PURPOSE: The present study was aimed to investigate whether herpes simplex virus type 1 (HSV-1) could infect human retinal pigment epithelial (RPE) cells in vitro and the effects of HSV-1 on the growth of human RPE cells. METHODS: RPE cell line D407 was infected with HSV-1 F strain at a multiplicity of infection of 5. The susceptibility to HSV-1 was assessed by the detection of viral DNA using the polymerase chain reaction (PCR), and viral antigen using immunofluorescence staining. At indicated times, contrast-phase microscope was used to record the morphological changes of HSV-1 infection of RPE cells. Cell proliferation was measured by MTT assay. Cell apoptosis and cell cycle were detected by flow cytometry. RESULTS: HSV-1 infected RPE cells successfully in vitro. The contrast-phase microscope revealed that cytopathic effects (CPE) were first observed at 8 h post-infection. The infected cells became slender and shrinking. At 24 h post-infection, nearly all the cells displayed CPE changes. Occasionally multinucleated giant cells were found. At 48 h, the infected cells became round, some even detached from the culture flask. Cell proliferation were dramatically inhibited by HSV-1 at 24 h and 48 h post-infection, and the inhibition ratio were (16.37 +/- 3.28)% and (47. 91 +/- 6.39)% respectively. Furthermore, HSV-1 could perturb the cell cycle in the infected cells, and had no effect on cell apoptosis. CONCLUSIONS: Our data suggested that RPE cells are susceptible to HSV-1. HSV-1 can inhibit cell proliferation and perturb the cell cycle in the infected cells.
PURPOSE: The present study was aimed to investigate whether herpes simplex virus type 1 (HSV-1) could infect human retinal pigment epithelial (RPE) cells in vitro and the effects of HSV-1 on the growth of human RPE cells. METHODS: RPE cell line D407 was infected with HSV-1 F strain at a multiplicity of infection of 5. The susceptibility to HSV-1 was assessed by the detection of viral DNA using the polymerase chain reaction (PCR), and viral antigen using immunofluorescence staining. At indicated times, contrast-phase microscope was used to record the morphological changes of HSV-1 infection of RPE cells. Cell proliferation was measured by MTT assay. Cell apoptosis and cell cycle were detected by flow cytometry. RESULTS:HSV-1 infected RPE cells successfully in vitro. The contrast-phase microscope revealed that cytopathic effects (CPE) were first observed at 8 h post-infection. The infected cells became slender and shrinking. At 24 h post-infection, nearly all the cells displayed CPE changes. Occasionally multinucleated giant cells were found. At 48 h, the infected cells became round, some even detached from the culture flask. Cell proliferation were dramatically inhibited by HSV-1 at 24 h and 48 h post-infection, and the inhibition ratio were (16.37 +/- 3.28)% and (47. 91 +/- 6.39)% respectively. Furthermore, HSV-1 could perturb the cell cycle in the infected cells, and had no effect on cell apoptosis. CONCLUSIONS: Our data suggested that RPE cells are susceptible to HSV-1. HSV-1 can inhibit cell proliferation and perturb the cell cycle in the infected cells.