Intranasal nanoparticle targeting neutrophil ORAI1 mitigates pancreatitis- and sepsis-associated acute lung injury

Acute lung injury arising from acute pancreatitis or sepsis remains a major clinical challenge and lacks specific therapeutic strategies. Neutrophil activation and infiltration, tightly governed by intracellular Ca²⁺ signaling via ORAI1-based Ca²⁺ release-activated Ca²⁺ (CRAC) channels, play central roles in the pathogenesis of acute lung injury. Here, we engineered a neutrophil-targeted lipid nanoparticle (neutLNP) encapsulating the selective CRAC channel inhibitor CM4620 (Anti-Ly6G@CM4620-LNP) for intranasal delivery. The neutLNP efficiently suppressed neutrophil chemotaxis and reactive oxygen species production, and significantly attenuated lung injury in both pancreatitis- and sepsis-associated lung injury models. Compared with intranasally administered free CM4620, neutLNP produced greater reductions in selected histological and inflammatory endpoints. Pulmonary imaging and flow cytometry demonstrated distribution within the inflamed lung parenchyma and preferential association with pulmonary neutrophils, whereas pharmacokinetic analysis showed markedly lower plasma CM4620 exposure after intranasal than after intraperitoneal administration. Mechanistically, integrated transcriptomic and single-cell proteomic profiling of pulmonary neutrophils from neutrophil-specific Orai1-deficient mice identified CD166 as a downstream mediator of ORAI1 signaling. Further analyses showed that ORAI1 signaling transcriptionally promotes CD166 expression, at least in part through NFATc2. Together, these findings support intranasal neutLNP delivery as a locally directed strategy that enhances lung protection relative to intranasal free CM4620 while limiting systemic exposure compared with intraperitoneal delivery, and establish CD166 as a functionally important downstream mediator of ORAI1-dependent neutrophil adhesion in acute inflammatory lung injury.