Figure 6.

Bcl11b is required for optimal generation of memory CD8 T cells after systemic infection with VacV. WT (Bcl11b^flox/flox/dLck-iCre⁻) or Bcl11b-conditional knockout (Bcl11b^flox/flox/dLck-iCre⁺) mice were infected i.p with VacV-WR (2 × 10⁵ PFU/mouse). Sixty days postinfection, splenocytes and lung cells were harvested and stained for CD8, CD44, Ki67, and B8R_20–27/k^b tetramer. (A,B) Left, representative plots of CD8/CD44 (Top Panels) and CD8⁺CD44^hi B8R_20–27/k^b-tetramer staining (Bottom Panels), gating on live cells, are shown. Percentages of activated (CD44^hi) and B8R_20–27/k^b tetramer + CD8 T cells within each gate are indicated. Right, percentages and total numbers of CD8⁺CD44^hi and B8R_20–27/k^b tetramer + cells per spleen (A) and lung (B). (C) Total numbers of B8R_20–27/k^b tetramer + cells in spleen and lung at day 8 and 60 post infection. Numbers in red indicate the fold-decrease of response between days 8 vs. 60 within each group. (D) Left, representative plots showing the percentage of CD8 T cell proliferation by Ki67 staining among CD44^hi cells in VacV-infected mice. Right, Percentages and total numbers of CD8⁺CD44^hiKi67⁺ cells per spleen and lung. Quadrant settings were based on controls, after gating on naïve CD44^lo cells in the same host. Percentages that stained positive for each marker are indicated. The results shown are representative of two separate experiments each with four mice per group. Asterisks indicate statistical significance. The p-values are <0.05 by two-tailed Student t-test (WT vs. Cko).