Nat Commun. 2021 May 5;12(1):2538. doi: 10.1038/s41467-021-22764-2.

PPARɣ drives IL-33-dependent ILC2 pro-tumoral functions

Giuseppe Ercolano ^1 2, Alejandra Gomez-Cadena ^1 2, Nina Dumauthioz ³, Giulia Vanoni ³, Mario Kreutzfeldt ⁴, Tania Wyss ³, Liliane Michalik ⁵, Romain Loyon ^6 7, Angela Ianaro ⁸, Ping-Chih Ho ³, Christophe Borg ^6 7, Manfred Kopf ⁹, Doron Merkler ⁴, Philippe Krebs ¹⁰, Pedro Romero ³, Sara Trabanelli ^1 2, Camilla Jandus ^11 12Affiliations expand

• PMID: 33953160
• DOI: 10.1038/s41467-021-22764-2

Free article

Abstract

Group 2 innate lymphoid cells (ILC2s) play a critical role in protection against helminths and in diverse inflammatory diseases by responding to soluble factors such as the alarmin IL-33, that is often overexpressed in cancer. Nonetheless, regulatory factors that dictate ILC2 functions remain poorly studied. Here, we show that peroxisome proliferator-activated receptor gamma (PPARγ) is selectively expressed in ILC2s in humans and in mice, acting as a central functional regulator. Pharmacologic inhibition or genetic deletion of PPARγ in ILC2s significantly impair IL-33-induced Type-2 cytokine production and mitochondrial fitness. Further, PPARγ blockade in ILC2s disrupts their pro-tumoral effect induced by IL-33-secreting cancer cells. Lastly, genetic ablation of PPARγ in ILC2s significantly suppresses tumor growth in vivo. Our findings highlight a crucial role for PPARγ in supporting the IL-33 dependent pro-tumorigenic role of ILC2s and suggest that PPARγ can be considered as a druggable pathway in ILC2s to inhibit their effector functions. Hence, PPARγ targeting might be exploited in cancer immunotherapy and in other ILC2-driven mediated disorders, such as asthma and allergy.