Role of host-defence peptides in eye diseases

Abstract

The eye and its associated tissues including the lacrimal system and lids have evolved several defence mechanisms to prevent microbial invasion. Included among this armory are several host-defence peptides. These multifunctional molecules are being studied not only for their endogenous antimicrobial properties but also for their potential therapeutic effects. Here the current knowledge of host-defence peptide expression in the eye will be summarised. The role of these peptides in eye disease will be discussed with the primary focus being on infectious keratitis, inflammatory conditions including dry eye and wound healing. Finally the potential of using host-defence peptides and their mimetics/derivatives for the treatment and prevention of eye diseases is addressed.

Fig. 1

Expression profile of host-defence peptides in the eye. The diagram summarises the pattern of expression of the major HDPs in the human eye. These data are derived primarily from studies to detect peptide expression that have been performed on cultured cells in vitro and on tissue/tear fluid samples from human donors (these studies are summarised and references given in the section “Expression and distribution of host-defence peptides in the eye and associated structures”). Lacrimal gland and lacrimal drainage are not included but are discussed in the section “Associated ocular structures”