LPS induces B-1CDP differentiation and proliferation.

<p>A) Analysis of B-1 cell purification and CFSE⁺ staining. B-1 cells were obtained from the total peritoneal cells based on the selection of CD19⁺CD23⁻ cells as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034570#pone.0034570.s001" target="_blank">Figure S1</a>. The first dot plot represents the B-1 cell gate selected to perform cell sorting. The second dot plot illustrates B-1 cells after cell sorting. Subsequently, these cells were subjected to CFSE staining as demonstrated in the last dot plot. B) Analysis of expression of CD19 and CD23 by peritoneal lymphocytes confirms the transfer of B-1 cells to BALB/<i>Xid</i> mice. B-1 cells are almost absent in BALB/<i>Xid</i> and BALB/<i>Xid</i>+LPS mice but are present in significant numbers in BALB/<i>Xid</i>+B-1 and BALB/<i>Xid</i>+B-1+LPS mice, indicating the efficiency of the B-1 cell transfer. C) Absolute number of B-1 cells (CD19⁺CD23⁻CD11b⁺) in the peritoneal cavity of BALB/<i>Xid</i> (□) and BALB/<i>Xid</i>+B-1 (▪) after LPS or saline (−) injection. p<0.001 when the LPS-stimulated group is compared to the non-stimulated group. D) Analysis of the presence of B-1CDP (CFSE⁺ cells) in the peritoneal macrophage population (CD19⁻CD11b⁺F4/80⁺) from BALB/<i>Xid</i>, BALB/<i>Xid</i>+B-1, BALB/<i>Xid</i>+LPS and BALB/<i>Xid</i>+B-1+LPS mice. E) Absolute number of peritoneal macrophages (CD19⁻CD11b⁺F4/80⁺) from BALB/<i>Xid</i> mice (□) and BALB/<i>Xid</i>+B-1 mice (▪) after LPS or saline (−) injection. * p<0.01 when the indicated group is compared to all groups. The results are representative of two independent experiments using 5 mice per group per experiment.