Anti-PD-1 exacerbates bleomycin-induced lung injury in mice via Caspase-3/GSDME-mediated pyroptosis.

Immune checkpoint inhibitors (ICIs) have significant therapeutic effects but can also cause fatal lung injury. However, the lack of mouse animal models of ICI-related lung injury (ICI-LI) has limited the in-depth exploration of its pathogenesis. In clinical practice, underlying lung diseases increase the risk of lung injury. Thus, we used a mouse model of lung injury induced by bleomycin (BLM) and then administered anti-programmed cell death 1 (aPD-1) antibodies to induce ICI-LI. Compared with the BLM group, the aPD-1 + BLM group presented more significant weight loss, greater levels of lung inflammation and fibrosis, and decreased lung function. In this ICI-LI model, high levels of caspase-3/gasdermin E (GSDME) were detected in the lung tissue of mice, and the JNK inhibitor SP600125 mitigated lung damage by inhibiting GSDME-mediated pyroptosis. Consistent with the findings in the animal model, immunofluorescence and RNA sequencing of lung tissue from ICI-LI patients revealed upregulation of the expression of genes related to the GSDME-related pyroptosis pathway. Our results suggest that GSDME-mediated pyroptosis may be associated with the pathogenesis of ICI-LI, indicating that targeting GSDME could be a potential therapeutic strategy for treating ICI-LI.