Figure 3.

Human skin is the principal site of CCR8-expressing lymphocytes and NK cells. Protein expression analyses demonstrate a predominance of CCR8⁺ cells among lymphocytes, amounting to 50% of all immune cells present in human skin. Of these, CD4⁺ and CD8⁺ conventional αβ T cells and Treg cells make up >90%. CCR8⁺ immune cells are rare in peripheral blood and share the subset diversity with human skin CCR8⁺ immune cells (except for NK cells). Numbers represent fractions of CCR8⁺ cells expressed as the mean percentage of total lymphoid cells (T and B cells, ILCs) out of n = 3–12 independent experiments with skin tissue or blood samples from >20 individual donors ([77,78,79] and unpublished studies).