Low affinity–primed T cells contribute to early elimination of target cells outside lymphoid priming tissue. (A) Prf1-deficient mice received s.c. injections of N4-, Q4-, and T4-pulsed DCs into hind and unpulsed DCs into front footpads, followed by i.v. transfer of 10⁴ GFP⁺ OT-I T cells 24 h later. At 60 or 84 h after T cell transfer, mice received a second injection of mixed fluorescently labeled unpulsed and N4-, Q4-, or T4-pulsed DCs into hind and front footpads. Draining reactive popliteal and nonreactive brachial LNs were isolated 24 h later to determine DC elimination as in Fig. 2. (B and C) Ratio of unpulsed and pulsed DCs (B) and per-cell killing efficacy (C) in popliteal LNs at 84 and 108 h after T cell transfer. (D and E) Ratio of unpulsed and pulsed DCs at 84 and 108 h (D) and per-cell killing efficacy (E) in brachial LNs at 84 h after T cell transfer. (B–E) Data are pooled from two independent experiments with total of five to eight LNs isolated from three to four mice per condition. Statistical significance was analyzed by Kruskal-Wallis tests with Dunn’s posttest. *, P < 0.05; **, P < 0.01; ***, P < 0.001.