Roles of TRIM32 in Corneal Epithelial Cells After Infection with Herpes Simplex Virus.

Epithelial cells play important roles as a critical barrier in protecting the cornea from microbial pathogens infection. In this study, we were aiming to investigate the role of E3 ubiquitin ligase tripartite motif protein 32 (TRIM32) in corneal epithelial cells in response to Herpes Simplex Virus type 1 (HSV-1) infection and to elucidate the underlying mechanisms. We found the expression of TRIM32 was increased after infected with HSV-1 both in murine corneas and cultured human epithelial (HCE) cells. Furthermore, knockdown of the expression of TRIM32 significantly aggravated HSV-1 induced herpetic stromal keratitis (HSK) in mice and promoted the replication of HSV-1 in cultured HCE cells. We also observed that silencing of TRIM32 resulted in the decreased expression of IFN-β and suppressed activation of interferon regulatory factor 3 (IRF3) both in vivo and in vitro. Finally, we found TRIM32 positively regulate IFN-β production in corneal epithelial cells through promoting K63-linked polyubiquitination of stimulator of interferon genes (STING). In conclusion, our data suggested that TRIM32 as a crucial positive regulator of HSV-1 induced IFN-β production in corneal epithelial cells, and it played a predominant role in clearing HSV-1 from the cornea.