Another Step Closer to Stopping Ebola Replication

Researchers foresee new, effective Ebola treatments in the future due to a promising discovery in the deadly disease’s replication process.

A collaborative team has filed the protein Niemann-Pick C1 (NPC1) as a key player in the pathogenesis and host infection of the virus. Previous research determined that in vitro Ebola binds to NPC1 in order to enter the host cells; therefore, blocking the interaction proved to inhibit the process. However, little was known about the same method for the in vivo aspect.

“The science behind the concept of blocking the interaction between NPC1 and the virus is solid,” one of the lead authors John Dye, Jr., PhD, from the US Army Medical Research Institute of Infectious Diseases said in a news release.

The team used 3 different types of mice — normal, genetically engineered to completely lack NPC1, and engineered to have both normal and a mutant NPC1 allele – to test the in vivo outcome. The normal mice ended up developing and dying from Ebola within 9 days while those that lacked NPC1 did not show a single trace of the disease. According to study published in mBio, the third group of mice displayed high Ebola viremia levels at first that later decreased and the virus was gone.

“The underlying story of an Ebola infection is that your immune system and the virus are in a race,” Dye explained. “If you can do anything to control the amount of virus that is in the system, keep it below a certain threshold, your immune system in many cases will win that race.”

Although the virus has not become more and less harmful since its first outbreak 40 years ago, the mutation in the RNA of Ebola is just one of the challenges in the way of improved treatments. Furthermore, this identification is especially crucial since a recent case proved that even a clean blood test doesn’t fully clear someone of the deadly disease.

“That research has provided a body of knowledge that scientists could immediately apply to Ebola once it became known that Ebola exploits NPC1 for infection,” author Steven Walkley, DVM, PhD, from Albert Einstein College of Medicine said.

The researchers have already moved on to the next phase of testing by trying 3 NPC1 inhibitors on the mice. Even though one of the drugs did not provide protection and the other 2 only did a little, the pathway to improved treatments is slowly but surely being paved.