Human retinal pigment epithelial cells support replication of Ebola virus and release the virus in high titer, according to researchers who studied live Ebola virus and the ARPE-19 human ocular pigment epithelial cell line.
The study in Translational Vision Science & Technology is the first work to address cellular and molecular mechanisms of Ebola persistence within the human eye, according to researchers.
“We speculate that infected cells activate the type 1 IFN response, which would limit spread of infection, but that these cells also restrict innate and adaptive immune responses, which otherwise would clear the virus from the eye,” researchers wrote.
Infected cells “must mount a robust innate response that overwhelms ocular immune privilege, leading to clinical uveitis,” they continued.
Researchers inoculated ARPE-19 human retinal pigment epithelial cells with Ebola and followed course of infection by immunocytochemistry and measurement of titer in culture supernatant.
They measured infection-induced changes of selected transcripts by reverse transcription-quantitative polymerase chain reaction, according to the study.
Human retinal pigment epithelial cells were permissive to infection with Ebola and supported viral replication and release of virus in high titer, according to researchers.
Researchers found that 28% of 560 upregulated transcripts in Ebola-infected cells were host cell type I interferon (IFN) responsive, indicating a robust type I IFN response. This finding was unexpected, according to researchers.
“The Ebola virus causes severe and accelerated pathology, because it prevents the type I IFN response in other human host cells, including the mononuclear phagocyte populations that are its early targets,” they wrote.
The researchers proposed that the immunomodulatory function of the retinal pigment epithelium is maintained during Ebola infection, which limits immune responses against the virus.
They suggest that the interaction between retinal pigment epithelial cells and Ebola may contribute to a microenvironment that allows live virus to remain inside the human eye. – by Abigail Sutton
The researchers report no relevant financial disclosures.