M133 Tregs, but not bulk Tregs proliferate and are recruited to the brains of rJ2.2-infected mice.

<p>(<b>A</b>) Blood was obtained from B6-Foxp3^gfp and M133 Tg-Foxp3^gfp mice and analyzed for presence of M133-specific Tregs and Tconv using I-A^b/M133 tetramers. Representative plots after gating on CD4 T cells are shown. (<b>B</b>) Experimental design. Bulk and M133 Tregs were purified by flow cytometry from the spleen and LNs of Foxp3^gfp and M133 Tg-Foxp3^gfp mice, respectively, mixed at a 1∶1 ratio and labeled with Violet. A total of 3×10⁵ cells were transferred to CD45/Thy1 congenic mice one day prior to infection with rJ2.2. (<b>C</b>) Gating strategy for identification of M133 and bulk Tregs in recipient mice is shown. (<b>D</b>) Representative plots showing proliferation of cells in the indicated tissues at day 7 p.i. The box in each panel indicates cells that have proliferated. N.D., not detectable. Percentages of divided cells are shown. (<b>E</b>) The ratio of M133 Treg/bulk Treg is shown. The data are representative of three independent experiments (<b>A, C, D</b>) or pooled from three experiments (<b>E</b>). (<b>F</b>) 2×10⁵ M133 or Bulk Tregs were transferred to Thy1.1 mismatched mice and expression levels of indicated markers on transferred cells in the DCLN at day 4 p.i. are shown. To analyze bulk Tregs, cells from 5 recipient mice were pooled. Data are representative of analyses of three individual recipients (M133 Tregs) and 2 pooled samples (bulk Tregs).