FIG 6.

Tregs do not protect Mavs^−/− mice from lethal infection. WT and Mavs^−/− mice were infected with 100 PFU WNV s.c. Cells from peripheral lymphoid organs (A) or brains (B) were harvested at the indicated time points. The frequencies and numbers of Foxp3⁺ Tregs are shown. (C) Tregs (6 × 10⁵) were purified from Mavs^−/−/Foxp3-IRES-GFP or Mavs^+/+/Foxp3-IRES-GFP mice and adoptively transferred into Mavs^−/− mice i.v. 1 day before WNV infection. Survival was monitored daily (WT Treg, AT, n = 5; Mavs^−/− Treg, AT, n = 5). AT, adoptive transfer. (D) WT mice were infected with WNV. Cells from brains and spleens were harvested at day 10 p.i. The frequencies of E641 tetramer⁺ cells in Foxp3^- CD4 T cells and Foxp3⁺ Tregs are shown. Cells from 4 to 6 mice were pooled. The data are representative of the results of 3 independent experiments. The error bars indicate SEM.