Figure 4.

CD8 T cells lacking Bcl11b are defective in lytic activity and anti-viral cytokine production after systemic infection with VacV. WT (Bcl11b^flox/flox/dLck-iCre⁻; n = 8) or Bcl11b-conditional knockout (Bcl11b^flox/flox/dLck-iCre⁺; n = 7) mice were infected i.p with VacV-WR (2 × 10⁵ PFU/mouse). Eight days postinfection, splenocytes and lung cells were harvested and stimulated with B8R peptide for 8 h and subsequently stained for CD8α, CD107a, and intracellular IFN-γ and TNF. Representative plots for CD107a (A), IFN-γ (B), TNF (C), CD107a/IFN-γ (D), CD107a/TNF (E), and IFN-γ/TNF (F) staining in gated CD8⁺CD44⁺ T cells. Numbers indicate percentages of positive cells or mean fluorescence intensity (MFI in red) within the gated population. Gates were based on controls, after gating on CD44^lo cells in the same host as well as using infected cells that were not stimulated with peptide and uninfected cells stimulated with B8R peptide for cytokine analysis (data not shown). The results shown are representative of two separate experiments each with three to four mice per group. The p-values are <0.05 by two-tailed Student t-test (WT vs. Cko).