Scientists have discovered that the protein NPC1 may play a key role in preventing Ebola infections, or at least decreasing their severity. NPC1 is a protein that is found in the endosome and brings cholesterol into the cytoplasm. Individuals who lack NPC1 have Niemann-Pick disease, where cholesterol builds up in the brain, liver, and spleen. When cells from individuals with Niemann-Pick were infected with an experimental Ebola-ike virus, they were much better able to fight off infection than cells with normal levels of NCP1. This is because without functional NPC1, the virus can't enter the cytoplasm, and no infection can occur.
Researchers are now working on finding small compounds that block the interaction of NPC1 and viruses related to Ebola. So far several articles have been published in Nature, and the antidepressant imipramine has been found to block NPC1. While NPC1 trials have worked on Marburg-infected mice and cells, no trials with imipramine or other NPC1 blockers have been undertaken yet. However, these preliminary results are exciting: to think, that the key to fighting Ebola might be an antidepressant that's already on the market.