Identification of splenic IL-10-producing CD1d^highCD5⁺ Breg population induced by <i>B. microti</i> infection.

<p>Splenocytes were isolated from uninfected mice and at days 7, 11, and 14 after <i>B. microti</i> infection. (A) Representative flow cytometric data shows the frequency of CD1d^high B cells among gated CD5⁺CD19⁺ B cells. Bar graph indicate the mean mean percentages ± the standard deviation of CD1d^high CD5⁺CD19⁺ B cells in one representative experimental group consisting of five mice. (B) To examine the capacity of <i>B. microti</i> infection to induce IL-10-producing CD1d^highCD5⁺ Bregs, splenocytes isolated from infected or uninfected mice were stained with antibodies against CD19, B220, CD1d, CD5, and IL-10. The gating strategy used to identify IL-10-producing CD1d^highCD5⁺ B cell is also depicted. (C) Bar graphs indicate the mean percentages ± the standard deviation of splenic CD1d^highCD5⁺B220⁺CD19⁺ B cells that produced IL-10 in one representative experimental group consisting of five mice. *<i>P</i><0.01 and **<i>P</i><0.001 compared with the group of uninfected mice. Results presented were obtained by analyzing cells from individual mice and represent five independent experiments.