Fig. 5.

EV-associated IL33 induced MC activation. A Violin plots and UMAP depiction of Il1rl1 (Il33 receptor) expression in KO tumors. Expression of Il1rl1 was low on Treg cells and similar between KO and WT (Fig. S5D). Surface expression of Il1rl1 measured using flow cytometry was detectable on MC/9 cells but absent on WT and KO Pan02 cells (Fig. S5E). B RT-qPCR of Il1rl1 gene expression in tumor tissue normalized to Rpl32 (mean ± SEM, n = 7–9). C ELISA to detect mouse and human IL33 in EVs and EV purified soluble fractions (-sol) from WT and KO PDAC cells (mean ± SEM, n = 3). D Murine MCs pre-treated with EVs or crude supernatant (SN) from KO and WT Pan02 cells were analyzed for Ilrl1(IL33 receptor) expression. Cd117 expression was used as a control (mean ± SEM, n = 4–5). E Cytokine gene expression analysis of mouse and human MCs stimulated with KO- or WT-EVs isolated from Pan02 and PANC-1 cells, respectively. Data were normalized to Rpl32 (mean ± SEM, n = 4–6, 2 independent experiments). F Microbead assay to measure Il33 expression on WT-/KO-EVs from Pan02 cells (mean ± SEM, n = 6). Statistical significance: (A–F) unpaired Mann–Whitney U test t-test; *P < 0.05; **P < 0.01