Gut-derived memory γδ T17 cells exacerbate sepsis-induced acute lung injury in mice

Abstract

Sepsis is a critical global health concern linked to high mortality rates, often due to acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). While the gut-lung axis involvement in ALI is recognized, direct migration of gut immune cells to the lung remains unclear. Our study reveals sepsis-induced migration of γδ T17 cells from the small intestine to the lung, triggering an IL-17A-dominated inflammatory response in mice. Wnt signaling activation in alveolar macrophages drives CCL1 upregulation, facilitating γδ T17 cell migration. CD44 ⁺ Ly6C ^– IL-7R ^high CD8 ^low cells are the primary migratory subtype exacerbating ALI. Esketamine attenuates ALI by inhibiting pulmonary Wnt/β-catenin signaling-mediated migration. This work underscores the pivotal role of direct gut-to-lung memory γδ T17 cell migration in septic ALI and clarifies the importance of localized IL-17A elevation in the lung.

Abstract

Sepsis can result in acute lung injury which may involve cross interaction via the gut-lung axis. Here the authors show γδ T17 cell migration from the gut to the lung in a murine model of sepsis and link IL-17A-mediated lung inflammation regulation by Wnt/β-catenin signaling in alveolar macrophages via CCL1.