Fig. 7

Cytokine-primed NSCs hinder LNC proliferation via a mechanism that is partly dependent on secreted arginase I. a Cytosolic arginase I (green) expression in Nestin (white) immunoreactive NSCs is increased upon priming with Th1 and Th2 cytokines (arrowheads). Arginase II (green) co-localizes mostly with red mitochondria (arrows), and it is reduced by priming with Th1 cytokines only. Mitochondria are in red, while nuclei are counterstained with DAPI (blue). Data are expressed as mean intensity (±SD) over total DAPI and have been collected out of n ≥ 3 independent experiments. *p ≤ 0.05 and **p ≤ 0.01 vs. basal NSCs. Scale bars 40 μm. b After EAE (25 and 50 days post immunization—dpi), arginase I expression is increased in Nestin⁺ SVZ-resident NSCs (red), compared to healthy controls (left panels). On the contrary, arginase II expression by Nestin⁺ SVZ-resident NSCs (red) is reduced in EAE mice compared to healthy controls (right panels). CD45-positive leukocytes are showed in white; nuclei are counterstained with DAPI (blue). Scale bars 50 μm. c Arginase I and arginase II protein expression in NSC supernatants detected by western blotting. Western blot analyses were performed starting from the same protein quantity (100 μg of total protein). This panel is representative of n ≥ 3 independent experiments. d Representative dot plots of EdU⁺CD44^high CD4⁺ T cells. e Relative fraction of proliferating EdU⁺ cells within CD44^highCD4⁺ viable T cells. Data are expressed as mean EdU fold suppression (±SD) calculated dividing the percent of EdU⁺ cells in experimental samples over controls from n ≥ 3 independent experiments. Unpaired two-tailed t-test for comparisons between groups were applied; **p ≤ 0.01 and ***p ≤ 0.001 vs. LNC; °p ≤ 0.05 and °°p ≤ 0.01 vs. NSC/LNC