Activation of meningeal ILC2s after SCI. (A) ILC2 IL-13 expression assessed by YFP mean fluorescence intensity (MFI) in YET-cre 13 mice in spinal cord (SC) meninges (i; P = 0.890) and brain meninges (ii; P = 0.007; n = 9, representative of three pooled experiments; Student’s t test). (B) Flow cytometry analysis of IL-13 expression in ILC2s at 1DPI in spinal cord meninges (i; P > 0.999) and brain meninges (ii; P < 0.001; n = 3, representative of two experiments; Student’s t test). (C) Flow cytometry analysis of IL-5 expression in ILC2s at 1DPI in spinal cord meninges (i; P = 0.624) and brain meninges (ii; P = 0.027; n = 3, representative of two experiments; Student’s t test). (D) WT and IL-33^−/− animals were injured, and meningeal ILC2s were analyzed for IL-13 expression 1DPI in spinal cord meninges (i; P = 0.358) and brain meninges (ii; P = 0.031; n = 4; Student’s t test). (E) WT and IL-33^−/− animals were injured, and meningeal ILC2s were analyzed for IL-5 expression 1DPI in spinal cord meninges (i; P = 0.753) and brain meninges (ii; P = 0.003; n = 4; Student’s t test). (F–H) Uninjured and 1DPI brain meningeal ILC2 transcriptomes were analyzed by RNAseq. (F) Volcano plot of injured versus uninjured ILC2 gene expression. 305 genes were significantly altered between groups (n = 3, each sample five pooled mice; adjusted p-value <0.050). (G and H) Gene sets enriched among differentially expressed genes in injured versus meningeal ILC2s. Histogram (G) and heat maps (H) of select gene sets and their component genes (n = 3, each sample five pooled mice; adjusted p-value <0.050). Error bars represent mean ± SEM; *, P ≤ 0.05; **, P ≤ 0.01.