Fig. 3.

Primary nodules are the first histopathological manifestation in RE and precede T-cell infiltration. a PNs are small microglia clusters devoid of T cells, which form around neurons (arrow). b In later histopathological stages, T cells infiltrate microglia nodules (arrowhead), often around neurons (arrow). c Quantification of PNs in controls (n = 7) and stage 0 cases (n = 5). d Densitometric measurements for IL-18 in microglia of controls (n = 7) and microglia-forming PNs in stage 0 (n = 5). e Densitometric measurements for caspase-1 in microglia of controls (n = 7) and microglia-forming PNs in stage 0 (n = 5). (Two-tailed Mann–Whitney test), representative pictures of caspase-1, weakly expressed in f controls, increased in g PN and further in h SN. IL-18 is weakly present in i controls, and increased abundancy in j PN and k SN. IL-1β is not found in l controls and m PN, but is highly abundant in n SN. The inflammasome activation is indicated by o cell quantification and p qPCR [controls (n = 7), stage 0 (n = 5), stage 1 (n = 7), stage 2 (n = 6)]. (Kruskal–Wallis Test with Dunn’s post hoc correction for multiple testing, p values indicated originate from the multiple comparisons, *p < 0.05, **p < 0.01). Data are represented as median with interquartile range. Scale bars in a, b represent 20 µm, in c, f, i 50 µm and in d, e, g, h, j, k 25 µm