Cell autonomous IL12 signaling is required for expansion and TSLEC vs. TMPEC formation while IFNγ signaling affects TEM vs. TCM formation in Chlamydia-specific CD8+ T cells. CD90.1 C57BL/6 mice received CD90.2 wild-type (WT), IL12Rβ−/− (A–C), or IFNγR−/− (D–F) NR23.4 one day before i.v. infection with C. trachomatis. (A, D) NR23.4 cell numbers in the spleen on day 7and 14 p.i., (B) TSLEC % and TMPEC % among NR23.4 cells on day 7 p.i., (C) TEM % and TCM % among NR23.4 cells on day 14 p.i., (E) TSLEC and TMPEC NR23.4 cell numbers on day 7 p.i., and (F) TEM and TCM NR23.4 cell numbers on day 21 p.i. are shown. Data are representative of two experiments, each with 5–6 mice per group.