MKs presentation activates CD8⁺ T cells in vivo. MKs from WT or B2M KO mouse donors were pulsed with OVA and transfused in OT-1 or WT BL/6 mice. After 48 hours, mice were sacrificed and the percentage of activated CD8⁺ T cells was measured considering the CD69 expression in spleen (A), blood (B), and lymph nodes (C). NS, not significant. One-way ANOVA with a Tukey correction for multiple testing; n ≥ 3; mean with SD; ***P < .001; **P < .01; *P < .05; each n corresponds to an independent MK donor and recipient mouse.