Biology subjects

Cahill, K. N.

Publications and source records attributed to Cahill, K. N..

3 recordsLinked to original sources

bioRxiv2026

Adipose tissue as a site of immune activation and dysfunction in individuals with obesity and asthma

Obesity increases local inflammatory responses in adipose tissue. Individuals with obesity have increased asthma incidence and severity and reduced responses to asthma therapeutics through unknown mechanisms. To identify mechanisms by which increased fat mass augments asthma pathogenesis, single cell RNA sequencing of the immune-rich stromovascular fraction of subcutaneous adipose tissue was conducted from well-characterized adults with obesity-associated asthma matched to adults without asthma. Individuals with asthma had increased abundance of perivascular macrophages and lymphoid-associated macrophages (LAMs) and reduced abundance of classical monocytes and CD4+ and CD8+ naive T cells. Pseudo-bulk differential expression (DE) identified upregulation of cellular metabolism, specifically oxidative phosphorylation, and decreased immune homeostatic pathways in asthma across immune cell subsets. Cell type specific DE analysis of effector cell subtypes identified significant induction of metallothionein gene expression in asthma, a signature of immune cell dysfunction characterized by both an activation and exhaustion phenotype. Gene co-expression analysis identified gene modules associated with asthma diagnosis, lung function, and biomarkers of type 2 inflammation were enriched in effector cells. These data identify adipose tissue dysfunction occurs in obesity-associated asthma and support adipose tissue as therapeutic target to address the enhanced asthma risk among those with obesity. Grant SupportNIH U01AI155299, P30DK020593, R01AI182159, K23HL159351, UL1RR024975-03, P30CA68485, P30EY08126, G20RR030956, 5UL1TR002243, KL2TR002245, P30AI110527, DK020593, American Heart Association 17SFRN33520017.

immunology↗

bioRxiv2025

Ovarian Hormones and Obesity Drive Th17-mediated Airway Inflammation through Estrogen Receptor Signaling

Obesity is a risk factor for increased prevalence and severity of asthma, particularly in females. As adults, females have increased prevalence of asthma compared to males. Yet, the mechanisms remain unclear on how sex hormones and obesity increase airway inflammation. We hypothesize that estrogen signaling through estrogen receptor-alpha (ER-) in T cells increased airway inflammation in the context of obesity. To test our hypothesis, we utilized a high fat (HFD) on female and male mice that underwent ovariectomy or gonadectomy or in Esr1fl/fl X Cd4Cre+ male and female mice. As controls, mice in similar groups were fed normal chow. After 8-12 weeks on diets, house dust mite (HDM) sensitization and challenge occurred in all mice. Lungs and BAL fluid were harvested 24 hours after the last challenge. Ovarian hormones and ER- signaling in T cells increased eosinophils, neutrophils, and Th17-mediated airway inflammation in the lungs of obese female mice. Additionally, using PBMCs from a well-characterized obese asthma cohort, we determined that obese women with asthma had increased Th17 cells compared to obese men with asthma. Our results show that ER- signaling in T cells increases Th17-mediated airway inflammation in obese mice and that Th17 cells circulate at higher frequencies in women with asthma compared to men with asthma. Further research into the interplay between hormonal signaling and immune responses in asthma is essential for developing personalized treatments. One Sentence SummaryEstrogen receptor-alpha signaling, in the context of obesity, increases allergen-induced Th17-mediated airway inflammation in female mice.

immunology↗

bioRxiv2023

Androgen Signaling Restricts Glutaminolysis to Drive Sex-Specific Th17 Metabolism

Females have increased prevalence of many Th17-mediated diseases. While androgen signaling decreases Th17-mediated inflammation, the mechanisms are not fully understood. Th17 cells rely on glutaminolysis; however, it remains unclear whether androgen receptor (AR) signaling in males modifies glutamine metabolism to suppress Th17-mediated inflammation. We show that Th17 cells from male humans and mice had decreased glutaminolysis compared to females, and AR signaling attenuated Th17 cell mitochondrial respiration and glutaminolysis. Using allergen-induced airway inflammation models, we determined females, but not males, had a critical reliance upon glutaminolysis for Th17-mediated airway inflammation, and AR signaling attenuated glutamine uptake by reducing expression of glutamine transporters. These findings were confirmed in circulating human Th17 cells with minimal reliance on glutamine uptake in male compared to female Th17 cells. We found that AR signaling attenuates glutaminolysis, demonstrating sex-specific metabolic regulation of Th17 cells with implications for design and implementation of Th17 or glutaminolysis targeted therapeutics. HighlightsO_LIHuman male CD4+ T cells have decreased expression of metabolic enzymes and decreased reliance on glutaminolysis compared to female CD4+ T cells. C_LIO_LIAndrogen signaling decreased mitochondrial metabolism in Th17 cells and decreased airway inflammation. C_LIO_LIAndrogen signaling decreased glutamine uptake and utilization in Th17 cells. C_LI

immunology↗