Glaesserella parasuis serotype 5 disrupts the swine respiratory epithelial barrier via NBR1-mediated selective autophagic degradation of Claudin-1

  • Vet Microbiol. 2026 Jun:317:111030. doi: 10.1016/j.vetmic.2026.111030.
Qing Wang  1 ,  Chunli Song  2 ,  Chenyang Song  3 ,  Kuiru Fang  4 ,  Yingying Yuan  5 ,  Jiawen Wang  6 ,  Hongjie Fan  7
Affiliations
  • 1. Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Veterinary Medicine, Anhui Agricultural University, Hefei 230036, China. Electronic address: [email protected].
  • 2. Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Veterinary Medicine, Anhui Agricultural University, Hefei 230036, China. Electronic address: [email protected].
  • 3. Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Veterinary Medicine, Anhui Agricultural University, Hefei 230036, China. Electronic address: [email protected].
  • 4. Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Veterinary Medicine, Anhui Agricultural University, Hefei 230036, China. Electronic address: [email protected].
  • 5. Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Veterinary Medicine, Anhui Agricultural University, Hefei 230036, China. Electronic address: [email protected].
  • 6. Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Veterinary Medicine, Anhui Agricultural University, Hefei 230036, China. Electronic address: [email protected].
  • 7. MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China. Electronic address: [email protected].
PMID: 42000398 DOI: 10.1016/j.vetmic.2026.111030
Abstract

Glaesserella parasuis (G. parasuis) colonizes the upper respiratory tract of pigs and can cause systemic Infection through disruption of the epithelial barrier of the respiratory tract, resulting in substantial economic losses to the swine industry worldwide. A previous study revealed that Infection with the G. parasuis serotype 5 strain HPS5-SQ breaks through the swine respiratory epithelial barrier by inducing autophagic degradation of the tight junction protein Claudin-1. However, the underlying mechanism remains incompletely understood. In this study, co-immunoprecipitation (Co-IP) results revealed that Claudin-1 interacted with the selective Autophagy receptor NBR1 during HPS5-SQ Infection and that HPS5-SQ promoted the interaction between NBR1 and Claudin-1. Moreover, colocalization of Claudin-1, NBR1 and the autophagic marker protein LC3 was observed in HPS5-SQ-infected cells. These results suggested that NBR1 is involved in the degradation of Claudin-1 in HPS5-SQ-infected swine tracheal epithelial cells (STECs). In addition, knockout of NBR1 suppressed the reduction in Claudin-1 expression in HPS5-SQ-infected STECs, significantly restored the integrity of Claudin-1 and inhibited the increase in swine respiratory epithelial barrier permeability, resulting in decreased HPS5-SQ translocation. In general, the above results indicated that autophagic degradation of Claudin-1 induced by G.parasuis serotype 5 was dependent on the NBR1 receptor. Consequently, the epithelial barrier was disrupted. This study further revealed the mechanism by which G. parasuis serotype 5 breaks through the swine respiratory barrier, which is conducive to clarifying the pathogenic mechanism of G. parasuis Infection.

Keywords
Autophagy receptor NBR1; Glaesserella parasuis serotype 5 (GPS5); Swine respiratory epithelial barrier; Tight junction protein Claudin-1.
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