Antigen presentation capacity in SS and MF. (A) Antigen pulsing of APCs with autologous Sézary peripheral blood CD4⁺CD26⁻CD7⁻ cells (n = 3) against no antigen, keratinocyte lysate (12 μg), or allogenic Sézary skin biopsy lysate (12 μg). Positive control for proliferation was CD3/CD28 stimulated T cells. Enzyme-linked immunosorbent assay (ELISA) of supernatant from antigen presented cells for human IL-4 with a 1:1 dilution. Values are represented as fold change over APCs and T-cell negative control condition. Experiment was done in triplicate. (B) Quantification of fold change over APC and T cells for CD69 activated live CD4⁺CD26⁻ T cells across keratinocyte, skin, APC and T cells only, and CD3/CD28 bead stimulated T cell conditions. Two-tailed Student t test: ∗P < .05; ∗∗P ≤ .01. (C) Conditions similar to panel A were performed in the peripheral blood MF samples CD4⁺CD26⁻/CD7⁻ cells (n = 3) for the quantification of fold change of CD69 activated T cells. Two-tailed Student t test was performed. (D) Histogram displaying the FACs staining for CD69 (n = 3). n.s., nonsignificance.