The Helicobacter pylori cytotoxin CagA is essential for suppressing host heat shock protein expression

Ben J. Lang, Rebecca J. Gorrell, Mona Tafreshi, Masanori Hatakeyama, Terry Kwok, John T. Price

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Bacterial infections typically elicit a strong Heat Shock Response (HSR) in host cells. However, the gastric pathogen Helicobacter pylori has the unique ability to repress this response, the mechanism of which has yet to be elucidated. This study sought to characterize the underlying mechanisms by which H. pylori down-modulates host HSP expression upon infection. Examination of isogenic mutant strains of H. pylori defective in components of the type IV secretion system (T4SS), identified the secretion substrate, CagA, to be essential for down-modulation of the HSPs HSPH1 (HSP105), HSPA1A (HSP72), and HSPD1 (HSP60) upon infection of the AGS gastric adenocarcinoma cell line. Ectopic expression of CagA by transient transfection was insufficient to repress HSP expression in AGS or HEK293T cells, suggesting that additional H. pylori factors are required for HSP repression. RT-qPCR analysis of HSP gene expression in AGS cells infected with wild-type H. pylori or isogenic cagA-deletion mutant found no significant change to account for reduced HSP levels. In summary, this study identified CagA to be an essential bacterial factor for H. pylori-mediated suppression of host HSP expression. The novel finding that HSPH1 is down-modulated by H. pylori further highlights the unique ability of H. pylori to repress the HSR within host cells. Elucidation of the mechanism by which H. pylori achieves HSP repression may prove to be beneficial in the identification of novel mechanisms to inhibit the HSR pathway and provide further insight into the interactions between H. pylori and the host gastric epithelium.
Original languageEnglish
Pages (from-to)523-533
Number of pages11
JournalCell Stress and Chaperones
Volume21
Issue number3
DOIs
Publication statusPublished - May 2016

Keywords

  • helicobacter pylori
  • CagA
  • heat shock proteins
  • heat shock response
  • gastric cancer

Cite this

@article{22a976e1e8264fcb803f49ff00a295d4,
title = "The Helicobacter pylori cytotoxin CagA is essential for suppressing host heat shock protein expression",
abstract = "Bacterial infections typically elicit a strong Heat Shock Response (HSR) in host cells. However, the gastric pathogen Helicobacter pylori has the unique ability to repress this response, the mechanism of which has yet to be elucidated. This study sought to characterize the underlying mechanisms by which H. pylori down-modulates host HSP expression upon infection. Examination of isogenic mutant strains of H. pylori defective in components of the type IV secretion system (T4SS), identified the secretion substrate, CagA, to be essential for down-modulation of the HSPs HSPH1 (HSP105), HSPA1A (HSP72), and HSPD1 (HSP60) upon infection of the AGS gastric adenocarcinoma cell line. Ectopic expression of CagA by transient transfection was insufficient to repress HSP expression in AGS or HEK293T cells, suggesting that additional H. pylori factors are required for HSP repression. RT-qPCR analysis of HSP gene expression in AGS cells infected with wild-type H. pylori or isogenic cagA-deletion mutant found no significant change to account for reduced HSP levels. In summary, this study identified CagA to be an essential bacterial factor for H. pylori-mediated suppression of host HSP expression. The novel finding that HSPH1 is down-modulated by H. pylori further highlights the unique ability of H. pylori to repress the HSR within host cells. Elucidation of the mechanism by which H. pylori achieves HSP repression may prove to be beneficial in the identification of novel mechanisms to inhibit the HSR pathway and provide further insight into the interactions between H. pylori and the host gastric epithelium.",
keywords = "helicobacter pylori, CagA, heat shock proteins, heat shock response, gastric cancer",
author = "Lang, {Ben J.} and Gorrell, {Rebecca J.} and Mona Tafreshi and Masanori Hatakeyama and Terry Kwok and Price, {John T.}",
year = "2016",
month = "5",
doi = "10.1007/s12192-016-0680-x",
language = "English",
volume = "21",
pages = "523--533",
journal = "Cell Stress and Chaperones",
issn = "1355-8145",
publisher = "Springer-Verlag London Ltd.",
number = "3",

}

The Helicobacter pylori cytotoxin CagA is essential for suppressing host heat shock protein expression. / Lang, Ben J.; Gorrell, Rebecca J.; Tafreshi, Mona; Hatakeyama, Masanori; Kwok, Terry; Price, John T.

In: Cell Stress and Chaperones, Vol. 21, No. 3, 05.2016, p. 523-533.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - The Helicobacter pylori cytotoxin CagA is essential for suppressing host heat shock protein expression

AU - Lang, Ben J.

AU - Gorrell, Rebecca J.

AU - Tafreshi, Mona

AU - Hatakeyama, Masanori

AU - Kwok, Terry

AU - Price, John T.

PY - 2016/5

Y1 - 2016/5

N2 - Bacterial infections typically elicit a strong Heat Shock Response (HSR) in host cells. However, the gastric pathogen Helicobacter pylori has the unique ability to repress this response, the mechanism of which has yet to be elucidated. This study sought to characterize the underlying mechanisms by which H. pylori down-modulates host HSP expression upon infection. Examination of isogenic mutant strains of H. pylori defective in components of the type IV secretion system (T4SS), identified the secretion substrate, CagA, to be essential for down-modulation of the HSPs HSPH1 (HSP105), HSPA1A (HSP72), and HSPD1 (HSP60) upon infection of the AGS gastric adenocarcinoma cell line. Ectopic expression of CagA by transient transfection was insufficient to repress HSP expression in AGS or HEK293T cells, suggesting that additional H. pylori factors are required for HSP repression. RT-qPCR analysis of HSP gene expression in AGS cells infected with wild-type H. pylori or isogenic cagA-deletion mutant found no significant change to account for reduced HSP levels. In summary, this study identified CagA to be an essential bacterial factor for H. pylori-mediated suppression of host HSP expression. The novel finding that HSPH1 is down-modulated by H. pylori further highlights the unique ability of H. pylori to repress the HSR within host cells. Elucidation of the mechanism by which H. pylori achieves HSP repression may prove to be beneficial in the identification of novel mechanisms to inhibit the HSR pathway and provide further insight into the interactions between H. pylori and the host gastric epithelium.

AB - Bacterial infections typically elicit a strong Heat Shock Response (HSR) in host cells. However, the gastric pathogen Helicobacter pylori has the unique ability to repress this response, the mechanism of which has yet to be elucidated. This study sought to characterize the underlying mechanisms by which H. pylori down-modulates host HSP expression upon infection. Examination of isogenic mutant strains of H. pylori defective in components of the type IV secretion system (T4SS), identified the secretion substrate, CagA, to be essential for down-modulation of the HSPs HSPH1 (HSP105), HSPA1A (HSP72), and HSPD1 (HSP60) upon infection of the AGS gastric adenocarcinoma cell line. Ectopic expression of CagA by transient transfection was insufficient to repress HSP expression in AGS or HEK293T cells, suggesting that additional H. pylori factors are required for HSP repression. RT-qPCR analysis of HSP gene expression in AGS cells infected with wild-type H. pylori or isogenic cagA-deletion mutant found no significant change to account for reduced HSP levels. In summary, this study identified CagA to be an essential bacterial factor for H. pylori-mediated suppression of host HSP expression. The novel finding that HSPH1 is down-modulated by H. pylori further highlights the unique ability of H. pylori to repress the HSR within host cells. Elucidation of the mechanism by which H. pylori achieves HSP repression may prove to be beneficial in the identification of novel mechanisms to inhibit the HSR pathway and provide further insight into the interactions between H. pylori and the host gastric epithelium.

KW - helicobacter pylori

KW - CagA

KW - heat shock proteins

KW - heat shock response

KW - gastric cancer

UR - http://www.ncbi.nlm.nih.gov/pubmed/26928021

U2 - 10.1007/s12192-016-0680-x

DO - 10.1007/s12192-016-0680-x

M3 - Article

VL - 21

SP - 523

EP - 533

JO - Cell Stress and Chaperones

JF - Cell Stress and Chaperones

SN - 1355-8145

IS - 3

ER -