High avidity Mini cells supply the inflationary T cell pool.

105 sorted low and high avidity CD45.1+ Mini CD8 T cells were adoptively transferred into naïve C57BL/6J mice prior to an i. v. infection with 5 × 106 PFU MCMVΔm157. (A) Representative contour plot showing naïve Mini CD8 T cells (left plot) and Mini cells (gated on CD8+ CD45.1+) from a day 7 infected host after adoptive transfer (right plot). The percentages within CD8 T cells are indicated. (B) Sorted high (left plot) and low avidity (right plot) Mini CD8 T cells according to M38-tetramer staining intensity are shown. (C+D) Sorted naïve high and low avidity Mini cells were exposed to various concentrations of M38316-323 peptide. The geometric means of CD25 (C) and CD69 (D) are shown as mean + SEM. (E) Percentages of M38-specific CD8 T cells were measured in the blood of mice transferred with high (left graph) or low avidity Mini cells (right graph). (F) Percentages of low and high avidity Mini cells in the lungs at day 117 post infection are shown as mean + SEM of n = 3–4 mice, representative of two independent experiments. (G) Percentages of KLRG1+ CD127- expression on Mini cells in the lungs and spleen at day 117 post infection are shown as mean + SEM of n = 3–4 mice representative of two independent experiments. (H) Staggered overlay of histograms of mean fluorescence intensities of M38-tetramer (left). Mean fluorescence intensities on low and high avidity Mini cells in the lungs at day 117 post infection are shown as mean + SEM of n = 3–4 mice representative of two independent experiments. (E-H) *pt test (F-H).