A host-pathogen metabolic synchrony that facilitates disease tolerance

Area of Science:

• Microbiology
• Immunology
• Metabolic Engineering

Background:

• Disease tolerance mechanisms are crucial for mitigating organ damage during persistent infections but remain poorly understood.
• Understanding host-pathogen metabolic interactions is key to developing novel therapeutic strategies.

Purpose of the Study:

• To elucidate the role of itaconate in mediating disease tolerance during Pseudomonas aeruginosa pneumonia.
• To investigate the molecular mechanisms by which itaconate influences host-pathogen interactions and bacterial adaptation.

Main Methods:

• Utilized a Pseudomonas aeruginosa pneumonia mouse model to study disease tolerance.
• Analyzed the impact of itaconate on bacterial TCA cycle enzymes and biofilm formation.
• Investigated host metabolic pathways, including glutamine assimilation and glutaminolysis.
• Examined clinical samples for bacterial compensatory mutations.

Main Results:

• Itaconate, a mitochondrial metabolite, is essential for disease tolerance in P. aeruginosa pneumonia.
• Itaconate modifies bacterial succinate metabolism, inducing bioenergetic stress and promoting less immunostimulatory biofilms.
• The itaconate-alginate interplay in biofilms limits host immunopathology by regulating pulmonary glutamine metabolism and inflammasome activity.
• Compensatory mutations in mucA allow P. aeruginosa to restore bioenergetics and evade disease tolerance.

Conclusions:

• Itaconate orchestrates a metabolic dialogue between host and pathogen to establish disease tolerance.
• Targeting the itaconate-mediated metabolic synchrony presents a potential therapeutic avenue for persistent bacterial infections.
• Bacterial adaptation through specific mutations can overcome host-imposed metabolic constraints, highlighting the dynamic nature of host-pathogen interactions.