Lectin–epithelial interactions in the human colon

Rhodes, Jonathan M.; Campbell, Barry J.; Yu, Lu‐Gang

doi:10.1042/bst0361482

Cited by 37 publications

(32 citation statements)

References 44 publications

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“…More recently, Fakhry et al (2009) observed that rod-shaped bacteria identified as B. breve bound tightly to the biopsied human ileal epithelium. Human cells, including gastro-intestinal epithelial cells, are known to express a variety of carbohydrate antigens (or lectin-binding sites) on their surface (Boland and Roberts 1988;Rhodes et al 2008). Meanwhile, mucins secreted from human intestinal epithelia are glycoproteins that also express various oligosaccharide structures branching off from their peptide stems.…”

Section: Discussionmentioning

confidence: 99%

Polymorphism and distribution of putative cell-surface adhesin-encoding ORFs among human fecal isolates of Bifidobacterium longum subsp. longum

Iguchi

Umekawa

Maegawa

et al. 2010

Antonie van Leeuwenhoek

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The polymorphism of ORFs encoding putative cell-surface adhesins was investigated in Bifidobacterium longum subsp. longum. Firstly, we performed a PCR assay targeting 15 ORFs encoding putative adhesion proteins, which included 8 ORFs with a sortase targeting LPXTG motif, in 42 strains of different pulsotypes isolated from fecal samples from 12 human individuals. We found a variability in the presence of an ORF, BL0675, which encodes a putative fimbrial subunit protein. We sequenced ORFs corresponding to BL0675 in the 42 strains and adjacent ORFs corresponding to BL0674 and BL0676. The results indicated that ORFs corresponding to BL0675 were highly polymorphic with five variant types (i.e. A-, B-, C-, D-, and E-types). Meanwhile, BL0674 and BL0676, which encode an additional putative fimbrial subunit protein and a fimbrial-associated sortase-like protein, were highly conserved. Subsequent quantitative polymerase chain reaction (qPCR) assays targeting the variant types in 89 human fecal samples revealed that A-type was the most commonly distributed (74.2%), followed by B-type (59.6%), D-type (31.5%), E-type (32.6%) and C-type (5.6% prevalence). Since BL0675 is considered to be a fimbrial protein with glycoprotein-binding ability, the proteins encoded by the five variant types of BL0675 may have specific binding properties to various carbohydrate structures expressed on the human intestinal wall, thereby allowing B. longum to colonize the intestine in a host-specific manner.

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Section: Discussionmentioning

confidence: 99%

Polymorphism and distribution of putative cell-surface adhesin-encoding ORFs among human fecal isolates of Bifidobacterium longum subsp. longum

Iguchi

Umekawa

Maegawa

et al. 2010

Antonie van Leeuwenhoek

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“…These include shortened oligosaccharide chain length, reduced sulphation, increased sialylation and increased expression of short oncofoetal carbohydrate antigens such as Thomsen-Friedenreich (TF) antigen (galactose β-1,3-N-acetylgalactosamine-α-Ser/Thr) and sialylTn (sialyl α-2,6- N-acetylgalactosamine-α-Ser/Thr) [reviewed in ref. [20]]. These changes are not unique to UC though and also occur in CD and in colon cancer and adenomatous as well as hyperplastic polyps.…”

Section: Alterations In the Mucosal Barrier In Inflammatory Bowel Dismentioning

confidence: 99%

Mucosal Barrier, Bacteria and Inflammatory Bowel Disease: Possibilities for Therapy

Merga

Campbell

Rhodes

2014

Dig Dis

156

113

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The mucosal barrier has three major components, the mucus layer, the epithelial glycocalyx and the surface epithelium itself, whose integrity largely depends on tight junction function. In health, there is relatively little direct interaction between the luminal microbiota and the epithelium - the continuous mucus layer in the colon keeps the surface epithelium out of contact with bacteria and the ileo-caecal valve ensures that the distal small intestine is relatively microbe free. Most interaction takes place at the Peyer's patches in the distal ileum and their smaller colonic equivalents, the lymphoid follicles. Peyer's patches are overlain by a ‘dome' epithelium, 5% of whose cells are specialised M (microfold) epithelial cells, which act as the major portal of entry for bacteria. There are no goblet cells in the dome epithelium and M cells have a very sparse glycocalyx allowing easy microbial interaction. It is intriguing that the typical age range for the onset of Crohn's disease (CD) is similar to the age at which the number of Peyer's patches is greatest. Peyer's patches are commonly the sites of the initial lesions in CD and the ‘anti-pancreatic' antibody associated with CD has been shown to have as its epitope the glycoprotein 2 that is the receptor for type-1 bacterial fimbrial protein (fimH) on M cells. There are many reasons to believe that the mucosal barrier is critically important in the pathogenesis of inflammatory bowel disease (IBD). These include (i) associations between both CD and ulcerative colitis (UC) with genes that are relevant to the mucosal barrier; (ii) increased intestinal permeability in unaffected relatives of CD patients; (iii) increased immune reactivity against bacterial antigens, and (iv) animal models in which altered mucosal barrier, e.g. denudation of the mucus layer associated with oral dextran sulphate in rodents, induces colitis. Whilst some IBD patients may have genetic factors leading to weakening of the mucosal barrier, it is likely that environmental factors may be even more important. Some may be subtle and indirect, e.g. the effects of stress on the mucosa barrier, whilst others may be more obvious, e.g. the effect of pathogen-related gastroenteritis, known often to act as trigger for IBD relapse. We have also been very interested in the potentially harmful effects of ingested detergents - either by contamination of cutlery by inadequate rinsing or via ingestion of processed foods containing permitted emulsifiers. In vitro and ex vivo studies show that even very small trace amounts of these surfactants can greatly increase bacterial translocation. Implications for therapy are not yet so obvious. We advise our IBD patients to avoid processed foods containing emulsifiers and to rinse their dishes well - whilst accepting that there is no direct evidence yet to support this. Therapies that aim to enhance the mucosal barrier have yet to come to market, but trials of enteric-delivered phosphatidylcholine in UC are promising. The faecal concentration of mucus-degrading bact...

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“…Alternatively, increased sialylation of TF antigen and of the more peripheral Lewis structures has been shown to be present in colon cancer metastases in comparison with primary tumours from the same individuals (Bresalier et al, 1996). There is increasing evidence that alterations of cancer-associated glycosylation may play an important regulatory role in cancer progression and development as a result of altered interaction of the cells with carbohydrate-binding lectins from endogenous as well as exogenous sources (Rhodes et al, 2008). Recent studies have shown that the increased expression of TF antigen on cancer-associated MUC1 allows binding of galectin-3 to the cancer cells (Khaldoyanidi et al, 2003;Yu et al, 2007).…”

Section: Disease-related Changes In Mucin and Mucosal Glycosylation Cmentioning

confidence: 99%

Glycosylation and Disease

Rhodes

Campbell

2010

Encyclopedia of Life Sciences

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Glycosylation is the process of attachment of sugar molecules, usually in chains (oligosaccharides), to proteins and lipids to form the glycoproteins and glycolipids found in eukaryotic and some prokaryotic organisms. The presence of oligosaccharides on a protein can have substantial effects on its size, stability, charge and antigenicity. The varying structure, branching and substitution of the carbohydrates in an oligosaccharide results in much greater diversity than would be achieved for a peptide with an equivalent number of residues. Acquired alterations in glycosylation occur in cancer and inflammation and may have particularly important functional consequences when they affect mucosae. They also have the potential to affect pathogen-host and other cell-cell interactions. Congenital glycosylation disorders most commonly affect N-glycosylation and affect development in diverse ways. There is increasing evidence of the importance of interactions between carbohydrate structures and carbohydrate-binding proteins (lectins) which may be extrinsic (dietary or microbial) or intrinsic (mammalian galectins or siglecs).

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Lectin–epithelial interactions in the human colon

Cited by 37 publications

References 44 publications

Polymorphism and distribution of putative cell-surface adhesin-encoding ORFs among human fecal isolates of Bifidobacterium longum subsp. longum

Polymorphism and distribution of putative cell-surface adhesin-encoding ORFs among human fecal isolates of Bifidobacterium longum subsp. longum

Mucosal Barrier, Bacteria and Inflammatory Bowel Disease: Possibilities for Therapy

Glycosylation and Disease

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