Gasdermin D restricts anti-tumor immunity during PD-L1 checkpoint blockade.

Tumor microenvironments (TMEs) require co-operation of innate and adaptive immune cells, which influence tumor progression and immunotherapy. Caspase-activated gasdermins facilitate tumor death and promote anti-tumor immunity. How pyroptosis in immune cells affects the TME remains unclear. TME expression of gasdermin D (GSDMD) is highly expressed in antigen-presenting cells (APCs) and correlates with immune checkpoint signatures. Through conditional deletion of GSDMD, we demonstrate that GSDMD in TME APCs restricts anti-tumor immunity during PD-L1 inhibition. Loss of GSDMD in APCs enhances interferon-stimulated genes (ISGs), thereby promoting CD8+ T cell activation in a cGAS-dependent manner. Moreover, pharmacological inhibition of GSDMD-mediated pyroptosis and PD-L1 improve anti-tumor immunity, highlighting the potential of combining GSDMD/PD-L1 inhibition for immunotherapy as a therapeutic strategy.