In vivo cross-priming with IC requires cDC1 or cDC2. (A) Sorting strategy for cDC1, cDC2, monocytes, and macrophage/moDCs. (B) In vitro proliferation of OT-I cultured with the indicated APC and either 1 μg/ml of sOVA or OVA-IC. Data are represented as mean values ± SD combined from three independent experiments. Multiple t tests. *P < 0.05; **P < 0.01. (C) In vivo OT-I proliferation in β2m^fl/fl, CD11c-Cre⁺; β2m^fl/fl, or MHC-I TKO (Kb^−/−; Db^−/−; and β2m^−/−) mice 3 days after intravenous immunization with 1 μg OVA-IC. (D) Frequencies of OT-I proliferation from mice in C. Data are represented as mean values ± SD of pooled biologically independent samples from two independent experiments (n = 6 for β2m^fl/fl and CD11c-Cre⁺; β2m^fl/fl; n = 4 for MHC-I TKO mice). ns = not significant; *P < 0.05; **P < 0.01; ****P < 0.0001. (E) In vivo OT-I proliferation in WT, Δ32, and Δ32 × Δ1+2+3 mice on day 3 after intravenous immunization with 1 μg OVA-IC. Data represent mean ± SEM of pooled biologically independent samples from two independent experiments (n = 7 for WT and Irf8 Δ 32 mice; n = 6 for Δ32 × Δ1+2+3 mice). (D and F) Brown–Forsythe and Welch ANOVA with Dunnett’s T3 multiple comparisons test. ns = not significant; **P < 0.01.