CD45.1⁺ B6 mice receiving naive CD45.2⁺ CD90.2⁺ OT-II cells i.v. with or without CD45.2⁺CD90.1⁺CD90.2⁺ OT-II Trm i.n. were then challenged i.n. with 50 μg of FITC-OVA. (A) Representative staining to identify donor OT-II subsets. (B) Number of naive OT-II responders in lungs after 4 days. (C) Representative IFN-γ and IL-2 staining in mice without or without Trm, and frequencies of IFN-γ⁺ cells derived from naive donors; n = 4/group; 1 of 3 experiments. Separate mice received naive OT-I cells with or without OT-II Trm. (D and E) Number of OT-I responders in lungs (D) and IFN-γ⁺ OT-I cells 4 days after FITC-OVA administration (E); n = 5/group; 1 of 2 experiments. (F) Representative CD69 expression by Trm 20 hours after i.n. challenge with 50, 0.5., or 0.05 μg of FITC-OVA. (G and H) Representative Ki67 and CFSE expression by naive OT-II responders in dLN of mice harboring OT-II Trm given 0.5 μg FITC-OVA or PBS (left) and numbers of CFSE^loKi67^hi cells in dLN of mice harboring Trm or not at day 3 (right) (G), and in lungs at day 4 (H); n = 4/group; 1 of 3 experiments for each time point. Mice receiving naive donor cells and Trm were treated with CXCR3 blocking or control Ab prior to FITC-OVA administration. (I) Number of cells derived from naive OT-II (left) and OT-I (right) donors in lungs after 4 days; n = 3/group; 1 of 2 experiments. (J) Unprimed mice receiving CFSE-labeled naive OT-II cells with or without Trm were challenged with PR8-OVA_II. (K) Gating to identify effector cells derived from naive donors. (L) Number of CFSE^–Ki67^hi effectors at 4 dpi in stated organs; n = 7/group; pooled from 2 experiments. Student’s t test was used for pairwise comparison in all panels except H, where 1-way ANOVA with Tukey’s multiple-comparison test was used. *P < 0.05, **P < 0.01, ****P < 0.0001.