Fig. 1

Treg expansion limits DR neurodegeneration. A-B, Hematoxylin and eosin analysis of retinal thickness. Representative images showing hematoxylin and eosin staining of db/+, db/db non-injected and db/db injected with either IL-2/mAb IL or its control (A). Quantification of the total retinal layer thickness as well as the thickness of the different cell layers (B). Scale bar is 50 μm. n = 5–8 mice. C-E, Immunostaining and quantitative analysis of photoreceptors. Representative images showing photoreceptors in the ONL (C) (Cones, CA⁺) in diabetic db/db animals non-injected, injected with the isotype, db/db animals receiving a Treg expansion and non-diabetic db/+ (scale bar = 25 μm). Quantitative analysis of the number of rows of DAPI⁺ nuclei in the ONL (D). Quantification of the number of cone photoreceptor cells (E) (CA⁺ cells) n = 4–5 animals. F-H, Immunostaining and analysis of rod bipolar cells and synaptic vesicles. Representative image of PKC-α (F) (upper panel, grey. Lower panel, green) and synaptophysin (red, lower panels). Stars indicate abnormal location of some PKC-α⁺ cell soma lower within the INL. Arrowheads indicate abnormal rod bipolar dendrite and synaptic vesicles sprouts into the ONL (scale bar = 25 μm). Quantitative analysis of the number of PKC-α⁺ somas close to OPL (G) (n = 4–6 mice) and (H), percentage of PKC- α⁺ somas found in a lower location out of the total of PKC-α⁺ cells (n = 4–6 animals). Data expressed as mean ± s.e.m. 1-way ANOVA followed by Tukey’s multiple comparisons test. * P < 0,05; **P < 0,01; *** P < 0,005; ****P < 0,001