The spectrum of expression of anti–microbial peptides at the Ocular surface

Abstract

Abstract: : Purpose: The beta defensins are highly conserved cationic anti–microbial peptides. We have previously shown that beta defensin 1 (hBD1) and hBD2 are made by various ocular epithelial cells. In addition to their anti–microbial activity, these peptides can signal to host cells via the chemokine receptor CCR6, and may be a crucial intermediary between the innate and adaptive immune responses. Our purpose was to fully characterise expression of anti–microbial peptides, including all members of the beta defensin family, at the surface of the human eye. Methods: Total RNA was obtained from corneal and conjunctival material, both fresh (by impession cytology) and from cultured epithelial cells. The expression of 20 anti–microbial peptides was determined usting RT–PCR and quantitated using real–time PCR. Results: Five anti–microbial human beta defensins (hBD1–3), liver expressed anti–microbial peptide 1(LEAP1) and LL37 were detected in most or all epithelial samples. A further three anti–microbials (hBD4, LEAP2 and dermicidin) were detected in some samples. Expression was confirmed and quantitated using real–time PCR, allowing quantative sample to sample comparison of expression. Conclusions: We have detected teh expression of at least five anti–microbial peptides at the surface of the eye, This has significant implications both for the normal homeostasis of the eye and for future pharmacologiacl anti–microbial and anti–inflammatory therapies.

Keywords: cornea: basic science • conjunctiva • antibiotics/antifungals/antiparasitics