Glycoconjugates Play a Key Role in Campylobacter jejuni Infection: Interactions between Host and Pathogen

Abstract

Glycan based interactions between host and pathogen are critical in many bacterial and viral diseases. Glycan interactions range from initial receptor based adherence to protecting the infective agent from the host’s immune response through molecular mimicry. Campylobacter jejuni is an ideal model for studying the role of glycans in host–pathogen interactions, as well as the role of bacterial surface glycoconjugates in infection. Using glycan array analysis, C. jejuni has been shown to interact with a wide range of host glycoconjugates. Mannose and sialic acid residues appear to play a role in initial interactions between host and pathogen following environmental exposure, whereas fucose and galactose based interactions are likely to be required for prolonged colonization. Other studies have highlighted potential decoy receptor type interactions between host’s intestinal mucins and C. jejuni, demonstrating the importance of host glycoproteins as defense against C. jejuni infection as well as the role for glycoconjugates found in human breast milk in protection of breast feeding infants from infection with C. jejuni. C. jejuni can produce N- and O-linked glycoproteins, capsular polysaccharide (CPS) and/or lipooligosaccharide (LOS) which results in C. jejuni presenting its own diverse sugar coated displays on the cell surface. Bacterial glycans play an important and versatile role in infection and disease. Of these, the best understood is the molecular mimicry of human gangliosides presented by C. jejuni’s LOS and its link to the onset of autoimmune neuropathies such as the Guillain Barrè syndrome (GBS). However, the role of glycoconjugates presented by C. jejuni extends beyond expression of sialylated ganglioside structures involved in initiation of GBS. Expression of surface glycans by C. jejuni may also relate to the ability of this organism to interact with the glycoproteins for initial host–pathogen interactions and continued infectivity.

Insights into bacterial protein glycosylation in human microbiota

“…Since the glycosylation of flagella has been reviewed recently (Tytgat and Lebeer, 2014), we will not expand on this topic. C. jejuni harbors both O- and N-linked glycosylation system, each has a dedicated gene cluster to catalyze the modification (Day et al, 2012; Guerry and Szymanski, 2008; Szymanski et al, 2003). In addition to flagella, there are a number of surface glycoproteins in C. jejuni that play important roles in bacterial attachment to host cells.…”

Cell surface‐associated aggregation‐promoting factor from Lactobacillus gasseri SBT2055 facilitates host colonization and competitive exclusion of Campylobacter jejuni

“…Although this conclusion is supported by the results of a C. jejuni inhibition assay using anti‐fibronectin antibody (http://onlinelibrary.wiley.com/doi/10.1111/mmi.13153/suppinfo), the inhibitory effect was more efficient following treatment with GST‐APF1 or APF1‐expressing LG2055. APF1 shows weak binding to laminin and mucin, which is targeted by C. jejuni colonization (Kuusela et al ., ; Day et al ., ). These interactions possibly contribute to the strong avidity of bacterial cells for intestinal mucosal surfaces and could also further enhance the APF1‐mediated inhibitory effect.…”

“…S11), the inhibitory effect was more efficient following treatment with GST-APF1 or APF1-expressing LG2055. APF1 shows weak binding to laminin and mucin, which is targeted by C. jejuni colonization (Kuusela et al, 1989;Day et al, 2012). These interactions possibly contribute to the strong avidity of bacterial cells for intestinal mucosal surfaces and could also further enhance the APF1-mediated inhibitory effect.…”

The Challenge and Promise of Glycomics

“…Moreover, pathogens, such as Vibrio cholera , Shigella dysenteriae , and Clostridium tetani , all secrete toxins that bind specific GSL on cell surfaces. A discussion of microbial proteins that recognize cell surface GSL and other types of glycans can be found in Essentials of Glycobiology, Chapter 28 and other sources (Day et al, 2012; Karlsson, 1989; Topin et al, 2013). …”