Figure 1.

Only High-Affinity T Cells Expand in Listeria-Immune Mice

(A) Schematic illustration of the Experimental Procedures. Naive controls and C57BL/6 mice infected with wild-type Listeria (Lm-WT) received 10⁴ naive OT-1 4 weeks later and the indicated Listeria strains.

(B) Frequency of OT-1 T cells among peripheral blood CD8⁺ T cells 6 days after infection. Numbers indicate the ratio of OT-1 T cells in naive and Lm-WT immune hosts.

(C) Naive or Lm-WT immune mice grafted with 2.5 × 10⁵ CFSE-labeled OT-1 cells and infected with Lm-N4 or Lm-T4. CFSE dilution among splenic OT-1 (filled histogram) was measured 78 hr later. Dashed lines are unlabeled host CD8⁺ T cells. Data are representative of three (B) or two (C) independent experiments with three to five mice per group.

(D) Naive or Lm-WT infected Rip-mOva mice were 4 weeks later engrafted with low-affinity H-2K^b/Ova-specific OT-3 TCR transgenic T cells and then infected with Lm-N4. Blood glucose levels were determined 8 days later. Statistical analysis are unpaired Student’s t tests with ^∗∗p < 0.01 and ^∗∗∗∗p < 0.0001.