Gasdermin E deficiency limits inflammation and lung damage during influenza virus infection

Severe influenza A virus (IAV) infections are associated with hyperinflammation and significant lung damage. Gasdermin E (GSDME) mediates pyroptosis, a lytic and inflammatory type of cell death. Cleavage of GSDME by caspase-3 releases the active N-terminal domain, which subsequently forms transmembrane pores, leading to cell lysis and death. In this study, we investigated a role for GSDME in severe influenza. Infection of human bronchial epithelial cells revealed that IAV induces GSDME cleavage and activation, with the magnitude and kinetics of GSDME activation differing between IAV strains. Caspase-3-mediated GSDME activation preceded and overwhelmed gasdermin D (GSDMD) activation. siRNA silencing in vitro confirmed both gasdermins are active in human bronchial epithelial cells and cooperate to drive IAV responses. IAV infection of mice promoted GSDME cleavage in E-cadherin⁺ epithelial cells in vivo at day 3. Mice deficient in GSDME (Gsdme^-/-) showed improved survival and greater influenza disease resistance compared to their wildtype littermate controls. Gsdme^-/- mice exhibited reduced neutrophil infiltration and levels of cytokines IL-6 and IL-1β in the airways and IL-6, TNF, and IFNγ in the serum. This was accompanied by reduced viral loads, lung pathology, and epithelial cell death. Together, these findings demonstrate a pivotal role for GSDME in severe influenza pathogenesis.