Cadherin-11 serves as a novel receptor for Fusobacterium nucleatum adhesin FadA to exacerbate pulmonary inflammation

Fusobacterium nucleatum, a periodontal pathogen, has been increasingly implicated in pulmonary diseases including chronic obstructive pulmonary disease (COPD). This study demonstrates that F. nucleatum adheres to and invades pulmonary epithelial cells in a dose-dependent manner, primarily mediated by its adhesin FadA. We identify cadherin-11 (CDH11), which is upregulated in COPD lungs and in pulmonary epithelial cells treated with F. nucleatum or FadAc protein, as the key host receptor for FadA. This FadA-CDH11 interaction not only mediates bacterial adhesion and invasion, but also activates the MAPK13/JUN pathway, leading to significant upregulation of pro-inflammatory cytokines including CSF3, TNF-α, CCL20, and TGF-β. Genetic knockdown of CDH11 abolishes MAPK13/JUN activation and cytokine induction but does not affect FadA-mediated p53 suppression, indicating a separate pathway for this oncogenic event. Our findings establish the FadA-CDH11-MAPK13/JUN axis as a central mechanism driving F. nucleatum-exacerbated pulmonary inflammation and tissue damage, highlighting its potential as a therapeutic target for mitigating COPD progression.