Figure 1. Recruitment of T cells in aged C57BL/6 mice and effects in the chorioretinal layer. A: Flow cytometry analysis. Representative dot plots of CD4 and CD8 expression in CD3⁺-gated cells from cell suspensions of pooled choroid/RPE complexes from two eyes of 18-month-old C57BL/6 mice. SSC-A: Side-scattered light–area; FSC-H: Forward-scattered light–height; APC: Allophycocyanin; PE: Phycoerythrin. B-C: Absolute quantification of CD4 and CD8+ T cells in pooled choroid/RPE layers from young or aged C57BL/6 mice (B). Absolute quantification of CD4 and CD8+ T cells in pooled inner retina from young or aged C57BL/6 mice (C; n = 4–6 pooled sample, analysis of variance (ANOVA) and Tukey test). D: CXCL9 and CXCL10 protein expression in eyes from young and aged mice (n = 8/group, Mann–Whitney test) 4 days after the onset of illumination. E-F: Representative photomicrograph of 3-month-old C57BL/6 retina (E). Representative photomicrograph of a retina taken at the same distance from the optic nerve of an 18-month-old C57BL/6 mouse (F). G: RPE thickness in µm² (-3,000 μm: inferior pole, +3,000 μm: superior pole, 0 μm: optic nerve) in young (n = 4) and old C57BL/6J mice (n = 10). Area under the curve (AUC) in young and old C57BL/6 mice (Student t test) in the whole retina and restricted to the central retina. H: Quantitative PCR of RPE65 mRNA of young and aged C57BL/6 mice (n = 5–6 per group, Student t test). I: Choroidal thickness in µm² (-3,000 μm: inferior pole, +3, 000 μm: superior pole, 0 μm: optic nerve) in young (n = 4) and old C57BL/6J mice (n = 10). AUC in young and old C57BL/6 mice (Student t test) in the whole retina and restricted to the central retina. ONL: Outer nuclear layer; ret; Retina; cho: Choroid, rpe; Retinal pigment epithelium. All scale bars represent 20 µm. All values are represented as mean ± standard error of the mean (SEM), *p≤0.05, **p≤0.01, ***p≤0.001.