Abstract
Purpose: :
Herpes simplex virus (HSV) is an important cause of keratitis. HSV uses three known classes of receptors for cell entry that are thought to be the key determinants of viral tissue tropism and cell–to–cell spread. These include herpesvirus entry mediator (HVEM, a member of the TNF receptor family), nectin–1 and nectin–2 (members of the immunoglobulin superfamily) and 3–O–sulphated heparan sulphate. The expression pattern of these receptors in the normal and HSV–infected cornea is not well understood. The purpose of this study was to better understand the expression of HVEM in the cornea.
Methods: :
HVEM expression in the cornea of adult healthy BALB/c mice and mice with experimentally induced acute HSV–1 keratitis was determined by immunohistochemistry using a polyclonal rabbit anti–HVEM antibody.
Results: :
Widespread HVEM expression was detected in the corneal epithelium and endothelium of uninfected mice, while the corneal stroma was largely negative for HVEM expression. In HSV–1 infected corneas, the strength of HVEM expression increased in the corneal epithelium and an increased number of HVEM–positive cells, corresponding to inflammatory cells and corneal fibroblasts was detected in the corneal stroma.
Conclusions: :
These findings indicate that HVEM is expressed in the cornea and therefore may serve as an entry receptor for HSV at this site. Furthermore, HSV infection may lead to increased HVEM expression in cornea and this may augment viral pathogenesis.
Keywords: herpes simplex virus • receptors • cornea: stroma and keratocytes