NK cells interact with DCs in draining LNs in a CXCR3-dependent fashion. GFP-CXCR3^+/+ (WT) and CMTMR-labeled CXCR3^−/− (KO) NK cells were infused i.v., and cellular interactions in the draining LNs were imaged by 2P-IVM 24 h after transfer during 1 h. (A) Interaction incidence; (B) experimental velocities and individual cellular mean velocity distribution; (C) mean experimental arrest coefficients and cellular arrest coefficient distribution; (D) mean experimental interaction and individual interaction times between WT or CXCR3^−/− NK cells and CD11c⁺ DCs. Data represent mean of individual animal (n = 7) or are pooled from 4 separate experiments. **, P < 0.01; ***, P < 0.001, Student’s t test.