Ferroptosis mediated by the IDO1/Kyn/AhR pathway triggers acute thymic involution in sepsis.
Summary
In pediatric sepsis, elevated Kyn/Trp ratios indicate IDO1 activation, which drives AhR signaling and thymocyte ferroptosis, resulting in acute thymic involution. Pharmacologic IDO1 inhibition restored thymic function and improved survival in septic mice, identifying a targetable immunometabolic pathway.
Key Findings
- Pediatric sepsis patients exhibited elevated Kyn/Trp ratios and higher Kyn levels; Kyn inversely correlated with thymus-to-thorax ratio.
- Inflammation-induced IDO1 increased Kyn, activated AhR, and triggered ferroptosis-related transcription in thymocytes during sepsis.
- IDO1 inhibition with 1-methyltryptophan restored thymic function and improved survival in septic mice.
Clinical Implications
Measuring Kyn/Trp or downstream signatures could stratify immune dysfunction in sepsis. IDO1 inhibitors or ferroptosis modulators merit translational evaluation to prevent thymic involution and improve host defense in selected patients.
Why It Matters
This study uncovers a mechanistic link between tryptophan catabolism, ferroptosis, and immunosuppression in sepsis, with interventional evidence in vivo. It suggests a plausible therapeutic strategy (IDO1/AhR/ferroptosis axis) to reverse immune dysfunction.
Limitations
- Human sample size and detailed cohort characteristics are not specified; human data are correlative.
- Preclinical mouse findings may not fully generalize to heterogeneous clinical sepsis.
Future Directions
Validate Kyn/AhR/ferroptosis signatures in larger human cohorts; assess safety and efficacy of IDO1 inhibitors or ferroptosis modulators in early-phase sepsis trials; explore combinatorial immunometabolic therapies.
Study Information
- Study Type
- Basic/Mechanistic study
- Research Domain
- Pathophysiology
- Evidence Level
- V - Preclinical mechanistic evidence with supportive human associative data
- Study Design
- OTHER