Research led by a team from the University of California, Los Angeles (UCLA) has identified a protein with broad virus-fighting properties that potentially could be used as a weapon against deadly human pathogenic viruses such as HIV, Ebola, Rift Valley Fever, and others designated biological threat agents of concern.
The novel antiviral properties were found in cholesterol-25-hydroxylase (CH25H), an enzyme that converts cholesterol to an oxysterol called 25-hydroxycholesterol (25HC), which can permeate a cell’s wall and block a virus from getting in.
Interestingly, the CH25H enzyme is activated by interferon, an essential antiviral cell-signaling protein produced in the body. “Antiviral genes have been hard to apply for therapeutic purposes because it is difficult to express genes in cells,” said lead author Su-Yang Liu. “CH25H, however, produces a natural, soluble oxysterol that can be synthesized and administered.”
The researchers initially found that 25HC dramatically inhibited HIV in cell cultures. Next, they administered 25HC in mice implanted with human tissues and found that it significantly reduced their HIV load within seven days. The 25HC also reversed the T-cell depletion caused by HIV.
By contrast, mice that had the CH25H gene knocked out were more susceptible to a mouse gammaherpes virus, the researchers found.
In collaboration with Dr. Benhur Lee, a professor of pathology and laboratory medicine and a member of the UCLA AIDS Institute, they discovered that 25HC inhibited HIV entry into the cell. Furthermore, in cell cultures, it was found to inhibit the growth of other deadly viruses, such as Ebola, Nipah and the Rift Valley Fever virus.
The discovery is particularly relevant to efforts to develop broad-spectrum antivirals against an increasing number of emerging viral pathogens, Liu said.
Read the rest of the story at the UCLA Newsroom: Newly identified natural protein blocks HIV, other deadly viruses