Claudin 1 is involved in CAT and homeostatic DC1 maturation. (A) Representative flow cytometry plots show the acquisition of TdTOMATO by thymic DC subsets from Defa6^iCreR26^TdTOMATO mice. FMO controls are shown (R26^TdTOMATO). (B) Frequency of TdTOMATO⁺ cells and MFI of TdTOMATO expression within thymic DC subsets from Fig. 3 A (mean ± SEM, n = 7 mice from two independent experiments). (C) Frequency of CLAUDIN 1⁺ cells and MFI of CLAUDIN 1 expression within TdTOMATO⁺ and TdTOMATO⁻ DC1 subsets from thymi of Defa6^iCreR26^TdTOMATO mice (mean ± SEM, n = 9–14 mice from a minimum of three independent experiments). (D) Schematic of competitive BM chimera experiment assessing the role of Claudin 1 in CAT. (E) Representative flow cytometry plots show the frequency of TdTOMATO⁺ cells within Claudin 1–sufficient (Ly5.1 BM) and Claudin 1–deficient (XCR1^iCreCldn1^fl/fl BM) DC1 subsets from competitive BM chimeras in Fig. 3 D. FMO controls are shown (R26^TdTOMATO mouse). (F) Frequency of TdTOMATO⁺ cells within Claudin 1–sufficient and Claudin 1–deficient DC1 subsets from Fig. 3 E (mean ± SEM, n = 10 mice from three independent experiments). (G) Violin plots from scRNAseq analysis (Fig. 1) show the expression of cholesterol efflux–associated genes within CAT-experienced (orange) and CAT-inexperienced (gray) DC1 (left panel) and DC1 lineage subsets (right panel). (H) Frequency of individual DC1 subsets within thymic DCs from Claudin 1–sufficient (solid circle) and Claudin 1–deficient (empty circle) BM from Fig. 3 D (mean ± SEM, n = 10 mice from three independent experiments). Statistical analysis in C, F, and H was performed using paired, two-tailed Student’s t test, *P ≤ 0.05, ***P ≤ 0.001, ****P < 0.0001, ns = not significant. All mice were bred on the B6 background. Littermates were used as controls.