Extended Data Fig. 8: Details of scRNA-seq/scTCR-seq data analysis and Kaede mice experiments regarding the positioning of blood CCR8⁺ T_reg cells.

a–d, UMAP representations of cells from scRNA-seq/scTCR-seq, showing clusters and cell type annotation next to gene expression and signature values underlying the annotation. Data correspond to blood T_reg cells from TCR Donor 6 (sample 28; a), blood CD45RO⁺ T_reg cells from TCR Donor 6 (sample 29, b), blood T_reg cells from TCR Donor 7 (sample 24, c) and blood CD45RO⁺ T_reg cells from TCR Donor 7 (sample 25, d). Blood CCR8⁺ T_reg signature 1 defines blood CCR8⁺ T_reg cells against blood CD45RA⁺ T_reg cells. Blood CCR8⁺ T_reg signature 2 defines blood CCR8⁺ T_reg cells against blood CD45RO⁺ (memory) T_reg cells. For details regarding the annotation, see the Methods section. e, Stacked bar charts showing TCR clonotype sharing between blood CD45RA⁺ T_reg cells, skin T_reg cells and blood CCR8⁺ T_reg cells. Bar sections indicate the percentage of cells belonging to a particular clonotype. Connections between bar sections indicate that a clonotype was found in two cell types. All clonotypes that appear in skin T_reg cells and contain at least one TCR-α and TCR-β chain are shown (271 clonotypes from TCR Donor 6, 602 clonotypes from TCR Donor 7). f, Percentages of skin T_reg cell clonotypes that were also found among blood CD45RA⁺ T_reg cells and blood CCR8⁺ T_reg cells. g, Kaede-green and Kaede-red expression in skin-draining-lymph-node-derived T_reg cells of Kaede mice 6 days after photoconversion of skin. Cells were pre-enriched for CD25 and gated on size, viability, TCR-β, CD4, CD25 and GITR. Concatenated data of 7 mice. h, CCR8 expression was measured in T_reg and T_conv cells 6 days after light exposure of skin of Kaede mice. Cells were harvested from LN and enriched for CD25 expression. Shown here are the T_conv cells present in CD25-enriched fractions, results for T_reg cells are shown in the main figure. Concatenated data of 7 mice. Data are representative of two or more independent experiments with two or more individual donors/mice.