Extended Data Figure 3: CD8⁺ T cells accumulate preferentially in the epidermidis after topical application of S. epidermidis.

a, Proportion of effector (CD45⁺ TCRβ⁺ Foxp3⁻) CD8β⁺ T cells in the epidermal and dermal compartments of the ear skin tissue 2 weeks after the first S. epidermidis topical application. b, Representative imaging volume projected along the x axis of ears from Langerin–GFP reporter mice at 14 days post first topical application with S. epidermidis. Scale bars, 30 μm. c, Numbers of CD3⁺ CD8β⁺ cells producing IFN-γ or IL-17A (after PMA/ionomycin stimulation) from normal nonhuman primate (NHP) skin (n = 8). d, Assessment of IL-17A production in the supernatant of CD8β⁺ T cells purified from the skin of mice topically associated with S. epidermidis and cultured overnight in presence of anti-CD3ε alone (Ctrl) or with IL-1α and IL-1β (+ IL-1). Bars represent the mean value ± s.e.m. (n = 3, **P < 0.01 as calculated with Student’s t-test). Results shown in a, c and d are representative of 2–3 experiments with similar results.