Fig. 4.

Educated NK cells mobilize dense-core secretory lysosomes. a Representative example of granzyme B and CD107a expression in self KIR⁺ and non-self KIR⁺ CD56^dim NKG2A⁻NKG2C⁻CD57⁻NK cells following stimulation with K562 cells. b Aggregated data of percent CD107a^high NK cells following stimulation with K562 cells (n = 5 donors). c Expression of granzyme B in the indicated NK cell subset after stimulation with K562. Summary of data from 4 C1/C1 donors. d Representative images of immuno-EM sections of resting (left) or sorted degranulated CD107a^high NK cells (right). Scale bar: 200 nm. e Secretory lysosome size and granzyme B content as determined by immuno-EM in resting and sorted CD107a^high NK cells after stimulation with K562. A Wilcoxon test was performed in panel (b). A non-parametric Friedman test was performed in panel (c). Whiskers show 5th to 95th percentile. Bars show the median. *p < 0.05. Red and blue box plots represent NK cells with self or non-self KIR, respectively