TBMs accommodate the final stages of B cell apoptosis . (A) Immunofluorescence staining for activated caspase 3 (aCasp3) and TUNEL of PPs derived from WT mice. (B) Immunofluorescence staining for activated caspase 3 and TUNEL in PPs derived from PBS or DT-treated CX3CR1^DTR mice. (C) Quantification of GC to background ratio of active caspase 3 and TUNEL signals. Each dot represents a GC. Data were collected from three mice in two independent experiments. Line represents the mean. *, P < 0.05; ***, P < 0.001; ns, not significant; two-tailed Student’s t test.