Abstract
Purpose: :
To evaluate trends in HSV-1 infection of organotypically cultured corneal tissue and determine a possible correlation to the expression of heparan sulfate (HS).
Methods: :
Organotypically cultured corneas obtained from donated pig eyes were infected with purified HSV-1 K26GFP without corneal scarification. These sections were fixed at various time points up to 72 hours and compared with non-infected controls by immunohistochemistry. Sections fixed after 12 hours of infection were stained for HS using an antibody against the 10e4 epitope and compared to non-infected controls. Sections from the same time points were also stained for syndecan-1, a HS proteoglycan. Flow cytometry was performed on HeLa cells, which are known to express HS, using antibody against the 10e4 epitope. Heparan sulfate expression was determined at various time points of infection with HSV-1 (KOS strain) and compared to non-infected controls.
Results: :
Corneal epithelial infection with HSV-1 was confirmed by immunohistochemistry, which demonstrated increased viral antigen expression over time, although infection remained focal at 72 hours. There was positive staining in the epithelium of non-infected corneal sections for HS and syndecan-1, with some accentuation near the basal surface. After 12 hours of infection, an increase in HS expression was noted in the epithelium. Similarly, syndecan-1 expression in the epithelium increased after infection, although the rise was more dramatic. Flow cytometry using HeLa cells demonstrated an increase in HS expression after infection up to 6 hours.
Conclusions: :
HSV-1 is able to infect non-scarified organotypically cultured corneal tissue and correlates with a rise in heparan sulfate expression in corneal tissue and cultured cells. This also demonstrates for the first time a possible role for syndecan in ocular herpes infection.
Keywords: herpes simplex virus • immunohistochemistry • proteoglycans/glycosaminoglycans