Protective Activity of Programmed Cell Death Protein 1 Blockade and Synergy With Caspofungin in a Murine Invasive Pulmonary Aspergillosis Model

Pharmacological immune checkpoint blockade has revolutionized oncological therapies, and its remarkable success has sparked interest in expanding checkpoint inhibitor therapy in infectious diseases. Herein, we evaluated the efficacy of programmed cell death protein 1 (PD-1) blockade in a murine invasive pulmonary aspergillosis model. We found that, compared with isotype-treated infected control mice, anti–PD-1–treated mice had improved survival, reduced fungal burden, increased lung concentrations of proinflammatory cytokines and neutrophil-attracting chemokines, and enhanced pulmonary leukocyte accumulation. Furthermore, combined treatment with anti–PD-1 and caspofungin resulted in a significant survival benefit compared with caspofungin or anti–PD-1 therapy alone, indicating a synergistic effect between PD-1 inhibitors and immunomodulatory antifungal agents.