Fig. 6: Platelets from NSCLC patients show increased PD-L1 protein levels upon activation.

a Correlation between platelet-derived PD-L1 (pPD-L1) and platelet activation (CD62P expression) in 128 NSCLC patients. Each dot represents a single patient. b Platelets from a NSCLC patient assessed by transmission electron microscopy. PD-L1 stained with post-embedding immunogold-labeling. Upper and lower right, PD-L1 gold particles densely accumulate in α-granules. Scale bar left 1 µm, right 100 nm (n = 1). c, d Changes in CD62P (c) and the pPD-L1 (d) levels upon platelet stimulation with 10 µM TRAP-6 for 2 min in NSCLC patient samples (n = 128). Boxes represent median and 25th to 75th percentiles, whiskers are minimum to maximum. Statistical significance was calculated by two-tailed Mann–Whitney test. e CD62 expression change (ΔCD62P) in the different pPD-L1 quartile groups identified in unstimulated platelets of NSCLC patients (n = 128). Data are mean ± SEM. Statistical significance was calculated using Kruskal–Wallis test. f pPD-L1 expression change (ΔpPD-L1) in the different pPD-L1 quartile groups identified in unstimulated platelets of NSCLC patients (n = 128). Data are mean ± SEM. Statistical significance was calculated by Friedman and Dunn’s multiple comparisons test. g CD62P expression change (ΔCD62P, CD62P in stimulated platelets in % – CD62P in unstimulated platelets in %) after platelet activation with 10 µM TRAP-6 (n = 24), 2.5 µM ADP (n = 24), or 5 µg/ml collagen (n = 24). Boxes represent median and 25th to 75th percentiles, whiskers are minimum to maximum. h pPD-L1 expression change ΔpPD-L1 (pPD-L1 in stimulated platelets in % – pPD-L1 in unstimulated platelets in %) in NSCLC patients after platelet activation. Statistical significance was calculated by Kruskal–Wallis test. Boxes represent median and 25th to 75th percentiles, whiskers are minimum to maximum. i Correlation between pPD-L1 expression in unstimulated platelets of 128 NSCLC patients and the ΔpPD-L1 upon platelet stimulation with 10 µM TRAP-6. Each dot represents a single patient. j Heatmap showing the calculated ΔpPD-L1 depending on the CD62P activation ranges (y-axis) and the quartiles of pPD-L1 level (x-axis) calculated in pooled data from 128 NSCLC patients. For details of subsampling and calculation used, see Methods and Supplementary Fig. 4. k Adjusted pPD-L1 levels in all 128 NSCLC patients upon calculated platelet pre-activation ranges (by CD62P expression level). a, i Correlation was determined by simple linear regression analysis. Source data are provided as a Source Data file.