Geek Beat: Locking Out the Ebola Virus
Last week, a team of researchers reported that they had not only discovered a long-elusive biological door through which the Ebola virus invades the human system, but that — with the help of key antibodies from local biotech company Biogen Idec — they could shut that door and lock the virus out.
As viruses go, Ebola is among the more notorious — and most fascinating. Thanks to various dramatic movies like Outbreak and The Hot Zone, most of us have at least a decent sense of what it is — hemorrhagic fever, high mortality rate, lots of blood and, most importantly: a boatload of mystery. Primarily a tropical disease that pops up in central Africa, the virus is also a frequently cited potential bioterrorism tool.
Yet in the 35 years since it first broke onto the scene, we have established only the basics: what it is (an RNA virus), what it does (causes excessive clotting, blockading nutrients from critical organs, and destroying blood vessels), and where it hides out (fruit bats). What we don’t know is the reason for the ebb and flow of outbreaks or how best to treat it or prevent it. And, until last week, we didn’t even how it broke into our system.
That’s what this paper changes. The research team, which stretched as far as NIH and the Universities of Iowa and Texas to our own Cambridge, MA, scanned through reams of human cell lines treated with Ebola virus proteins, to see what genes the cells expressed, and how easily they opened their doors to infection. Out of all the cell lines, one receptor alone stood out: it’s called TIM-1 (short for T-cell immunoglobulin and mucin domain 1), and it’s located on the surface of certain types of cells in our eyes, noses, and throats — coincidentally the primary routes through which the disease is spread. Then, having found their candidate, the researchers pushed it through the hoops by planting it into new cells, knocking it out of others, and checking out how well a TIM-1 selective antibody treatment (by Paul Rennert of Biogen Idec) was able to knock the Ebola virus away from its key point of entry (when administered promptly: 100%).
See, here’s the thing: Yes, this disease has nowhere near the reach of influenza. It’s actually killed fewer than 2,000 people since 1976. But it’s painful, mutilating, deadly when it hits, more active now than ever, and despite the growing number of truly promising vaccines, there is still no licensed treatment.
These findings are no silver bullet: TIM-1 isn’t the only way the virus enters. But this is the first time we have ever identified one of the doors through which the virus can invade. And now that we know that, we can lock the virus out.