Virus-specific CD8⁺ T cell interactions with CD11c⁺ microglia are MHC I dependent. (A) Two-photon imaging experiments were performed in CD11c-YFP⁺ carrier mice 12 d after adoptive transfer of memory splenocytes containing OFP⁺ CD8⁺ P14 T cells. Mean track velocities, arrest coefficients, and meandering factors are shown for OFP⁺ P14 T cells that either did or did not establish contact with CD11c-YFP⁺ microglia in time lapses examined over a 1-h time interval (n = 4 mice per group). (B) Two-photon analyses of OFP⁺ P14 T cells interacting with CD11c-YFP⁺ cells were performed on brain slices incubated with MHC I blocking or isotype control antibodies at day 12 after immunotherapy (n = 4 mice per group). Motility parameters are shown for P14 T cells that contacted CD11c⁺ microglia for >30 s during the length of the track. All data in this figure are representative of two independent experiments. Colored dots represent individual T cells, and the mean ± SD for each group is depicted with horizontal black lines. *, P < 0.05.