Figure 3.

IL-2 and IL-15 Induce Perforin and Granzyme Expression Specifically in Epidermal CD8⁺CD103⁺CD49a⁺ T Cells

(A) Representative FACS plot of perforin and granzyme B expression in relation to CD49a expression in epidermal CD8⁺CD103⁺ Trm cells with or without IL-15 (20 ng/mL) stimulation for 48 hr.

(B) Perforin (black) and granzyme B (gray) expressing cells among epidermal CD8⁺CD103⁺ Trm cells following 48 hr incubation with medium, IL-2 (20 ng/ml), IL-7 (20 ng/ml), IL-15 (20 ng/ml), IL-1β (20 ng/ml), IL-6 (20 ng/ml), IL-23 (20 ng/ml), IL-12, (50 ng/ml), IFN-α (2,000 U/ml). Mean ± SD is depicted. Kruskal-Wallis with Dunn’s multiple comparison tests.

(C) Proportion of perforin and granzyme B expressing cells among epidermal CD8⁺CD103⁺CD49a^– or CD8⁺CD103⁺CD49a⁺ Trm cells upon IL-15 stimulation (n = 12). Two-tailed Wilcoxon test.

(D) CD8⁺CD103⁺ Trm cells were sorted and stimulated with IL-15 (20 ng/ml) for 1, 2, 4, 8, or 48 hr. Mean ± SD of the increase (Δ) in perforin (left) and granzyme B (right) expressing cells among CD8⁺CD103⁺CD49a^– (inverted triangle) or CD8⁺CD103⁺CD49a⁺ (upright triangle) Trm cells as compared to unstimulated (n = 4). Two-tailed paired t test with Holm-Sidak correction. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001. See also Figure S2.