CD4⁺CD25⁺ T cells are the main producers of IL-10 during early <i>Brucella abortus in vivo</i> infection.

<p>(<b>A</b>) Flow cytometry measurement of IL-10 expression in splenic T cells, B cells, and macrophages from C57BL/6 IL-10 GFP-reporter mice infected with <i>B. abortus</i> 2308 for 3 and 9 days. (<b>B</b>) Representative data plot of IL-10 expression in splenic T cells (CD3), B cells (B220), and macrophages (CD11b⁺F4/80⁺ cells) from C57BL/6 IL-10 GFP-reporter mice. (<b>C</b>) Flow cytometry measurement of IL-10 expression in splenic CD8⁺ T cells and CD4⁺ T cells from C57BL/6 IL-10 GFP-reporter mice infected with <i>B. abortus</i> 2308 for 9 days. (<b>D</b>) Flow cytometry measurement of IL-10 expression in splenic CD4⁺CD25⁺ T cells and CD4⁺CD25⁻ T cells from C57BL/6 IL-10 GFP-reporter mice infected with <i>B. abortus</i> 2308 for 9 days. (<b>E</b>) Representative data plot of IL-10 expression in splenic CD4⁺CD25⁺ (upper panel) and CD4⁺CD25⁻ (lower panel) T cells from C57BL/6 IL-10 GFP-reporter mice. Values represent mean ± SEM. n = 4. (*) represents P<0.05 relative to uninfected control (day 0), (**) represent P<0.05 relative to day 3 infection for (<b>A</b>), relative to CD8⁺ day 9 infected for (<b>C</b>) and relative to CD4⁺CD25⁻ for (<b>D</b>) using unpaired t-test statistical analysis. FMO = fluorescence minus one.