Figure 5. Radiation induces an increase in splenic regulatory T cells with a decrease in T cell proliferation.

Mononuclear cells were obtained from the spleen of sham or gamma irradiated (2 Gy) mice at the indicated times pre and post irradiation. Cells were analyzed for regulatory T cells (CD4⁺, CD25⁺, FoxP3⁺) and expressed as percent of total CD4⁺ T cells (A) or CD25 bead depleted or not and labeled with CFSE and stimulated with plate bound anti-CD3 (B). The number of cells that proliferated was calculated, as described [19]. Five mice per time point were analyzed and data are presented as mean +/− SEM. Statistical significance compared to pretreatment was determined by Student’s t-test, * = p<0.05.