Fig. 2.

Effect of stressed innate immune cells on melanocyte function. IFNγ production by sorted NK and ILCs from blood of healthy control (c, n = 6–10) and vitiligo (v, n = 6–10) subjects following in vitro stimulation with H₂O₂ (0.1–10 μM) (a), HMGB1 (250–1000 ng/ml) (b) or HSP70 (TKD, 250–1500 ng/ml) (c) for 24, 48 or 72 h. The effect of exogenous IFNγ (50 ng/ml) on CXCL4, CXCL9, CXCL10, CXCL11 mRNA (d) and CXCL9, CXCL10 protein (e) production by healthy (n = 4–7) and vitiligo melanocytes (n = 7–9). In f chemokine and IFNγ production was measured 24 h post stimulation of healthy (white bars, n = 4) or vitiligo (grey bars, n = 4) melanocytes with patient’s own autologous NK or ILCs (alone or in combination) which were pre-stressed with H₂O₂ for 48 h before addition of innate cells to patients own melanocytes. Positive control condition represents melanocytes directly pre-stimulated with IFNγ (50 ng/ml) for the same duration of time. PCR results are normalized to house-keeping gene SB and expressed as fold change in expression relative to the pool of healthy skin samples. Results are shown as individual dot plots with a line either at median (a–c) or at mean ± SEM (e, f)