scholarly journals ALPK1 and TIFA dependent innate immune response triggered by the Helicobacter pylori type IV secretion system

2017 ◽  
Author(s):  
Stephanie Zimmermann ◽  
Lennart Pfannkuch ◽  
Munir A. Al-Zeer ◽  
Sina Bartfeld ◽  
Manuel Koch ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Protein Translocation ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Innate Immune ◽  
Host Cells ◽  
Cell Contact ◽  
Type Iv Secretion System ◽  
Type Iv ◽  
H Pylori

SummaryActivation of transcription factor NF-κB is a hallmark of infection with the gastric pathogen Helicobacter pylori and associated with inflammation and carcinogenesis. Genome-wide RNAi screening revealed numerous hits involved in H. pylori-, but not IL-1β- and TNF-α- dependent NF-κB regulation. Pathway analysis including CRISPR/Cas9-knockout and recombinant protein technology, immunofluorescence microscopy, immunoblotting, mass spectrometry and mutant H. pylori strains, identified the H. pylori metabolite D-glycero-β-D-manno-heptose 1,7-bisphosphate (βHBP) as a cagPAI type IV secretion system (T4SS)-dependent effector of NF-κB activation in infected cells. Upon pathogen-host cell contact, TIFA forms large complexes (TIFAsomes) including interacting host factors, such as TRAF2. NF-κB activation, TIFA phosphorylation as well as TIFAsome formation depended on a functional ALPK1 kinase, highlighting the ALPK1-TIFA axis as core of a novel innate immune pathway. ALPK1-TIFA-mediated NF-κB activation was independent of CagA protein translocation, indicating that CagA translocation and HBP delivery to host cells are distinct features of the pathogen’s T4SS.

scholarly journals Cryo-EM reveals species-specific components within the Helicobacter pylori Cag type IV secretion system core complex

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Michael J Sheedlo ◽  
Jeong Min Chung ◽  
Neha Sawhney ◽  
Clarissa L Durie ◽  
Timothy L Cover ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Host Cells ◽  
Molar Ratio ◽  
Type Iv Secretion System ◽  
Core Complex ◽  
Type Iv ◽  
H Pylori ◽  
Species Specific

The pathogenesis of Helicobacter pylori-associated gastric cancer is dependent on delivery of CagA into host cells through a type IV secretion system (T4SS). The H. pylori Cag T4SS includes a large membrane-spanning core complex containing five proteins, organized into an outer membrane cap (OMC), a periplasmic ring (PR) and a stalk. Here, we report cryo-EM reconstructions of a core complex lacking Cag3 and an improved map of the wild-type complex. We define the structures of two unique species-specific components (Cag3 and CagM) and show that Cag3 is structurally similar to CagT. Unexpectedly, components of the OMC are organized in a 1:1:2:2:5 molar ratio (CagY:CagX:CagT:CagM:Cag3). CagX and CagY are components of both the OMC and the PR and bridge the symmetry mismatch between these regions. These results reveal that assembly of the H. pylori T4SS core complex is dependent on incorporation of interwoven species-specific components.

scholarly journals Cryo-EM reveals species-specific components within the Helicobacter pylori Cag type IV secretion system core complex

2020 ◽  
Author(s):  
Michael J. Sheedlo ◽  
Jeong Min Chung ◽  
Neha Sawhney ◽  
Clarissa L. Durie ◽  
Timothy L. Cover ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Host Cells ◽  
Molar Ratio ◽  
Type Iv Secretion System ◽  
Core Complex ◽  
Type Iv ◽  
H Pylori ◽  
Species Specific

AbstractThe pathogenesis of Helicobacter pylori-associated gastric cancer is dependent on delivery of CagA into host cells through a type IV secretion system (T4SS). The H. pylori Cag T4SS includes a large membrane-spanning core complex containing 5 proteins, organized into an outer membrane cap (OMC), a periplasmic ring (PR) and a stalk. Here, we report cryo-EM reconstructions of a core complex lacking Cag3 and an improved map of the wild-type complex. We define the structures of two unique species-specific components (Cag3 and CagM) and show that Cag3 is structurally similar to CagT. Unexpectedly, components of the OMC are organized in a 1:1:2:2:5 molar ratio (CagY:CagX:CagT:CagM:Cag3). CagX and CagY are components of both the OMC and the PR and bridge the symmetry mismatch between these regions. These results reveal that assembly of the H. pylori T4SS core complex is dependent on incorporation of interwoven species-specific components.

The innate immune glycoprotein lactoferrin represses the Helicobacter pylori cag type IV secretion system

ChemBioChem ◽  
2021 ◽  
Author(s):  
Jacky Lu ◽  
Kathryn Haley ◽  
Jamisha Francis ◽  
Miriam Guevara ◽  
Ryan Doster ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Innate Immune ◽  
Type Iv Secretion System ◽  
Type Iv

scholarly journals ALPK1- and TIFA-Dependent Innate Immune Response Triggered by the Helicobacter pylori Type IV Secretion System

Cell Reports ◽  
2017 ◽  
Vol 20 (10) ◽  
pp. 2384-2395 ◽  
Author(s):  
Stephanie Zimmermann ◽  
Lennart Pfannkuch ◽  
Munir A. Al-Zeer ◽  
Sina Bartfeld ◽  
Manuel Koch ◽  
...  
Keyword(s):  
Immune Response ◽  
Helicobacter Pylori ◽  
Innate Immune Response ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Innate Immune ◽  
Type Iv Secretion System ◽  
Type Iv

scholarly journals Protein-Protein Interactions among Helicobacter pylori Cag Proteins

2006 ◽  
Vol 188 (13) ◽  
pp. 4787-4800 ◽  
Author(s):  
Valerie J. Busler ◽  
Victor J. Torres ◽  
Mark S. McClain ◽  
Oscar Tirado ◽  
David B. Friedman ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Protein Interactions ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Type Iv Secretion System ◽  
Protein Protein Interactions ◽  
Chromosomal Dna ◽  
2D Dige ◽  
Type Iv ◽  
H Pylori

ABSTRACT Many Helicobacter pylori isolates contain a 40-kb region of chromosomal DNA known as the cag pathogenicity island (PAI). The risk for development of gastric cancer or peptic ulcer disease is higher among humans infected with cag PAI-positive H. pylori strains than among those infected with cag PAI-negative strains. The cag PAI encodes a type IV secretion system that translocates CagA into gastric epithelial cells. To identify Cag proteins that are expressed by H. pylori during growth in vitro, we compared the proteomes of a wild-type H. pylori strain and an isogenic cag PAI deletion mutant using two-dimensional difference gel electrophoresis (2D-DIGE) in multiple pH ranges. Seven Cag proteins were identified by this approach. We then used a yeast two-hybrid system to detect potential protein-protein interactions among 14 Cag proteins. One heterotypic interaction (CagY/7 with CagX/8) and two homotypic interactions (involving H. pylori VirB11/ATPase and Cag5) were similar to interactions previously reported to occur among homologous components of the Agrobacterium tumefaciens type IV secretion system. Other interactions involved Cag proteins that do not have known homologues in other bacterial species. Biochemical analysis confirmed selected interactions involving five of the proteins that were identified by 2D-DIGE. Protein-protein interactions among Cag proteins are likely to have an important role in the assembly of the H. pylori type IV secretion apparatus.

scholarly journals Analysis of Cell Type-Specific Responses Mediated by the Type IV Secretion System of Helicobacter pylori

2005 ◽  
Vol 73 (8) ◽  
pp. 4643-4652 ◽  
Author(s):  
Bianca Bauer ◽  
Stefan Moese ◽  
Sina Bartfeld ◽  
Thomas F. Meyer ◽  
Matthias Selbach
Keyword(s):  
Helicobacter Pylori ◽  
Host Cell ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Type Iv Secretion System ◽  
Type Iv ◽  
Host Cell Proteins ◽  
Mammalian Cell Lines ◽  
Host Cell Factors ◽  
H Pylori

ABSTRACT Helicobacter pylori persistently infects the human stomach and can cause gastritis, gastric ulceration, and gastric cancer. The type IV secretion system (TFSS) of virulent H. pylori strains translocates the CagA protein, inducing the dephosphorylation of host cell proteins and leading to changes in the morphology or shape of AGS gastric epithelial cells. Furthermore, the TFSS is involved in the induction of proinflammatory cytokines. While the H. pylori genes required for TFSS function have been investigated systematically, little is known about possible host cell factors involved. We infected 19 different mammalian cell lines individually with H. pylori and analyzed CagA translocation, dephosphorylation of host cell proteins, chemokine secretion (interleukin-8 and macrophage inflammatory protein 2), and changes in cellular phenotypes. Our results demonstrate that not only bacterial but also host cell factors determine the cellular response to infection. The identification of such unknown host cell factors will add to our understanding of host-pathogen interactions and might help in the development of new therapeutic strategies.

ALPK1 and TIFA Dependent Innate Immune Response Triggered by the Helicobacter pylori Type IV Secretion System

2018 ◽  
Author(s):  
Stephanie Zimmermann ◽  
Lennart Pfannkuch ◽  
Munir A. Al-Zeer ◽  
Sina Bartfeld ◽  
Manuel Koch ◽  
...  
Keyword(s):  
Immune Response ◽  
Helicobacter Pylori ◽  
Innate Immune Response ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Innate Immune ◽  
Type Iv Secretion System ◽  
Type Iv

scholarly journals In vivostructures of theHelicobacter pylori cagtype IV secretion system

2017 ◽  
Author(s):  
Yi-Wei Chang ◽  
Carrie L. Shaffer ◽  
Lee A. Rettberg ◽  
Debnath Ghosal ◽  
Grant J. Jensen
Keyword(s):  
Secretion System ◽  
Type Iv Secretion ◽  
Host Cells ◽  
Type Iv Secretion System ◽  
Molecular Architecture ◽  
Type Iv ◽  
H Pylori ◽  
Electron Cryotomography ◽  
Rod Structures ◽  
Bacterial Type

SummaryThe bacterial type IV secretion system (T4SS) is a versatile nanomachine that translocates diverse effector molecules between microbes and into eukaryotic cells. Using electron cryotomography, here we reveal the molecular architecture of the cancer-associatedHelicobacter pylori cagT4SS. Although most components are unique toH. pylori, thecagT4SS exhibits remarkable architectural similarity to previously studied T4SSs. WhenH. pyloriencounters host cells, however, the bacterium elaborates rigid, membranous tubes perforated by lateral ports. Dense, pilus-like rod structures extending from the inner membrane were also observed. We propose that the membrane tubes assemble out of the T4SS and are the delivery system forcagT4SS cargo. These studies reveal the architecture of a dynamic molecular machine that evolved to function in the human gastric niche.

scholarly journals Maintenance of Type IV Secretion Function During Helicobacter pylori Infection in Mice

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. e03147-20
Author(s):  
Emma C. Skoog ◽  
Miriam E. Martin ◽  
Roberto M. Barrozo ◽  
Lori M. Hansen ◽  
Lucy P. Cai ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Murine Model ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Type Iv Secretion System ◽  
Content Type ◽  
Biologically Relevant ◽  
Type Iv ◽  
H Pylori

ABSTRACTThe Helicobacter pylori type IV secretion system (T4SS) encoded on the cag pathogenicity island (cagPAI) secretes the CagA oncoprotein and other effectors into the gastric epithelium. During murine infection, T4SS function is lost in an immune-dependent manner, typically as a result of in-frame recombination in the middle repeat region of cagY, though single nucleotide polymorphisms (SNPs) in cagY or in other essential genes may also occur. Loss of T4SS function also occurs in gerbils, nonhuman primates, and humans, suggesting that it is biologically relevant and not simply an artifact of the murine model. Here, we sought to identify physiologically relevant conditions under which T4SS function is maintained in the murine model. We found that loss of H. pylori T4SS function in mice was blunted by systemic Salmonella coinfection and completely eliminated by dietary iron restriction. Both have epidemiologic parallels in humans, since H. pylori strains from individuals in developing countries, where iron deficiency and systemic infections are common, are also more often cagPAI+ than strains from developed countries. These results have implications for our fundamental understanding of the cagPAI and also provide experimental tools that permit the study of T4SS function in the murine model.IMPORTANCE The type IV secretion system (T4SS) is the major Helicobacter pylori virulence factor, though its function is lost during murine infection. Loss of function also occurs in gerbils and in humans, suggesting that it is biologically relevant, but the conditions under which T4SS regulation occurs are unknown. Here, we found that systemic coinfection with Salmonella and iron deprivation each promote retention of T4SS function. These results improve our understanding of the cag pathogenicity island (cagPAI) and provide experimental tools that permit the study of T4SS function in the murine model.

scholarly journals The Innate Immune Glycoprotein Lactoferrin Represses the Helicobacter pylori cag Type IV Secretion System

ChemBioChem ◽  
2021 ◽  
Author(s):  
Jacky Lu ◽  
Kathryn P. Haley ◽  
Jamisha D. Francis ◽  
Miriam A. Guevara ◽  
Ryan S. Doster ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Innate Immune ◽  
Type Iv Secretion System ◽  
Type Iv
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