Perlecan in the basement membrane of corneal epithelium serves as a site for P. aeruginosa binding.
OBJECTIVE
To determine whether binding of Pseudomonas aeruginosa (P. aeruginosa) to the scarified mouse cornea depends on interaction with proteoglycans (PGs).


METHODS
Scarified corneas were treated with anti-proteoglycan monoclonal antibodies (MAbs), glycosaminoglycans (GAGs), heparinase III or chondroitin ABC lyase before inoculation with P. aeruginosa strain ATCC 19660 or PAO1. Scanning electron microscopy (SEM) was used to quantitate adherent bacteria. Frozen sections of unwounded and wounded mouse cornea, the latter treated or not treated with heparinase III were stained to spatially localize perlecan [core protein or heparan sulfate (HS) side chains]. Anti-perlecan MAb against the heparan sulfate proteoglycan core protein and succinyl wheat germ agglutinin (sWGA), a lectin which recognizes N-acetyl-glucosamine in heparan sulfate, respectively were used.


RESULTS
Anti-perlecan MAb, as well as heparan sulfate, heparin and heparinase III decreased the binding of both bacterial strains to cornea, and the decrease was concentration-dependent. Fluorescence microscopic analysis of sections of mouse cornea immunostained with anti-perlecan MAb showed that perlecan was localized to the epithelial basement membrane. Scarification of the mouse cornea exposed perlecan in the basement membrane and increased bacterial binding to this site was consistent with this exposure. Lectin staining revealed that heparinase treatment removed heparan sulfate side chains of perlecan from the exposed basement membrane, and this removal was consistent with a decrease in bacterial binding.


CONCLUSIONS
These studies provide evidence that perlecan, core protein and its heparan sulfate side chains serve as a binding site for Pseudomonas aeruginosa when the basement membrane of the cornea is exposed.
Chen
L D
LD
Department of Anatomy/Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA.
Hazlett
L D
LD
D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology; D001485:Basement Membrane / Q000378:metabolism* / Q000382:microbiology*; D019765:Chondroitin ABC Lyase / Q000494:pharmacology; D003315:Cornea / Q000378:metabolism* / Q000382:microbiology*; D004848:Epithelium / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology; D006497:Heparan Sulfate / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D011133:Polysaccharide-Lyases / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000502:physiology*; D013194:Staining and Labeling; D014909:Wheat Germ Agglutinins
D019765:Chondroitin ABC Lyase; D019812:Heparan Sulfate Proteoglycans; D006493:Heparin; D006497:Heparan Sulfate; D011133:Polysaccharide-Lyases; D014909:Wheat Germ Agglutinins; C030717:succinylated wheat germ agglutinin; C071927:perlecan; C021349:heparitinsulfate lyase