A novel mechanism of increased infections in contact lens wearers.
OBJECTIVE
It is well documented that contact lens wearers have much higher incidences of corneal infections compared with those of non-contact lens wearers, although the exact cause(s) of this increased susceptibility has not been identified. A distinct subset of mucins (MUCs) is present on the ocular surface, acting to protect the integrity of the corneal epithelium. This study was performed to determine whether multipurpose contact lens solutions (MPCLSs) can cause increased infections in the cornea by destroying the protective cell-bound mucin layer.


METHODS
An immortalized human corneal limbal epithelial cell line was treated in the presence of four commonly used MPCLSs or PBS and the expression and release of MUC-16 was assessed. Cells were also cultured with Pseudomonas aeruginosa after MPCLS treatment and internalization of bacteria was assessed by quantitative genomic PCR. Loss of MUC-16 was then correlated with infection rates.


RESULTS
Each of the four commonly used MPCLSs examined in this study differentially affected mucin release. The relative effect was correlated with an increase in infection of corneal epithelial cells by P. aeruginosa.


CONCLUSIONS
The results of this study are consistent with the hypothesis that MPCLSs cause increased infections in the cornea by destroying the protective cell-bound mucin layer.
University of Southern California Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, 1975 Zonal Avenue, Los Angeles, CA 90089, USA.
Gabriel M
GM
Gordon
Navid
N
Moradshahi
Shinwu
S
Jeong
Christianne
C
Lane
M Elizabeth
ME
Fini
D015153:Blotting, Western; D018394:CA-125 Antigen / Q000378:metabolism*; D002460:Cell Line; D018639:Contact Lens Solutions / Q000494:pharmacology*; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology*; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D045726:Metalloproteases / Q000235:genetics; D010587:Phagocytosis; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012395:Rose Bengal; D013194:Staining and Labeling / Q000379:methods; D013778:Tetrazolium Salts; D013844:Thiazoles
D018394:CA-125 Antigen; D018639:Contact Lens Solutions; C451759:MUC16 protein, human; D008565:Membrane Proteins; D012333:RNA, Messenger; D013778:Tetrazolium Salts; D013844:Thiazoles; D012395:Rose Bengal; D045726:Metalloproteases; C022616:thiazolyl blue