Elastin-derived peptides suppress CCL20 expression and block ILC2 recruitment during lung inflammation

Elastin degradation during chronic lung inflammation generates elastin peptides (EPs) with immunomodulatory properties. Because elastin is abundant in the lung, its breakdown in diseases such as chronic obstructive pulmonary disease (COPD) and asthma produces high EPs levels that may influence local immune responses. Here, we investigated the impact of EPs on group 2 innate lymphoid cells (ILC2) using mouse models of EP-induced emphysema and house dust mite (HDM)–induced asthma. EPs instillation reduced lung ILC2 numbers without affecting Th2 cells. In patients with COPD, we observed decreased CCL20 expression in lung immune cells and an inverse correlation between serum CCL20 levels and clinical indicators of elevated EPs burden. We also showed that EPs instillation during HDM-induced lung inflammation directly decreased CCL20 expression. These findings identify EPs as regulators of ILC2 trafficking through CCL20 downregulation, revealing a direct link between extracellular matrix (ECM) degradation and the chemokine networks orchestrating type 2 immunity.