Pseudomonas aeruginosa mucoid strain 8830 binds glycans containing the sialyl-Lewis x epitope

Abstract

Pseudomonas aeruginosa infection of patients with cystic fibrosis (CF) is a leading cause of their morbidity and mortality. Pathogenesis is initiated in part by molecular interactions of P. aeruginosa with carbohydrate residues in airway mucins that accumulate in the lungs of patients with this disease. To explore the nature of the glycans recognized by a stable, mucoid, alginate-producing strain P. aeruginosa 8830 we generated a genetically modified Pa8830 expressing green fluorescent protein (Pa3380-GFP). We tested its binding to a panel of glycolipids and neoglycolipids in which selected glycans were covalently attached to dipalmitoyl phosphatidylethanolamine and analyzed on silica gel surfaces. Among all glycans tested, Pa8830-GFP bound best to sialyl-Le(x)-containing glycan NeuAc(alpha2-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc-R and bound weakly to H-type blood group Fucalpha1-2Galbeta1-4GlcNAc-R, sialyl-lactose, and Le(x), and exhibited little binding toward non-fucosylated derivatives. Interestingly, while Pa8830-GFP bound to the glycosphingolipid asialoGM1, it did not appear to bind to a wide variety of other glycosphingolipids including GM1, GM2, asialoGM2, and sulfatide. These results indicate that P. aeruginosa 8830 has preferential binding to sialyl-Le(x)-containing glycans and has weak recognition of related fucose- and sialic acid-containing glycans. The finding that Pa8830 binds sialyl-Le(x)-containing glycans, which occur at increased levels in mucins from CF patients, is consistent with studies of other strains of P. aeruginosa and further suggests that such glycans on CF mucins contribute to disease pathogenesis.

Glycomic Analysis of Human Respiratory Tract Tissues and Correlation with Influenza Virus Infection

“…Greater insight of the role of such glycans is also coming from the development of a custom glycan microarray of sialylated poly-LacNAc containing N- and O- glycans as well as linear terminal fragments [16]. As bacteria such as Pseudomonas [17],and other respiratory viruses apart from influenza, such as parainfluenza utilize Sia in binding (reviewed in [18]), our glycan data will be beneficial in determining the potential tropism of these pathogens within the human respiratory tract.…”

Sialic acids in human health and disease

“…The link between these glycosylation differences and the changes in physical properties of the mucus have not been fully elucidated. In a related matter, the Pseudomonas strain that colonizes the airways in cystic fibrosis can use sialic acids as binding sites [130]. …”

Detection and characterization of a sialoglycosylated bacterial ABC-type phosphate transporter protein from patients with visceral leishmaniasis

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