Fig 2: (A) Prior to FNA, FMN constitutively produces IL-10. Microglia constitutively transcribe Il10 mRNA, but protein translation is unknown. (B) Astrocytic IL-10 production is axotomy-induced. (C) The appearance of CD4+ T cells in the FMNuc promotes upregulation of IL-10R expression on resident cells [1,9], which may provide trophic support to injured FMN. (D) CD4+ T cells must express the IL-10R to modulate microglial activation and confer neuroprotection [9].

Fig 3: Fluorescent in situ hybridization for Il10 and Cx3cr1 mRNA transcripts.

Fig 4: Transient conditional depletion of Foxp3+ Tregs activates the CP for leukocyte trafficking and mitigates AD pathology.(a) AD-Tg/Foxp3-DTR+ and non-DTR-expressing AD-Tg littermates (AD-Tg/Foxp3-DTR-; AD-Tg control) were treated with DTx for 4 consecutive days. mRNA levels of icam1, cxcl10 and ccl2 in the CP of 6-month-old AD-Tg/Foxp3-DTR+ mice, 1 day after last injection (n=6–8 per group; Student's t-test). (b) Representative images of the CP, immunostained for E-Cadherin (green), ICAM-1 (red) and Hoechst, in 6-month-old AD-Tg/Foxp3-DTR+ mice, 1 day after last DTx injection (Scale bar, 25 µm). (c) mRNA levels of icam1 and vcam1, in cultured CP cells, 24 h after addition of ex vivo differentiated Tregs, IFN-? or their combination, relative to untreated (UT) cells (n=3–4 per group; one-way ANOVA followed by Newman–Keuls post hoc test; NS, not significant). (d–f) Flow cytometry analysis of the brain of 6-month-old AD-Tg/Foxp3-DTR+ mice, 3 weeks following last DTx injection, showing increased numbers of CD11bhigh/CD45high mo-MF and CD4+ T cells (d), and increased CD4+Foxp3+ (e,f) Treg frequencies (n=4–7 per group; Student's t-test). (g) mRNA levels of foxp3 and il10 in the brain of 6-month-old AD-Tg/Foxp3-DTR+ mice, 3 weeks after last DTx injection (n=6–8 per group; Student's t-test). (h,i) Representative images of Aß (green) and CD3 (red) (h), or Foxp3 and IL-10 (in red) immunostaining (i) in 6-month-old AD-Tg/Foxp3-DTR+, 3 weeks following last DTx injection (scale bar, 10 µm). (j) mRNA levels of il-12p40 and tnf-a in the brain of 6-month-old AD-Tg/Foxp3-DTR+ mice, 3 weeks after last DTx injection (n=6–8 per group; Student's t-test). (k,l) Representative images (k) and analysis (l) of GFAP immunostaining in hippocampal sections of 6-month-old AD-Tg/Foxp3-DTR+ mice, 3 weeks following the last DTx injection (scale bar, 250 µm; n=3–5 per group; Student's t-test). (m,n) Representative images (m) and analysis (n), of 5-month-old AD-Tg/Foxp3-DTR+ mice brains, immunostained for Aß (in red) and Hoechst, 3 weeks after the last DTx injection (scale bar, 250 µm). Mean Aß area and plaque numbers in the dentate gyrus (DG) and the cortex fifth layer (n=5–6 per group; Student's t-test). (o–q) Morris water maze (MWM) of 6-month-old AD-Tg/Foxp3-DTR+, 3 weeks after last DTx injection. DTx-treated mice showed improved spatial learning/memory in the acquisition (o), probe (p) and reversal (q) phases, relative to AD-Tg controls (n=7–9 per group; two-way repeated measures ANOVA followed by Bonferroni post hoc test; *P<0.05 for overall acquisition, probe and reversal). In all panels, error bars represent mean±s.e.m.; *P<0.05; **P<0.01; ***P<0.001.