Fig. 4. MHC-I presentation of cognate antigen via cross-priming and cross-decoration are required for T_RM cell maintenance.

(A) F1.OVA H-2K^b-sufficient (H-2K^b/d) or F1.OVA H-2K^b-deficient (H-2K^–/d) kidney allografts were transplanted into B6 H-2K^b-sufficient (H-2K^b/b) or B6 H-2K^b-deficient (H-2K^b–/–) recipients followed by co-adoptive transfer of 1 × 10⁶ effector OT-I cells 2 days post-transplantation. Transplant recipients were harvested on days 7 and 56 to study maintenance of CD8 T_RM cells. Flow analysis was performed after gating on extravascular graft CD8⁺ T cells as shown in Fig. S1B. n = 5–6 mice per group.

(B) Representative flow plots and absolute number (graph) of OT-I cells from positive control mice (intact cross-priming and cross-decoration), cross-decoration only mice (deficient cross-priming), and cross-priming only mice (deficient cross-decoration) on day 56.

(C) Representative flow plots and frequency (graph) of IFNγ⁺ OT-I cells from positive control mice, cross-decoration only mice, and cross-priming only mice on day 56.

(D) F1.OVA kidney allografts were transplanted into either H-2Kb^FL/FL R26^CreERT2– or H-2Kb^FL/FL R26^CreERT2+ B6 recipients followed by adoptive transfer of 1 × 10⁶ effector OT-I cells 2 days post-transplantation. Tamoxifen chow was introduced from days 28–56, then recipients were subsequently harvested. n = 5–6 mice per group.

(E) Representative flow plots (left) and absolute number (graph) of T_RM OT-I cells after tamoxifen treatment at 56 days post-transplantation.

(F) Frequency of IFNγ⁺ OT-I cells after restimulation with F1.OVA donor splenocytes.

P values were determined by (B, C) one-way ANOVA with Tukey’s correction, and (E, F) two-tailed unpaired t test.