Modulating inflammation with interleukin 37 treatment ameliorates murine Autosomal Dominant Polycystic Kidney Disease.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a leading cause of kidney failure and is associated with substantial morbidity and mortality. Interstitial inflammation is attributed to the action of infiltrating macrophages and is a feature thought to aggravate disease progression. Here, we investigated the therapeutic potential of the anti-inflammatory IL37b cytokine as a treatment for ADPKD using genetic mouse models, demonstrating that transgenic expression of human IL37b reduced collecting duct cyst burden in both early and adult-onset ADPKD rodent models. Moreover, injection of recombinant human IL37b could also reduce cyst burden in early onset ADPKD mice, an observation not associated with increased macrophage number at early stages of cyst formation. Interestingly, transgenic IL37b expression also did not alter macrophage numbers in advanced disease. Whole kidney RNA-seq highlighted an IL37b-mediated upregulation of the interferon signaling pathway and single-cell RNA-seq established that these changes originate at least partly from kidney resident macrophages. We further found that blocking type I interferon signaling in mice expressing IL37b resulted in increased cyst number, confirming this as an important pathway by which IL37b exerts its beneficial effects. Thus, our studies show that IL37b promotes interferon signaling in kidney resident macrophages which suppresses cyst initiation, identifying this protein as a potential therapy for ADPKD.