FIGURE 2.

Foreign Ag-specific effector and memory T cells up-regulate ThPOK expression during an infection. Left panels, ThPOK^wt/gfp and ThPOK^wt/wt mice were infected with LCMV Armstrong. T cells specific for the LCMV-derived GP₃₃ epitope in the spleen were identified using D^b/GP₃₃ tetramer and anti-CD8 staining at 6, 8, and >100 days postinfection and 5 days after rechallenge of immune mice (>100 days after the primary infection) with recombinant L. monocytogenes expressing GP₃₃. The numbers indicate the percentage of tetramer-positive cells among CD8 T cells in ThPOK^wt/gfp mice. Right panels, ThPOK/GFP expression in D^b/GP₃₃ tetramer-positive CD8 T cells was determined by flow cytometry. Shaded histograms represent ThPOK^wt/wt tetramer⁺ cells. Numbers indicate the GFP MFI for ThPOK^wt/gfp cells. Results are representative of three independent experiments.