Mechanism of action of EPEC Type III effector molecules

Kenny, Brendan

doi:10.1078/1438-4221-00155

Cited by 70 publications

(59 citation statements)

References 62 publications

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“…EPEC infect and colonize their hosts by way of a highly interactive process that is thought to involve three steps: initial non-intimate binding, signal transduction and then intimate adherence Delahay et al, 2001;Donnenberg and Whittam, 2001;Kenny, 2002;Campellone and Leong, 2003). The initial binding stage of the EPEC colonization process is also distinct from that of other enterovirulent E. coli and is characterized in typical strains by the formation of discrete microcolonies of EPEC on the host cell surface, a process known as localized adherence (LA).…”

Section: Introductionmentioning

confidence: 99%

The bundlin pilin protein of enteropathogenic Escherichia coli is an N-acetyllactosamine-specific lectin

et al. 2007

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SummarySynthetic N-acetyllactosamine (LacNAc) glycoside sequences coupled to BSA competitively inhibit enteropathogenic Escherichia coli (EPEC) localized adherence (LA) to human intestinal biopsy specimens and tissue culture cell monolayers. The LacNAcspecific adhesin appears to be associated with the bundle-forming pili (BFP) expressed by EPEC during the early stages of colonization. Herein, we report that recombinant bundlin inhibits EPEC LA to HEp-2 cells and binds to HEp-2 cells. Recombinant bundlin also binds, with millimolar association constants (K assoc), to synthetic LacNAc-Benzene and LacNAc-O(CH2)8CONH2 glycosides as assessed in the gas phase by nanoelectrospray ionization mass spectrometry. Furthermore, LacNAc-BSA inhibits LA only of EPEC strains that express a bundlin alleles, suggesting putative locations for the LacNAc-binding pocket in the a bundlin monomer. Collectively, these results suggest that a bundlin possesses lectin-like properties that are responsible for LacNAc-specific initial adherence of a bundlin-expressing EPEC strains to host intestinal epithelial cells.

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Section: Introductionmentioning

confidence: 99%

The bundlin pilin protein of enteropathogenic Escherichia coli is an N-acetyllactosamine-specific lectin

et al. 2007

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“…EPEC and EHEC deliver effector proteins into host cells via a type III secretion system (T3SS) encoded on a conserved pathogenicity island known as the locus of enterocyte effacement (LEE) (McDaniel et al 1995). The LEE is found in all A/E pathogens and is absolutely required for their pathogenesis (Kenny 2002). Encoded within the LEE are regulatory elements, seven secreted effectors and their related chaperones, as well as the T3SS apparatus itself (Frankel et al 1998b;Deng et al 2004).…”

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confidence: 99%

“…Encoded within the LEE are regulatory elements, seven secreted effectors and their related chaperones, as well as the T3SS apparatus itself (Frankel et al 1998b;Deng et al 2004). In addition to Tir, the T3SS translocates an assortment of effector proteins into host cells, which subvert cellular processes to promote A/E pathogen infection (Kenny 2002;Dean et al 2005;. To date, several LEE-encoded effectors, as well as a number of non-LEE (Nle)-encoded effectors , have been identified in the genomes of EPEC and EHEC (Tobe et al 2006;Coburn et al 2007;Iguchi et al 2009).…”

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confidence: 99%

In Vitro and In Vivo Model Systems for Studying Enteropathogenic Escherichia coli Infections

Law

Gur-Arie

Rosenshine

et al. 2013

Cold Spring Harbor Perspectives in Medicine

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Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) belong to a group of bacteria known as attaching and effacing (A/E) pathogens that cause disease by adhering to the lumenal surfaces of their host's intestinal epithelium. EPEC and EHEC are major causes of infectious diarrhea that result in significant childhood morbidity and mortality worldwide. Recent advances in in vitro and in vivo modeling of these pathogens have contributed to our knowledge of how EPEC and EHEC attach to host cells and subvert hostcell signaling pathways to promote infection and cause disease. A more detailed understanding of how these pathogenic microbes infect their hosts and how the host responds to infection could ultimately lead to new therapeutic strategies to help control these significant enteric pathogens.

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“…However, if bacterial genomes are subject to a continual ingress of novel DNA through horizontal gene transfer, the question is raised of how this DNA is removed from the genome should it cease to provide any selective advantage (33). Furthermore, some authors have questioned the utility of the pathogenicity island concept when in some cases the position, order, and clustering of virulence genes seem remarkably fluid (61).Many strains of EHEC and EPEC, like S. enterica, utilize type III secretion to subvert eukaryotic signaling pathways by injecting bacterial effector proteins into the host cell cytoplasm (27,30). Within these pathotypes of E. coli, a well-characterized type III secretion system (TTSS), similar to the Spi-2 system of S. enterica and encoded by a pathogenicity island termed the locus of enterocyte effacement (LEE), is responsible for the development of the attaching-effacing lesion and for other effects on enterocyte functions (21,30,37,38,48).…”

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confidence: 99%

“…Many strains of EHEC and EPEC, like S. enterica, utilize type III secretion to subvert eukaryotic signaling pathways by injecting bacterial effector proteins into the host cell cytoplasm (27,30). Within these pathotypes of E. coli, a well-characterized type III secretion system (TTSS), similar to the Spi-2 system of S. enterica and encoded by a pathogenicity island termed the locus of enterocyte effacement (LEE), is responsible for the development of the attaching-effacing lesion and for other effects on enterocyte functions (21,30,37,38,48).…”

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confidence: 99%

The ETT2 Gene Cluster, Encoding a Second Type III Secretion System from Escherichia coli , Is Present in the Majority of Strains but Has Undergone Widespread Mutational Attrition

et al. 2004

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ETT2 is a second cryptic type III secretion system in Escherichia coli which was first discovered through the analysis of genome sequences of enterohemorrhagic E. coli O157:H7. Comparative analyses of Escherichia and Shigella genome sequences revealed that the ETT2 gene cluster is larger than was previously thought, encompassing homologues of genes from the Spi-1, Spi-2, and Spi-3 Salmonella pathogenicity islands. ETT2-associated genes, including regulators and chaperones, were found at the same chromosomal location in the majority of genome-sequenced strains, including the laboratory strain K-12. Using a PCR-based approach, we constructed a complete tiling path through the ETT2 gene cluster for 79 strains, including the well-characterized E. coli reference collection supplemented with additional pathotypes. The ETT2 gene cluster was found to be present in whole or in part in the majority of E. coli strains, whether pathogenic or commensal, with patterns of distribution and deletion mirroring the known phylogenetic structure of the species. In almost all strains, including enterohemorrhagic E. coli O157:H7, ETT2 has been subjected to varying degrees of mutational attrition that render it unable to encode a functioning secretion system. A second type III secretion systemassociated locus that likely encodes the ETT2 translocation apparatus was found in some E. coli strains. Intact versions of both ETT2-related clusters are apparently present in enteroaggregative E. coli strain O42.The species Escherichia coli contains a wide range of commensal strains and pathogenic varieties (pathotypes) in addition to the model laboratory organism, E. coli K-12 (16). At least six pathotypes are associated with human intestinal disease: they are enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli, enteroaggregative E. coli (EAEC), and diffusely adherent E. coli. Two pathotypes are associated with extraintestinal disease in humans, namely uropathogenic E. coli (UPEC) and neonatal meningitic E. coli (NMEC). In addition, it is now clear that on phylogenetic grounds, all members of the genus Shigella belong within the species of E. coli (50). Furthermore, this dazzling phenotypic variety is matched by remarkable variations in genome size, with the largest E. coli genomes possessing more than a megabase more DNA than the smallest ones (43).Initial studies of UPEC, and later of other pathotypes, suggested that E. coli strains often acquire new complex pathogenic phenotypes in a single step by the acquisition of pathogenicity islands, which contain virulence genes clustered on the chromosome and which are acquired en bloc by horizontal gene transfer (21). Similar studies with the related bacterium Salmonella enterica have delineated several Salmonella pathogenicity islands (Spi-1, Spi-2, Spi-3, etc.) (2, 22). The horizontal transfer of DNA by mobile elements such as bacteriophages and plasmids is also known to play a role in the evolution of virulence in E. coli and S...

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Mechanism of action of EPEC Type III effector molecules

Cited by 70 publications

References 62 publications

The bundlin pilin protein of enteropathogenic Escherichia coli is an N-acetyllactosamine-specific lectin

The bundlin pilin protein of enteropathogenic Escherichia coli is an N-acetyllactosamine-specific lectin

In Vitro and In Vivo Model Systems for Studying Enteropathogenic Escherichia coli Infections

The ETT2 Gene Cluster, Encoding a Second Type III Secretion System from Escherichia coli , Is Present in the Majority of Strains but Has Undergone Widespread Mutational Attrition

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