Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.

Streptococcus suis serotype 2 (SS2) is a major zoonotic pathogen resulting in manifestations as pneumonia and septic shock. The upper respiratory tract is typically thought to be the main colonization and entry site of SS2 in pigs, but the mechanism through which it penetrates the respiratory barrie...

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Main Authors: Yu Meng, Qing Wang, Zhe Ma, Weiyi Li, Kai Niu, Ting Zhu, Huixing Lin, Chengping Lu, Hongjie Fan
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-08-01
Series:PLoS Pathogens
Online Access:https://doi.org/10.1371/journal.ppat.1010765
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author Yu Meng
Qing Wang
Zhe Ma
Weiyi Li
Kai Niu
Ting Zhu
Huixing Lin
Chengping Lu
Hongjie Fan
author_facet Yu Meng
Qing Wang
Zhe Ma
Weiyi Li
Kai Niu
Ting Zhu
Huixing Lin
Chengping Lu
Hongjie Fan
author_sort Yu Meng
collection DOAJ
description Streptococcus suis serotype 2 (SS2) is a major zoonotic pathogen resulting in manifestations as pneumonia and septic shock. The upper respiratory tract is typically thought to be the main colonization and entry site of SS2 in pigs, but the mechanism through which it penetrates the respiratory barrier is still unclear. In this study, a mutant with low invasive potential to swine tracheal epithelial cells (STECs) was screened from the TnYLB-1 transposon insertion mutant library of SS2, and the interrupted gene was identified as autolysin (atl). Compared to wild-type (WT) SS2, Δatl mutant exhibited lower ability to penetrate the tracheal epithelial barrier in a mouse model. Purified Atl also enhanced SS2 translocation across STEC monolayers in Transwell inserts. Furthermore, Atl redistributed the tight junctions (TJs) in STECs through myosin light chain kinase (MLCK) signaling, which led to increased barrier permeability. Using mass spectrometry, co-immunoprecipitation (co-IP), pull-down, bacterial two-hybrid and saturation binding experiments, we showed that Atl binds directly to vimentin. CRISPR/Cas9-targeted deletion of vimentin in STECs (VIM KO STECs) abrogated the capacity of SS2 to translocate across the monolayers, SS2-induced phosphorylation of myosin II regulatory light chain (MLC) and MLCK transcription, indicating that vimentin is indispensable for MLCK activation. Consistently, vimentin null mice were protected from SS2 infection and exhibited reduced tracheal and lung injury. Thus, MLCK-mediated epithelial barrier opening caused by the Atl-vimentin interaction is found to be likely the key mechanism by which SS2 penetrates the tracheal epithelium.
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spelling doaj.art-73d82eb105374d778da03ffed7d44ae52022-12-22T03:20:27ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742022-08-01188e101076510.1371/journal.ppat.1010765Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.Yu MengQing WangZhe MaWeiyi LiKai NiuTing ZhuHuixing LinChengping LuHongjie FanStreptococcus suis serotype 2 (SS2) is a major zoonotic pathogen resulting in manifestations as pneumonia and septic shock. The upper respiratory tract is typically thought to be the main colonization and entry site of SS2 in pigs, but the mechanism through which it penetrates the respiratory barrier is still unclear. In this study, a mutant with low invasive potential to swine tracheal epithelial cells (STECs) was screened from the TnYLB-1 transposon insertion mutant library of SS2, and the interrupted gene was identified as autolysin (atl). Compared to wild-type (WT) SS2, Δatl mutant exhibited lower ability to penetrate the tracheal epithelial barrier in a mouse model. Purified Atl also enhanced SS2 translocation across STEC monolayers in Transwell inserts. Furthermore, Atl redistributed the tight junctions (TJs) in STECs through myosin light chain kinase (MLCK) signaling, which led to increased barrier permeability. Using mass spectrometry, co-immunoprecipitation (co-IP), pull-down, bacterial two-hybrid and saturation binding experiments, we showed that Atl binds directly to vimentin. CRISPR/Cas9-targeted deletion of vimentin in STECs (VIM KO STECs) abrogated the capacity of SS2 to translocate across the monolayers, SS2-induced phosphorylation of myosin II regulatory light chain (MLC) and MLCK transcription, indicating that vimentin is indispensable for MLCK activation. Consistently, vimentin null mice were protected from SS2 infection and exhibited reduced tracheal and lung injury. Thus, MLCK-mediated epithelial barrier opening caused by the Atl-vimentin interaction is found to be likely the key mechanism by which SS2 penetrates the tracheal epithelium.https://doi.org/10.1371/journal.ppat.1010765
spellingShingle Yu Meng
Qing Wang
Zhe Ma
Weiyi Li
Kai Niu
Ting Zhu
Huixing Lin
Chengping Lu
Hongjie Fan
Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.
PLoS Pathogens
title Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.
title_full Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.
title_fullStr Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.
title_full_unstemmed Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.
title_short Streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin.
title_sort streptococcal autolysin promotes dysfunction of swine tracheal epithelium by interacting with vimentin
url https://doi.org/10.1371/journal.ppat.1010765
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