IL1RL2 in immunity and intestinal homeostasis-Insights from patients with VEO-IBD

Atac, Leyla (2024): IL1RL2 in immunity and intestinal homeostasis-Insights from patients with VEO-IBD. Dissertation, LMU München: Medizinische Fakultät

Abstract

Very early onset inflammatory bowel disease (VEO-IBD) is distinguished by intense, early-onset inflammation in the gastrointestinal tract and is often connected to genetic mutations. VEO-IBD patients usually exhibit intense disease indications that are unresponsive to treatments. Several signatures, including IL10R, RIPK1, MD2, and CASP8 deficiencies, have been identified in our laboratory as prominent monogenic causes of IBD. Nevertheless, the majority of VEO-IBD patients remain without a genetic diagnosis, highlighting the essential need to comprehend the pathophysiology for effective clinical management. Our laboratory has utilized whole exome sequencing to examine one of the largest international cohorts of VEO-IBD, with the objective of identifying previously unexplored genetic markers. This genetical screen revealed compound heterozygous missense mutations (c.[952A>G];[965A>C]) and splice region mutation (c.1298-4C>T) in IL1RL2 (Interleukin 1 receptor-like 2) as a novel risk factor for VEO-IBD. This assessment purposed to enlighten the molecular mechanisms of IL1RL2 deficiency in macrophages and epithelial cells. The study utilized various advanced techniques, including CRISPR/Cas9-mediated genetic engineering, induced pluripotent stem cell (iPSC) differentiation towards macrophages and colonic organoids, and various immunological assays to investigate the impact of IL1RL2 mutations. Western blot analysis demonstrated reduced activation of the NFĸB and MAPK signaling pathways in patient-derived macrophages. Functional assays showed that the c.[952A>G];[965A>C] deficiency in IL1RL2 results in decreased expression of CD14, CD163, and CD273, indicating impaired macrophage polarization. Additionally, HCT116 cells expressing the c.952A>G or c.965A>C variants exhibited reduced NFĸB and MAPK activation, impaired wound healing, altered CCL20 expression, and increased cell death. iPSC-derived colonic organoids expressing c.[952A>G];[965A>C] or c.1298-4C>T exhibited impaired wound healing, altered IL1RL2 and CCL20 expression. This comprehensive study provides new insights into the molecular mechanisms underlying VEO-IBD and underscores the critical role of IL1RL2 in gut immunity. The findings suggest potential therapeutic targets for treating IBD through modulation of IL1RL2 signaling.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: IL1RL2, IL36, VEO-IBD, intestinal organoids, iPSC, wound healing
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften ; 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Fakultäten: Medizinische Fakultät
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 2. Dezember 2024
• 1. Bericht­erstatter:in: Klein, Christoph