Glial fibrillary acidic protein expression during HSV-1 infection in mouse cornea

This study aimed to investigate the dynamic expression of glial fibrillary acidic protein (GFAP), a common neural factor, in cornea and stromal cells during herpes simplex virus-1 (HSV-1) infection. For each anesthetized BALB/c mouse, the cornea in one eye was inoculated with 1 × 10(5) plaque forming unit (PFU) of HSV-1, while the contralateral cornea was mock-infected as the control. At different timepoints post-infection, corneal lesion examination by slit-lamp biomicroscopy, corneal histology and HSV-1 DNA detection by real-time PCR were performed to estimate the different stage of HSV-1 infection. The expression of GFAP was examined using real-time PCR, western blotting and immunofluorescence staining. After infected with HSV-1 for 15 days, the mouse corneas began to become clear, the corneal pathology recovered to normal, and HSV-1 DNA almost could not be detected, indicating that HSV-1 was entering a relative quiescent state from the acute infection. The expression of GFAP in HSV-1-infected corneas was comparatively low on day 3, increased slightly on day 7, and further increased thereafter, higher than that in mock-infected corneas on day 15. GFAP detection on the cellular level also indicated that the expression was downregulated in acute HSV-1 infection. GFAP was found to be downregulated in HSV-1 acute infection in cornea and upregulated in late stage, suggesting that GFAP might play some role during HSV-1 infection in cornea.