Lipopolysaccharide enhances HSV-1 replication and inflammatory factor release in the ARPE-19 cells

During acute retinal necrosis (ARN), retinal pigment epithelial (RPE) cells could be stimulated by both herpes simplex virus (HSV) and lipopolysaccharide (LPS). We aim to investigate the impact of LPS on HSV-1 infection and inflammatory factors in human retinal pigment epithelial cell lines (ARPE-19 cells).

ARPE-19 cells were infected by HSV-1F strain and HSVg4 strain, a modified HSV strain with GFP genes cloned in, for 1 h. Different concentrations of LPS were added. Green fluorescence protein (GFP) of HSVg4 and the infected cell protein 4 (ICP4) expression were observed. Cell culture supernatants were collected to detect 34 kinds of related cytokines and chemokines by multiplex immunoassay assay.

Under LPS treatment, the cytopathic effect displayed as enlarged multinucleated cells, and the GFP fluorescence intensity and ICP4 expression increased in the HSV-1-infected ARPE-19 cells. HSV-1 infection stimulated cytokines IL-1α, IL-1β, IL-1RA, IL-2, IL-4, IL-6, IL-9, IL-12P70, IL-15, IL-18, IL-21, IL-27, TNF-α, IFN-γ and chemokines CXCL1, CXCL8, CXCL10, CXCL12, CCL2, CCL3, CCL4, CCL5, CCL11 while LPS further enhanced their expression.

LPS promoted HSV-1 infection and inflammatory factor release in ARPE-19 cells, indicating that ARN could deteriorate when complicated with endotoxemia.