Ebola virus (green) on a cell surface. Credit: National Institutes of Allergy and Infectious Diseases, NIH

Australian researchers have found retinal pigment epithelial (RPE) cells appear to be particularly susceptible to harbouring Ebola and other viruses. 

Uveitis occurs in up to one-third of Ebola survivors and we know iris and retinal cells can host microorganisms, said study senior author Professor Justine Smith from Flinders University. “However, what we didn’t know was which out of the two was most responsible in the case of Ebola,” she said. 

Researchers at the Commonwealth Scientific and Industrial Research Organisation’s Australian Centre for Disease Preparedness infected human eyes donated from the South Australia Eye Bank with Ebola virus, Reston virus (a type of ebolavirus that does not cause disease in humans) or Zika virus. While Ebola replicated in the iris and retinal cells, much higher levels of infection were seen in the former, a pattern followed by all three viruses, said Prof Smith. 

Patients with Ebola eye disease have characteristic retinal scars, suggesting the RPE is involved in the disease, which is consistent with what eye doctors are seeing in the clinic, said Prof Smith. “These retinal cells are good at phagocytosis and play an essential part in the visual cycle by recycling our photoreceptors, so it makes sense that they would be a receptive haven for Ebola and other viruses,” she said. 

Researchers said the study suggests the potential for the RPE to be monitored during acute viral infection to identify patients at highest risk of uveitis.