Study Identifies Immune Dysfunction in Adipose Tissue Linking Obesity to Severe Asthma
A new study using single-cell RNA sequencing found distinct immune cell changes in the fat tissue of adults with obesity-associated asthma compared to obese adults without asthma. Researchers identified shifts in macrophage populations, altered metabolic activity, and a signature of immune cell dysfunction marked by both activation and exhaustion. The findings suggest adipose tissue itself may be a therapeutic target for addressing the heightened asthma risk seen in people with obesity.
Researchers conducted single-cell RNA sequencing of the immune-rich stromovascular fraction of subcutaneous adipose tissue in well-characterized adults with obesity-associated asthma, matched against obese adults without asthma. Those with asthma showed increased abundance of perivascular macrophages and lymphoid-associated macrophages (LAMs), alongside reduced classical monocytes and naive CD4+ and CD8+ T cells. Pseudo-bulk differential expression analysis revealed upregulation of cellular metabolism — particularly oxidative phosphorylation — and downregulation of immune homeostatic pathways across multiple immune cell types. A notable finding was the induction of metallothionein gene expression in effector cells, a signature associated with simultaneous immune activation and exhaustion, suggesting a dysfunctional immune state. Gene co-expression modules linked to asthma diagnosis, lung function, and type 2 inflammatory biomarkers were enriched in these effector cell populations. Collectively, the data point to adipose tissue as an active site of immune dysregulation that may mechanistically contribute to asthma severity and therapeutic resistance in people with obesity.
What's missing
The study is a preprint posted to bioRxiv and has not yet undergone peer review. Key limitations include the cross-sectional design, which prevents causal inference, and the focus on subcutaneous adipose tissue only — visceral fat, which may have distinct immune profiles, was not examined. It also remains unclear whether the observed adipose immune changes precede asthma development or arise as a consequence of it.
What different sources said
- bioRxivCenter
Adipose tissue as a site of immune activation and dysfunction in individuals with obesity and asthma
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