Fig 2: Adoptive WT B cell transfer improves Cd6−/− mice survival to CLP-induced sepsis(A) Cd6−/− mice were i.p. pre-treated overnight with 107 cells/mouse of negatively sorted (GR1-CD11c-CD3-NK1.1-) spleen B cells from WT or Cd6−/− mice, before CLP induction. Percent average of mouse survival is represented over time. ∗p < 0.05 (Gehan-Breslow-Wilcoxon test).(B) Cd6−/− mice were i.p. pre-treated overnight with negatively sorted (GR1-CD11c-CD19-B220-) spleen T and NK cells (107 cells/mouse) from WT mice, before CLP induction. Percent average of mouse survival is represented over time. ∗p < 0.05; ∗∗p < 0.01 (Gehan-Breslow-Wilcoxon test).

Fig 3: Cd6−/− mice show poor prognosis markers post-CLP induced sepsis(A) Bacterial load post-CLP. Bacterial burden in peritoneum (left) and spleen (right) from WT and Cd6−/− mice was assessed at 24 h post-CLP induction. Data are expressed as mean ± SEM of CFU/g or CFU/mL. A representative experiment of 3 independently performed experiments is shown. ∗p < 0.05; ∗∗p < 0.01 (Mann-Whitney test).(B) Cytokine levels post-CLP. Plasma and peritoneum IL-6 and tumor necrosis factor aloha (TNF-α) levels from WT and Cd6−/− mice were assessed by ELISA at 24 h post-CLP induction. Data are expressed as mean ± SEM. A representative experiment of 3 independently performed is shown. ∗p < 0.05; ∗∗p < 0.01 (Mann-Whitney test).(C) Peritoneal neutrophil infiltration pre- and post-CLP. Percentage (left) and absolute number (right) of neutrophil (Gr1+F4/80−) in peritoneum from WT and Cd6−/− mice was assessed under basal conditions and 24 h post-CLP. A representative experiment of 3 independently performed is shown. ∗p < 0.05 (Mann-Whitney test).

Fig 4: Steady state Cd6−/− mice show low spleen B1a and MZB cell levels(A) Percentage and absolute numbers of peritoneal B (CD19+) and B1a (CD19+CD11b+CD5+) cells as assessed by flow cytometry. Mean ± SEM is indicated. ∗p < 0.05 (Mann-Whitney test).(B) Percentage and absolute numbers of spleen B (CD19+), B1a (CD19+CD5+), and MZB (B220+CD21+CD23−) cells as assessed by flow cytometry. Mean ± SEM is indicated. ∗p < 0.05; ∗∗p < 0.01 (Mann-Whitney test).

Fig 5: Cd6−/− mice show higher susceptibility to different experimental models of bacterial sepsisWT and Cd6−/− mice were subjected to CLP-induced peritonitis (left), E. coli-induced peritonitis (9 × 106 CFU/mouse, i.p.) (middle) or K. pneumoniae-induced pneumonitis (9 × 108 CFU/mouse, i.n.) (right). Percent average of mouse survival is represented over time. ∗p < 0.05; ∗∗p < 0.01 (Gehan-Breslow-Wilcoxon test).