Cd11c-Cre; β2m ^fl/fl mice selectively lack MHC-I on cDC1 and cDC2. (A–G) Splenocytes from WT, MHC-I TKO (Kb^−/− Db^−/− β2m^−/−), β2m^fl/fl, and Cd11c-Cre⁺; β2m^fl/fl mice were analyzed for surface expression of H-2K^b (A–F) or of H2-K^d (G). Shown are histograms and frequency of K^b+ cells for B cells (A), pDCs (B), macrophage/moDCs (C), total cDCs (D), cDC1s (E), and cDC2s (F). Data represent mean of pooled biologically independent samples (n = 2–3 for each genotype). Unpaired t test. (H) In vivo proliferation of OT-I and OT-II in WT or MHC-I TKO mice 3 days after intravenous immunization with the indicated dose of sOVA or OVA-IC. Data shown are from one representative experiment of two independent experiments with similar results. Ordinary two-way ANOVA. (I) In vivo OT-I proliferation in WT, Δ32, and Δ1+2+3 mice in response to low dose OVA-IC (0.3 μg per mouse.) Data are represented as mean values ± SD of pooled biologically independent samples from two independent experiments. Two-way ANOVA with Sidak’s multiple comparisons test. ns = not significant; *P < 0.05; **P < 0.01.