summary graphs (A) are displayed as mean ± SD, n = 2–4 (pooled data from two independent experiments). (C) mean value of pre = 5 biological replicates and post = 4 biological replicates.