Presence of tertiary lymphoid structures in Aire−/− retinas. (A–D) Immunostaining of cross-sections of WT vs. Aire−/− retinas. (A) CD8 (green), CD19 (red), CD4 (magenta), and nuclei (DAPI; blue). (B) BCL6 (green), CD19 (red), CD4 (magenta), and nuclei (DAPI; blue). BCL6+CD4+ cells are indicated by arrows. (C) PNAd (green), CD19 (red), CD4 (magenta), and nuclei (DAPI; blue). A PNAd+ vessel resembling an HEV is indicated by the arrows. (D) MHC class II (I-A and I-E; green), CCR7 (red), CD4 (magenta), and nuclei (DAPI; blue). (E) CD80 (green), pZAP70 (red), CD4 (magenta), and nuclei (DAPI; blue). (F) SDC1 (green), CD19 (red), CD4 (magenta), and nuclei (DAPI; blue). CD19− SDC1+ plasma cells are indicated by arrows; a CD19+ SDC1+ plasmablast is indicated by the arrowheads. (Scale bars in A–F, 50 μm.)