Selective expansion of splenic immune cell subsets in response to FPI. (A) The number of viable cells in the spleens (cellularity) of C57BL/6 mice 24 hours following sham surgery or FPI. TBI significantly increased the number of viable cells. (B) The number of B cells (B220+) showing a trend toward B cell expansion after FPI that does not reach significance. However, treatment with CAP significantly reduced B cells after FPI. (C) Analysis of T cells (CD3+) revealed a significant expansion after FPI that is significantly reduced following CAP treatment. (D) A subset of CD3+ T cells, CD4+ T cells (CD3+CD4+), are also significantly elevated after FPI. This elevation is significantly reduced following CAP treatment. (E) Identification of Tregs (CD3+CD4+CD25HiFoxP3+) also revealed a significant increase in this cellular population after TBI. Similar to other T cell populations, this population is also significantly decreased after CAP treatment. (F) A similar pattern of FPI-induced increase is observed for γδ T cells (CD3+γδ-TCR+) and this increase is significantly reduced by our CAP treatment. (G) Analysis of CD8+ cytotoxic T lymphocytes (CD3+CD8+) also revealed a significant increase after FPI that is significantly reduced with our CAP treatment. (H) Alternatively, no significant differences were observed for activated CD4+ T cells (CD3+CD4+CD25+FoxP3−) in the spleens of C57BL/6 mice 24 hours following sham surgery or FPI. Sham + vehicle (N = 6); sham + CAP (N = 5); FPI + vehicle (N = 7 WT); FPI + CAP (N = 6). The symbol * indicates P < 0.05.