Fig. 3: IL-12 and IL-23 receptor transcript expression and IL-12 protein levels in mouse and/or human postmortem brain tissue.

a, Il12rb1, coding for IL-12 receptor subunit β1, is equally expressed across all three mouse genotypes (as indicated) and occurs most pronouncedly in oligodendrocytes. Violin plot showing captured Il12rb1 transcripts across cell types. b, Il12rb2, coding for IL-12 receptor subunit β2, is strongly expressed in neurons and, to a lesser extent, in microglia, oligodendrocytes, OPCs and astrocytes. Violin plot showing captured Il12rb2 transcripts across cell types. c, Il23r transcripts were only barely expressed in the aged mouse hippocampus. Violin plot showing captured Il23r transcripts across cell types. d, smFISH on brain tissue of APPPS1 mice revealed Il12rb1 mRNA⁺ puncta (pink) in oligodendrocytes (marked by expression of Sox10 mRNAs (blue)); microglia expressing Tmem119 and Sall1 are marked by yellow puncta; DAPI shown in gray depicts cell nuclei. e, Il12rb2 mRNA⁺ puncta (pink) in neurons (marked by Map2 and NeuN mRNAs (yellow)); astrocytes expressing Aldh1l1, Gfap and Glast are marked in blue; DAPI shown in gray depicts cell nuclei. Signals specific to Il23r mRNA were not detectable. Scale bar, 25 μm. f, Human postmortem hippocampal brain tissue from individuals without dementia (n = 4) and from patients with AD (n = 3). qPCR results showing IL12RB2 and IL23R gene expression in bulk human hippocampal tissue, ****P = 1.678 × 10⁻⁹, t = 16.14, df = 12. Statistical analysis using two-tailed unpaired Student’s t-test. g–i, IL-12p70 protein as measured by ELISA in soluble tissue fraction of frontal cortex from age-matched non-AD controls (n = 14) and from patients with AD (n = 44). Statistical analysis using two-sided Mann–Whitney test for age-matched healthy controls (median = 0.5395 ± s.e.m.) and for patients with AD (median = 0.7946 ± s.e.m.), *P = 0.0316; Braak II–III: P = 0.8411, Braak V–VI: *P = 0.0117. df, degrees of freedom; NS, not significant.