Figure 1

Frequencies of NK cells in melanoma patients and healthy controls. (A) Representative dot plots of the gating strategy used. Lymphocytes were selected using forward (FSC) and side scatter (SSC), afterwards doublets were gated out and live cells were selected. A series of negative selections was performed, first gating out DCs, monocytes and B cells using a lineage cocktail, next T cells and ILCs were gated out using CD3 and CD127. Total NK cells were positively selected using CD56 (total NK cells), this population can be further divided into CD56^bright, CD56^dimCD16⁺ and CD56^dimCD16⁻ NK cells. (B) Histograms of the frequencies of total NK cells, CD56^bright, CD56^dimCD16⁺ and CD56^dimCD16⁻ NK cells, as measured by flow cytometry in PBMC samples of 28 melanoma patients and 13 healthy donors. Frequencies of the patients with values lower than the median are indicated in red, and those higher than the median are indicated in grey. (C) Kaplan-Meier curves of overall survival, of patients with high (grey) vs. low (red) percentages of total NK cells, CD56^dimCD16 + , CD56^dimCD16⁻ and CD56^bright NK cells, with the median as cut-off. (D) Absolute numbers of corresponding CD56^dimCD16⁺ and CD56^bright NK cells represented in a xy-plot. Kaplan-Meier curves of overall survival with high (grey) vs. low (red) numbers of CD56^bright NK cells, with the median as cut-off. E. Kaplan-Meier curves of progression free survival with high (grey) and low (red) frequencies and absolute numbers of CD56^bright NK cells with the median as cut-off. ns not significant, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.