Abstract
Purpose :
Staphylococcus aureus (S. aureus) and Herpes simplex virus type-1 (HSV1) are common pathogens of ocular surface infection. Their interaction is poorly understood. This study aimed to investigate the effect of S. aureus lysates (SAL) on the HSV1 infection in Human Corneal Epithelial cells-Transformed (HCE-T) and employ RNA sequencing (RNA-seq) to explore the transcriptomic responses of HSV1-infected HCE-T with SAL treatment.
Methods :
Two strains of HSV1, HSV1 F strain (HSV1f) and HSV-1 strain-H129 knocked in GFP (HSVg4) at MOI 0.1 and 1, were used to infect HCE-T. Pre- or post-virus-infection, SAL at various protein concentration were added into serum-free medium and cultured up to 24 hours. GFP fluorescence of HSVg4 in cells was examined under a fluorescence microscope and photographed. The expression of viral ICP4 protein of HSV1f was assayed by immunofluorescence and Western blot assay. Plaque sizes were used to evaluate HSV-1 replication. Next, RNA-seq was performed on BGISEQ-500RS production system.
Results :
Similar changes but at different degrees were found in cells that were infected with MOI 0.1 and MOI 1.0 HSV-1. With the increasing of SAL concentration in culture media, the morphological results showed that cell lesions decreased. The GFP fluorescence of HSVg4 and ICP4 staining of HSV1f decreased in a dose-dependent manner. Plague assay showed that treatment with SAL decreased the plaque sizes and numbers. The transcriptome data show that treated SAL cells which were infected with HSV1 lead to 251 genes increased and 169 genes decreased. SAL can increase the expression of anti-oxidative genes (SOD2, GCLM and HO-1), anti-apoptosis genes （IAP and Bcl2）, OASL related genes (negative regulative of viral replication), ADAM8 related genes (activation of MAPK activity involved in innate immune response).
Conclusions :
Our study suggests that SAL inhibits HSV-1 infection in the HCE-T. SAL may protect HCE-T from HSV-1 infection by increasing anti-oxidative, anti-viral replication and anti-apoptosis. However, the active component of S. aureus remains to be identified.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.