Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1075J MRB IV, Nashville, TN 37232, USA; Willem-Alexander Children's Hospital, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
Cell Rep. 2023 Feb 28;42(2):112128. doi: 10.1016/j.celrep.2023.112128. Epub 2023 Feb 17.
The cytokine interleukin-23 (IL-23) is involved in the pathogenesis of inflammatory and autoimmune conditions including inflammatory bowel disease (IBD). IL23R is enriched in intestinal Tregs, yet whether IL-23 modulates intestinal Tregs remains unknown. Here, investigating IL-23R signaling in Tregs specifically, we show that colonic Tregs highly express Il23r compared with Tregs from other compartments and their frequency is reduced upon IL-23 administration and impairs Treg suppressive function. Similarly, colonic Treg frequency is increased in mice lacking Il23r specifically in Tregs and exhibits a competitive advantage over IL-23R-sufficient Tregs during inflammation. Finally, IL-23 antagonizes liver X receptor pathway, cellular cholesterol transporter Abca1, and increases Treg apoptosis. Our results show that IL-23R signaling regulates intestinal Tregs by increasing cell turnover, antagonizing suppression, and decreasing cholesterol efflux. These results suggest that IL-23 negatively regulates Tregs in the intestine with potential implications for promoting chronic inflammation in patients with IBD.
细胞因子白细胞介素 23(IL-23)参与炎症和自身免疫性疾病的发病机制,包括炎症性肠病(IBD)。IL23R 在肠道 Tregs 中富集,但 IL-23 是否调节肠道 Tregs 尚不清楚。在这里,我们专门研究了 Tregs 中的 IL-23R 信号,结果表明与来自其他隔室的 Tregs 相比,结肠 Tregs 高度表达 Il23r,并且在 IL-23 给药后其频率降低,并损害 Treg 抑制功能。同样,在缺乏 Il23r 的小鼠中,结肠 Treg 的频率增加,特别是在 Tregs 中,并且在炎症期间相对于 IL-23R 充分的 Tregs 具有竞争优势。最后,IL-23 拮抗肝 X 受体途径、细胞胆固醇转运蛋白 Abca1,并增加 Treg 凋亡。我们的研究结果表明,IL-23R 信号通过增加细胞周转、拮抗抑制和减少胆固醇外排来调节肠道 Tregs。这些结果表明,IL-23 在肠道中负调节 Tregs,这可能对促进 IBD 患者的慢性炎症具有重要意义。