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Sialyl-Le(x) and sulfo-sialyl-Le(x) determinants are receptors for P. aeruginosa
A Scharfman1, P Delmotte, J Beau
1Unité INSERM n377 and Université de Lille 2, France.
Abstract:
Pseudomonas aeruginosa, the main pathogen in the airways of patients suffering from cystic fibrosis (CF), binds to carbohydrate chains of respiratory mucins. Using flow cytometry and polyacrylamide based fluorescent glycoconjugates, it was previously demonstrated that several strains of P. aeruginosa recognize a set of neutral and acidic carbohydrate epitopes found at the periphery of respiratory mucins, especially sialyl-Le(x). This structure, overexpressed in mucins from CF patients, could be responsible in part for the persistence of lung infection in CF patients. The aim of the present work was to determine whether a glycoconjugate bearing the 6-sulfo-sialyl-Le(x) epitope, also found in abundance in CF airway mucins, is also preferentially recognised by different strains of P. aeruginosa. The study was conducted with a nonpiliated strain 1244-NP and four mucoid strains isolated from CF patients. For four strains out of five, the affinity for 6-sulfo-sialyl-Le(x) was as high as for sialyl-Le(x) derivative. These results were confirmed for strain 1244-NP by a microtiter plate assay.
Insights
Pseudomonas aeruginosa, a key pathogen in cystic fibrosis (CF) lung infections, preferentially binds to the 6-sulfo-sialyl-Le(x) carbohydrate epitope in CF airway mucins. This finding may explain persistent bacterial infections in CF patients.
Area of Science:
- Microbiology
- Glycobiology
- Infectious Diseases
Background:
- Pseudomonas aeruginosa is a primary pathogen in cystic fibrosis (CF) airways.
- P. aeruginosa binds to respiratory mucins, particularly recognizing sialyl-Le(x) epitopes.
- Sialyl-Le(x) is overexpressed in CF mucins and may contribute to persistent lung infections.
Purpose of the Study:
- To investigate if P. aeruginosa strains preferentially recognize the 6-sulfo-sialyl-Le(x) epitope.
- To assess the binding affinity of P. aeruginosa to 6-sulfo-sialyl-Le(x) found in CF airway mucins.
Main Methods:
- Utilized flow cytometry and fluorescent glycoconjugates.
- Tested a nonpiliated strain (1244-NP) and four mucoid P. aeruginosa strains from CF patients.
- Employed a microtiter plate assay for confirmation.
Main Results:
- Four out of five P. aeruginosa strains showed high affinity for 6-sulfo-sialyl-Le(x).
- The binding affinity for 6-sulfo-sialyl-Le(x) was comparable to that of sialyl-Le(x).
- Results were validated using a microtiter plate assay for strain 1244-NP.
Conclusions:
- P. aeruginosa demonstrates a strong preference for the 6-sulfo-sialyl-Le(x) epitope in CF airway mucins.
- This recognition may play a significant role in the pathogenesis of P. aeruginosa infections in cystic fibrosis.
- Further research into this interaction could inform novel therapeutic strategies.