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Mediators of Inflammation
Volume 2007 (2007), Article ID 93857, 6 pages
http://dx.doi.org/10.1155/2007/93857
Research Article

Secretory Leukocyte Protease Inhibitor Is an Inducible Antimicrobial Peptide Expressed in Staphylococcus aureus Endophthalmitis

1Cornea and External Eye Diseases Lab, School of Medicine, Catholic University of Cordoba, Cordoba 5021, Argentina
2Department of Biochemistry and Molecular Biology, School of Medicine, National University of Cordoba, Cordoba 5022, Argentina
3Cornea and External Diseases, Bascom Palmer, School of Medicine, University of Miami, Miami, FL 33136, USA
4Cornea Department, The Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA

Received 19 June 2007; Accepted 30 October 2007

Copyright © 2007 Victor E. Reviglio et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose. To describe the presence of secretory leukocyte protease inhibitor (SLPI), a cationic peptide with antimicrobial and antiprotease activity, in the innate ocular immune reaction in a rat model of Staphylococcus aureus endophthalmitis. Methods. Seventy-five female Lewis rats were divided into three groups: the endophthalmitis group received an intravitreal injection of 65 colony-forming units of viable S. aureus, the vehicle-injected group received balanced sterile saline solution (BSS), and the control group was not injected. Eyes were enucleated at 24 and 48 hours and processed for immunohistochemical staining and Western blot studies for SLPI. Results. In S. aureus endophthalmitis eyes, there was strong immunostaining for SLPI in the retina and vitreous with associated neutrophilic infiltrates. At 48 hours, corneas also stained for SLPI. Western blots confirmed increased SLPI expression in all infected eyes. By immunohistochemical assays, SLPI was absent in the BSS and control eyes. The causative pathogen was identified in all samples from the endophthalmitis group by traditional culture methods. Conclusions. To our knowledge, this report is the first to demonstrate the presence of SLPI in the inflamed cornea, vitreous, and retina tissues of rat eyes with S. aureus endophthalmitis, suggesting that SLPI has an active role in the innate immunity of the eye. Release of SLPI by inflammatory cells in the anterior and posterior segments may contribute to the host defense response against infectious endophthalmitis.