CD177+ cells produce neutrophil extracellular traps that promote biliary atresia

J Hepatol. 2022 Nov;77(5):1299-1310. doi: 10.1016/j.jhep.2022.06.015. Epub 2022 Jul 5.


Background & aims: We have previously reported on the potential pathogenic role of neutrophils in biliary atresia (BA). Herein, we aimed to delineate the role of CD177+ neutrophils in the pathogenesis of BA.

Methods: Immune cells from the livers of mice with rhesus rotavirus-induced BA were analysed. Single-cell RNA-sequencing was performed to specifically analyse Gr-1+ (Ly6C/Ly6G+) cells in the liver. Gene expression profiles of CD177+ cells were analysed using the Smart-Seq RNA-sequencing method, and the pathogenesis of BA was examined in Cd177-/- mice. Neutrophil extracellular trap (NET) inhibitors were used to determine the role of CD177+ cell-derived NETs in BA-associated bile duct damage, and a pilot clinical study evaluated the potential effects of N-acetylcysteine on NET release in BA.

Results: Increased levels of Gr-1+ cells were observed in the livers of mice with rhesus rotavirus-induced BA. RNA-sequencing analysis revealed that CD177+ cells were the main population of Gr-1+ cells and expressed elevated levels of both interferon-stimulated and neutrophil degranulation genes. Cd177-/- BALB/c mice exhibited delayed disease onset and reduced morbidity and mortality. High numbers of mitochondria were detected in CD177+ cells derived from mice with BA; these cells were associated with increased levels of reactive oxygen species and increased NET formation, which induced the apoptosis of biliary epithelial cells in cocultures. In a pilot clinical study, the administration of N-acetylcysteine to patients with BA reduced CD177+ cell numbers and reactive oxygen species levels, indicating a potential beneficial effect.

Conclusions: Our data indicate that CD177+ cells play an important role in the initiation of BA pathogenesis via NET formation.

Clinical trial registration: The pilot study of N-acetylcysteine treatment in patients with BA was registered on the Chinese Clinical Trial Registry (ChiCTR2000040505).

Lay summary: Neutrophils (a type of innate immune cell, i.e. an immune cell that doesn't target a specific antigen) are thought to play a role in the development of biliary atresia (a rare but potentially lethal condition of the bile ducts that occurs in infants). Herein, we found that neutrophils expressing a particular protein (CD177) played an important role in bile duct damage by releasing a special structure (NET) that can trap and kill pathogens but that can also cause severe tissue damage. A pilot study in patients with biliary atresia showed that inhibiting NETs could have a beneficial effect.

Keywords: Apoptosis; Biliary atresia; CD177; Gr-1; Mitochondria; Neutrophil extracellular trap; ROS; biliary epithelial cell.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine
  • Animals
  • Biliary Atresia* / pathology
  • Disease Models, Animal
  • Extracellular Traps*
  • Interferons
  • Mice
  • Mice, Inbred BALB C
  • Pilot Projects
  • RNA
  • Reactive Oxygen Species
  • Rotavirus* / genetics


  • Reactive Oxygen Species
  • RNA
  • Interferons
  • Acetylcysteine