Normal B-cell motility and distribution in the absence of CCR7 and CXCR4 signaling. (A) Chemotaxis of WT, CXCR5^−/−, and CCR7^−/− B cells toward CXCL13 and CCL21 (100 nM). Data are pooled from duplicates of 2 independent experiments and shown as mean ± standard error of the mean. *P < .05; ***P < .001 (analysis of variance). (B) Chemotaxis of WT B cells to 100 nM CXCL12 in the presence or absence of NIBR1816 (10 µM). Data are from 1 experiment in duplicates. (C) Example of 2-P microscopy image (top left panel) and microenvironmental classification (top right panel) in a plt/plt PLN. Individual WT (bottom left panel) and CXCR5^−/− (bottom right panel) B-cell tracks are depicted. Scale bar, 50 µm. (D) Percentage of microenvironmental track distribution in plt/plt PLNs as determined by 2-P microscopy. (E) Speeds of WT and CXCR5^−/− B cells in T-cell area and B-cell follicles in plt/plt PLNs. Each dot represents an individual track. The red bar represents the mean. (F) Percentage of microenvironmental track distribution in NIBR1816-treated plt/plt PLNs as determined by 2-P microscopy. (G) Speeds of WT and CXCR5^−/− B cells in T-cell area and B-cell follicles in NIBR1816-treated plt/plt PLNs. Each dot represents an individual track. The red bar represents the mean. Data in D and E are pooled from 3 mice, 10 image sequences, and 558 WT and 263 CXCR5^−/− B-cell tracks. Data in F and G are from 3 mice, 5 image sequences, and 1168 WT and 414 CXCR5^−/− B-cell tracks. Fo, B-cell follicle; H, HEV; T, T-cell area. **P < .01, ***P < .001.