Eosinophils are leukocytes with broad roles in tissue homeostasis and innate immunity. However, eosinophils also reside within healthy adipose tissue.
Adipose tissue-resident eosinophils play homeostatic roles and regulate the activation of beige adipocytes. Beige adipocytes residing within white adipose tissue burn fuels to generate heat, by a process called thermogenesis, and therefore could be harnessed to reduce obesity by burning rather than storing excess fuels. We recently uncovered gene regulatory mechanisms in mice that allow adipose tissue-resident eosinophils to secrete molecules important for beige fat activation and prevention of weight gain.
Given the potential of adipose tissue-resident eosinophils to drive weight loss, we sought to generate a better understanding of these cells. We performed bulk RNA-seq in mouse FACS-isolated adipose tissue-resident eosinophils and compared gene expression to blood eosinophils. We found a unique transcriptional landscape in adipose tissue-resident eosinophils that is distinct from blood eosinophils in circulation. Differential gene expression of surface receptors and chemokines suggests that adipose tissue-resident eosinophils functionally adapt to their tissue niche.
We are now working to dissect the transcription factor network that drives the unique gene expression profile of adipose tissue-resident eosinophils. We are also testing whether novel adipose tissue-resident eosinophil secreted proteins can induce beiging and may present novel targets for obesity and are extending our findings to human adipose tissue-resident eosinophils.