Human glycan expression patterns influence Group A streptococcal colonization of epithelial cells

Abstract

Colonization of the oropharynx is the initial step in Group A Streptococcus (GAS) pharyngeal infection. We have previously reported that the highly virulent M1T1 GAS clone attaches to oral epithelial cells via M1 protein interaction with blood group antigen carbohydrate structures. Here, we have identified that colonization of human oral epithelial cells by GAS serotypes M3 and M12 is mediated by human blood group antigens [ABO(H)] and Lewis (Le) antigen expression. Removal of linkage‐specific fucose, galactose, N‐acetylgalactosamine, and sialic acid modulated GAS colonization, dependent on host ABO(H) blood group and Le expression profile. Furthermore, N‐linked glycans from human salivary glycoproteins, when released and purified, were potent inhibitors of M1, M3, and M12 GAS colonization ex vivo. These data highlight the important role played by human protein glycosylation patterns in GAS attachment to oral epithelial cell surfaces.—De Oliveira, D. M. P., Everest‐Dass, A., Hartley‐Tassell, L., Day, C. J., Indraratna, A., Brouwer, S., Cleary, A., Kautto, L., Gorman, J., Packer, N. H., Jennings, M. P., Walker, M. J., Sanderson‐Smith, M. L. Human glycan expression patterns influence Group A streptococcal colonization of epithelial cells. FASEB J. 33, 10808–10818 (2019). http://www.fasebj.org

Assessing the Role of Pharyngeal Cell Surface Glycans in Group A Streptococcus Biofilm Formation

“…Interactions of planktonic GAS with a variety of glycan structures have been observed in numerous studies, many of which indicate that host glycans are implicated in GAS binding and adhering to host cells [23][24][25]. In the current study, removal of N-linked glycans from the Detroit 562 pharyngeal cell surface significantly decreased initial adherence of planktonic M12 GAS.…”

“…The importance of terminal monosaccharides has been demonstrated in a previous study of GAS binding to human buccal epithelial (HBE) cells, whereby expression of terminal galactose and sialic acid residues had significant effects on M1, 3, and 12 associations, whilst terminal fucose and N-acetylgalactosamine were of comparatively lesser dependence of binding for all three GAS M-types. It was suggested that fucose and N-acetylgalactosamine may have a host-protective effect, sterically hindering access to the preferred galactose residues [25]. Many pathogens are known to possess their own suite of glycosidases which they utilize to liberate glycan residues for their own metabolic processes, and moreover, to better access preferred glycan structures for adherence [44,45].…”

“…GAS strains used in this study (see Supplementary Material, Table S2) are clinical GAS isolates, with each strain representative of a discrete GAS emm-type [25,[61][62][63][64]. GAS was grown on horse blood agar (HBA) plates (Edwards, Murarrie, Australia) or Todd Hewitt agar supplemented with 1% (w/v) yeast (THYA).…”

“…The plate was incubated for 2 h, 37 • C. Once incubated, the wells were washed once with PBS. Glycan removal was confirmed via lectin binding assay as per [25], with exoglycosidase pre-treated pharyngeal cell monolayers incubated with either biotinylated Hippeastrum hybrid lectin (binding mannose residues) (Vector Laboratories, Burlingame, CA, USA) or biotinylated Sambucus nigra lectin (binding sialic acid residues) (Vector Laboratories, Burlingame, CA, USA) (Supplementary Material 5, Figure S2).…”

The exploitation of human glycans by Group AStreptococcus

“…1 ) (De Oliveira et al . 2019 ). The M protein-expressing GAS strains were shown to preferentially associate with HBE cells expressing H-antigen.…”