Burkholderia cenocepacia J2315 escapes to the cytosol and actively subverts autophagy in human macrophages

Souhaila M. Al Khodor, Kimberly Marshall-Batty, Vinod Nair, Li Ding, David E. Greenberg, Iain D C Fraser

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Selective autophagy functions to specifically degrade cellular cargo tagged by ubiquitination, including bacteria. Strains of the Burkholderia cepacia complex (Bcc) are opportunistic pathogens that cause life-threatening infections in patients with cystic fibrosis (CF) and chronic granulomatous disease (CGD). While there is evidence that defective macrophage autophagy in a mouse model of CF can influence B.cenocepacia susceptibility, there have been no comprehensive studies on how this bacterium is sensed and targeted by the host autophagy response in human macrophages. Here, we describe the intracellular life cycle of B.cenocepaciaJ2315 and its interaction with the autophagy pathway in human cells. Electron and confocal microscopy analyses demonstrate that the invading bacteria interact transiently with the endocytic pathway before escaping to the cytosol. This escape triggers theselective autophagy pathway, and the recruitment of ubiquitin, the ubiquitin-binding adaptors p62 and NDP52 and the autophagosome membrane-associated protein LC3B, to the bacterial vicinity. However, despite recruitment of these key autophagy pathway effectors, B.cenocepacia blocks autophagosome completion and replicates in the host cytosol. We find that a pre-infection increase in cellular autophagy flux can significantly inhibit B.cenocepacia replication and that lower autophagy flux in macrophages from immunocompromised CGD patients could contribute to increased B.cenocepacia susceptibility, identifying autophagy manipulation as a potential therapeutic approach to reduce bacterial burden in B.cenocepacia infections. Published 2013. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Original languageEnglish
Pages (from-to)378-395
Number of pages18
JournalCellular Microbiology
Volume16
Issue number3
DOIs
Publication statusPublished - Mar 2014
Externally publishedYes

Fingerprint

Burkholderia cenocepacia
Autophagy
Cytosol
Macrophages
Chronic Granulomatous Disease
Ubiquitin
Bacteria
Cystic Fibrosis
Burkholderia cepacia complex
Infection
Public Sector
Ubiquitination
Life Cycle Stages
Confocal Microscopy
Electron Microscopy
Membrane Proteins

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Virology

Cite this

Burkholderia cenocepacia J2315 escapes to the cytosol and actively subverts autophagy in human macrophages. / Al Khodor, Souhaila M.; Marshall-Batty, Kimberly; Nair, Vinod; Ding, Li; Greenberg, David E.; Fraser, Iain D C.

In: Cellular Microbiology, Vol. 16, No. 3, 03.2014, p. 378-395.

Research output: Contribution to journalArticle

Al Khodor, Souhaila M. ; Marshall-Batty, Kimberly ; Nair, Vinod ; Ding, Li ; Greenberg, David E. ; Fraser, Iain D C. / Burkholderia cenocepacia J2315 escapes to the cytosol and actively subverts autophagy in human macrophages. In: Cellular Microbiology. 2014 ; Vol. 16, No. 3. pp. 378-395.
@article{e62438c307cb47f8ba38adfb1b5f4268,
title = "Burkholderia cenocepacia J2315 escapes to the cytosol and actively subverts autophagy in human macrophages",
abstract = "Selective autophagy functions to specifically degrade cellular cargo tagged by ubiquitination, including bacteria. Strains of the Burkholderia cepacia complex (Bcc) are opportunistic pathogens that cause life-threatening infections in patients with cystic fibrosis (CF) and chronic granulomatous disease (CGD). While there is evidence that defective macrophage autophagy in a mouse model of CF can influence B.cenocepacia susceptibility, there have been no comprehensive studies on how this bacterium is sensed and targeted by the host autophagy response in human macrophages. Here, we describe the intracellular life cycle of B.cenocepaciaJ2315 and its interaction with the autophagy pathway in human cells. Electron and confocal microscopy analyses demonstrate that the invading bacteria interact transiently with the endocytic pathway before escaping to the cytosol. This escape triggers theselective autophagy pathway, and the recruitment of ubiquitin, the ubiquitin-binding adaptors p62 and NDP52 and the autophagosome membrane-associated protein LC3B, to the bacterial vicinity. However, despite recruitment of these key autophagy pathway effectors, B.cenocepacia blocks autophagosome completion and replicates in the host cytosol. We find that a pre-infection increase in cellular autophagy flux can significantly inhibit B.cenocepacia replication and that lower autophagy flux in macrophages from immunocompromised CGD patients could contribute to increased B.cenocepacia susceptibility, identifying autophagy manipulation as a potential therapeutic approach to reduce bacterial burden in B.cenocepacia infections. Published 2013. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.",
author = "{Al Khodor}, {Souhaila M.} and Kimberly Marshall-Batty and Vinod Nair and Li Ding and Greenberg, {David E.} and Fraser, {Iain D C}",
year = "2014",
month = "3",
doi = "10.1111/cmi.12223",
language = "English",
volume = "16",
pages = "378--395",
journal = "Cellular Microbiology",
issn = "1462-5814",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Burkholderia cenocepacia J2315 escapes to the cytosol and actively subverts autophagy in human macrophages

AU - Al Khodor, Souhaila M.

AU - Marshall-Batty, Kimberly

AU - Nair, Vinod

AU - Ding, Li

AU - Greenberg, David E.

AU - Fraser, Iain D C

PY - 2014/3

Y1 - 2014/3

N2 - Selective autophagy functions to specifically degrade cellular cargo tagged by ubiquitination, including bacteria. Strains of the Burkholderia cepacia complex (Bcc) are opportunistic pathogens that cause life-threatening infections in patients with cystic fibrosis (CF) and chronic granulomatous disease (CGD). While there is evidence that defective macrophage autophagy in a mouse model of CF can influence B.cenocepacia susceptibility, there have been no comprehensive studies on how this bacterium is sensed and targeted by the host autophagy response in human macrophages. Here, we describe the intracellular life cycle of B.cenocepaciaJ2315 and its interaction with the autophagy pathway in human cells. Electron and confocal microscopy analyses demonstrate that the invading bacteria interact transiently with the endocytic pathway before escaping to the cytosol. This escape triggers theselective autophagy pathway, and the recruitment of ubiquitin, the ubiquitin-binding adaptors p62 and NDP52 and the autophagosome membrane-associated protein LC3B, to the bacterial vicinity. However, despite recruitment of these key autophagy pathway effectors, B.cenocepacia blocks autophagosome completion and replicates in the host cytosol. We find that a pre-infection increase in cellular autophagy flux can significantly inhibit B.cenocepacia replication and that lower autophagy flux in macrophages from immunocompromised CGD patients could contribute to increased B.cenocepacia susceptibility, identifying autophagy manipulation as a potential therapeutic approach to reduce bacterial burden in B.cenocepacia infections. Published 2013. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

AB - Selective autophagy functions to specifically degrade cellular cargo tagged by ubiquitination, including bacteria. Strains of the Burkholderia cepacia complex (Bcc) are opportunistic pathogens that cause life-threatening infections in patients with cystic fibrosis (CF) and chronic granulomatous disease (CGD). While there is evidence that defective macrophage autophagy in a mouse model of CF can influence B.cenocepacia susceptibility, there have been no comprehensive studies on how this bacterium is sensed and targeted by the host autophagy response in human macrophages. Here, we describe the intracellular life cycle of B.cenocepaciaJ2315 and its interaction with the autophagy pathway in human cells. Electron and confocal microscopy analyses demonstrate that the invading bacteria interact transiently with the endocytic pathway before escaping to the cytosol. This escape triggers theselective autophagy pathway, and the recruitment of ubiquitin, the ubiquitin-binding adaptors p62 and NDP52 and the autophagosome membrane-associated protein LC3B, to the bacterial vicinity. However, despite recruitment of these key autophagy pathway effectors, B.cenocepacia blocks autophagosome completion and replicates in the host cytosol. We find that a pre-infection increase in cellular autophagy flux can significantly inhibit B.cenocepacia replication and that lower autophagy flux in macrophages from immunocompromised CGD patients could contribute to increased B.cenocepacia susceptibility, identifying autophagy manipulation as a potential therapeutic approach to reduce bacterial burden in B.cenocepacia infections. Published 2013. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

UR - http://www.scopus.com/inward/record.url?scp=84893855880&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84893855880&partnerID=8YFLogxK

U2 - 10.1111/cmi.12223

DO - 10.1111/cmi.12223

M3 - Article

VL - 16

SP - 378

EP - 395

JO - Cellular Microbiology

JF - Cellular Microbiology

SN - 1462-5814

IS - 3

ER -