C. trachomatis induces impaired memory CD8+ T cells. (A) CrpA-specific CD8+ T cell numbers in the spleen of systemically infected mice on day 7 p.i are shown. (B) CrpA-specific CD8+ T cell numbers in the spleen of mice systemically infected with C. trachomatis or 2×103 PFU of VacCrpA on indicated days p.i. are shown. (C) IFNγ+ %, (D) BrdU+ %, (E) CD95 MFI, (F) CD27+ %, (G) CD122 MFI, and (H) IL18Rα MFI of CrpA-specific CD8+ T cells in the spleen on days 26–30 p.i. are shown. Data are representative of at least two experiments, each with 5–7 mice per group.