Glycoprotein C of herpes simplex virus type 1 is required to cause keratitis at low infectious doses in intact rabbit corneas.
OBJECTIVE
To determine whether the herpes simplex virus type 1 (HSV-1) viral glycoprotein C (gC) plays a role in induction of keratitis in unscarified and scarified rabbit eyes.


METHODS
A gC deletion mutant (DeltagC) was constructed and then rescued back to wild type (wt) for use as a control. Following ocular infection with each virus in rabbit eyes, with or without prior corneal scarification, keratitis was compared.


RESULTS
At low infection doses of 2 x 10(3) and 2 x 10(4) plaque-forming units (PFU)/eye, in unscarified cornea, DeltagC produced significantly less keratitis than did wt virus (p = 0.007 and 0.03, respectively). In contrast, the keratitis induced by DeltagC was similar to that induced by the wt virus (p > 0.60) in scarified cornea. At high infection dose (2 x 10(5) PFU/eye), keratitis induced by DeltagC was similar in scarified and unscarified cornea, and the severity of disease was similar to that seen in scarified eyes at the low-dose DeltagC infections. Interestingly, although DeltagC induced keratitis with or without corneal scarification at high infection doses, the severity of disease was significantly less than that induced by wt infection. At all infection doses, keratitis induced by wt infection was similar in scarified and unscarified eyes.


CONCLUSIONS
These results suggest that (1) at low infection doses, in unscarified corneas, gC is required for HSV-1 induced keratitis; (2) corneal scarification prior to infection can circumvent the need for gC at low doses, but (3) at higher doses, gC is required for wild-type levels of keratitis even in scarified cornea.
Drolet
Barbra S
BS
Department of Ophthalmology, UC Irvine College of Medicine, Irvine, CA, USA.
Mott
Kevin R
KR
Lippa
Andrew M
AM
Wechsler
Steven L
SL
Perng
Guey-Chuen
GC
D000818:Animals; D002460:Cell Line; D002921:Cicatrix / Q000821:virology; D003315:Cornea / Q000378:metabolism* / Q000821:virology*; D003316:Corneal Diseases / Q000821:virology; D005123:Eye / Q000821:virology; D017353:Gene Deletion; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000472:pathogenicity*; D016849:Keratitis, Herpetic / Q000209:etiology* / Q000821:virology*; D008297:Male; D009154:Mutation; D011817:Rabbits; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D014759:Viral Envelope Proteins; C038535:glycoprotein gC, herpes simplex virus type 1