All conventional peritoneal cavity B1 cells show D6-dependent CCL2^AF647 uptake. (A) Flow cytometric fractionation of WT peritoneal cavity CD19⁺ cells using anti-CD11b and anti-CD5. (B) Overlaid CCL2^AF647 uptake profiles of WT (black) and D6-deficient (KO; gray) peritoneal cavity CD19⁺ cell subsets. Bar graph shows average MFI ± SEM of CCL2^AF647 uptake by each subset. (C) Overlaid flow cytometry plots of CCL2^AF647 uptake by WT CD19⁺CD11b⁺ peritoneal cavity cells after incubation at 4°C (black) or at 37°C in the presence (gray) or absence (dashed) of a 10-fold excess of unlabeled CCL22. (D) Expression of D6 mRNA in FACS-sorted B-cell populations (pooled from 4 WT mice). B1a/b are CD19⁺CD11b⁺ cells. Expression by CD19⁺CD11b⁻CD5⁻ (11b⁻5⁻) cells was set to 1. (E) Overlaid CCL2^AF647 uptake profiles of WT (black) and KO (gray) peritoneal cavity T cells (CD19⁻CD11b⁻CD5^hi) and macrophages (CD19⁻CD11b⁺CD5⁻). Flow cytometric profiles are representative of data generated from > 3 mice per genotype per experiment, with experiments repeated at least 3 times.