Fig. 5: CD69 expression and apoptosis of activated CD8⁺ T cells.

Activated CD8⁺ T cells were co-incubated with exosomes isolated from plasma of HNSCC patients at defined time-points. Activation (a) and apoptosis (b) of CD8⁺ T cells were determined by flow cytometry using fluorochrome-conjugated antibodies against CD69 and annexin/propidium iodide staining, respectively. Results are shown as percentage of CD69 positive cells (a) and annexin positive cells (b). All results are plotted as box-and-whisker blots representing the median value, the 25th and 75th quartiles and the range from n = 10 replicates (control), n = 10 (pre-OP), n = 5 (post-OP, non-recurrence, recurrence) HNSCC patients. All p-values were determined by Mann–Whitney test, with *, **, *** and **** corresponding to p ≤ 0.05, p ≤ 0.01, p ≤ 0.001 and p ≤ 0.0001, respectively. Asterisks above or below boxes indicate the significance compared to the control.