Polyamines are increased in IL-23–activated ILC3s.
(A) Polyamine synthesis pathway. ODC catalyzes the rate-limiting step of the conversion of ornithine to putrescine in the polyamine synthesis pathway. Putrescine acts as a substrate for the synthesis of spermidine, which in turn acts a substrate for the synthesis of spermine. (B) MNK-3 cells were activated by IL-1β (n = 4), IL-23 (n = 4), or left untreated (NT) (n = 6) for 18 h. Cells were harvested and subjected to targeted metabolomics analysis by HPLC-MS. Each point represents one well, and bars indicate mean. Data presented are representative of two independent experiments. ***p < 0.001, ****p < 0.0001. Differences that were not significant (p > 0.05) are marked as “ns.”