Obesity alters pathology and treatment response in inflammatory disease.
Level 5 - mechanism / opinion, no new human data
Preclinical animal model and molecular mechanistic study
PubMed 35355021 · doi:10.1038/s41586-022-04536-0
What was done
Researchers evaluated immune responses in lean versus obese mice across two models of atopic dermatitis. They assessed therapeutic response to anti-TH2 biologic therapies, conducted single-cell RNA sequencing and genome-wide binding analyses of TH2 cells, tested conditional T-cell knockout of PPARγ, and measured the impact of co-administering a small-molecule PPARγ agonist.
What was found
Obesity shifted atopic dermatitis from a classical TH2-predominant profile to a more severe condition with prominent TH17 inflammation. Targeted anti-TH2 biologics protected lean mice but exacerbated disease in obese mice. Obese mice exhibited decreased PPARγ activity in TH2 cells, and conditional ablation of PPARγ in T cells similarly induced non-TH2 inflammation. Administering a PPARγ agonist to obese mice suppressed TH17 pathology and restored responsiveness to anti-TH2 biologics. The abstract reports no numerical values or effect sizes.
Why it matters
This study shows that underlying metabolic disease can flip the clinical effect of targeted immunotherapies from therapeutic to harmful, highlighting the role of metabolic context in precision immunology.
Limits
Findings are derived entirely from mouse models and in vitro molecular assays; no human clinical data or patient outcomes are included in the abstract. Animal sample sizes, quantitative effect sizes, and statistical confidence intervals are not reported in the abstract.
Cited by
- supports In mouse experiments, obesity induced by a high-fat diet qualitatively altered the inflammatory skin response to an allergen and caused standard allergy-blocking antibody treatments to fail or worsen inflammation.