Chemokine-based CD8⁺ T cell homing to DCs. (A) MPM images of animals that were given 1.0 × 10⁷ Cell Tracker Red (red)–labeled OT-I cells in the presence or absence (untreated) of chemokine-neutralizing Abs against CCL3, CCL4, and CCL5. Images acquired 6–8 hpi with VV-Ova (nonfluorescent). MRR delineated by white lines. (B) Percentage of OT-I cells per 63× field (238 × 238 × 85 µm) located in the MRR in untreated or antibody-treated mice. Results were analyzed with an unpaired Student’s t test. (C) MPM images from the top 30 µm of the inguinal node of CD11c-eYFP mice given fluorescent-dextran (red) to label macrophages and OT-I cells (blue). Mice were given chemokine neutralizing Abs; nodes imaged at 8 hpi with nonfluorescent VV-Ova. (right) A schematic of T cell and macrophage localization after VV infection with CCR5-ligand blockade. Scale bars are shown in micrometers. (D and E) OT-I cells (red) in the MRR (green) after s.c. administration of recombinant CCL3 at 2.25 hpi with VV-SIINFEKL (nonfluorescent; E) tracks of OT-I cells in the presence (left) or absence (right) of rCCL3 2–3 hpi. Tracks are colored according to mean track speed (slowest [purple) to fastest [red]). (F) Distribution of CCR5KO OT-I cells (red, left) or WT OT-I cells (red, right) 6 hpi with VV-NP-S-eGFP (green). (G) CCR5KO OT-I cells (red) in the MRR (visualized using the intrinsic autofluorescence of macrophages) at 6 hpi (virus=green, collagen=blue) (H) CD69 expression by LN OT-I cells 15 hpi with VV-Ova in the presence or absence of chemokine-neutralizing Abs. Data were averaged from three independent experiments normalized using the highest mean fluorescence intensity in an individual experiment as 100. (I) IFN-γ production by OT-I cells in the node 48 hpi with VV-Ova. Data were compiled from two independent experiments and normalized to the highest mean fluorescence intensity per experiment. (J) Same as described in H, but with CCR5KO OT-I cells. All experiments were performed at least twice with three to six mice/group.