Project description:Group 3 innate lymphoid cells (ILC3) are innate immune effectors that contribute to host defense. Whether ILC3 functions are stably modified following pathogen encounter is unknown. Here we assess the impact of a time-restricted enterobacterial challenge to long-term ILC3 activation. We found that intestinal ILC3 persist for months in an activated state following exposure to Citrobacter rodentium. Upon rechallenge, these “trained” ILC3 proliferate, display enhanced interleukin (IL)-22 responses, and have a superior cell-intrinsic capacity to control infection compared to naïve ILC3. Metabolic changes occur in C. rodentium-exposed ILC3 but only trained ILC3 have enhanced proliferative capacity that contributes to elevated IL-22 production. Accordingly, a limited encounter with a pathogen can promote durable phenotypic and functional changes in intestinal ILC3 that contribute to long-term mucosal defense.
Project description:Investigation of possible inhibitory effect of caffeine on catalase for dopamine conversion into salsolinol. Analyzed with 5 cm C18 column and a 6.5 minutes gradient elution.
Project description:Iron metabolism is pivotal for cell fitness in the mammalian host. However, its role in group 3 innate lymphoid cells (ILC3s) is unknown. Here we show that transferrin receptor CD71-mediated iron metabolism cell-intrinsically controls ILC3 maintenance, cytokine production and host protection against Citrobacter rodentium infection, and metabolically affects mitochondrial respiration by switching of oxidative phosphorylation toward glycolysis. Iron deprivation or Tfrc deficiency reduces the expression and/or activity of the aryl hydrocarbon receptor (Ahr), a ligand-dependent transcription factor and a key ILC3 regulator. Furthermore, consistent with its role in generation of Ahr ligand, microbiome exerts a negative impact on CD71 expression in an Ahr-dependent manner. Genetic ablation or activation of Ahr in ILC3s leads to CD71 upregulation or downregulation, respectively, suggesting an active suppression of CD71 by Ahr. Iron overload partially restores defective ILC3 compartment in the small intestine of Ahr-deficient mice, representing compensatory action of CD71 upregulation during Ahr deficiency. Mechanistically, Ahr directly binds to the promoter region of the Tfrc locus to inhibit Tfrc transcription. These data collectively demonstrate an under-appreciated role of the Ahr-CD71-iron axis in regulation of ILC3 maintenance and function.
Project description:Small intestinal group 3 innate lymphoid cells (ILC3) from ILC3-conditional BMAL1 knock out mice or littermate control mice were sort-purified for transcriptional analysis