Secret serum likely saved Ebola patients (warning: link has auto-play video, ugh)
Three top secret, experimental vials stored at subzero temperatures were flown into Liberia last week in a last-ditch effort to save two American missionary workers who had contracted Ebola, according to a source familiar with details of the treatment.
There was nothing top-secret about the experimental treatment given to the US Ebola patients.
The ‘secret serum’ is just a monoclonal antibody therapy for Ebola. Administering exogenous antibodies as a therapy for viral infections is an old-as-dirt idea.
ZMapp itself is a combination of the ‘best’ antibodies from MB-003 and ZMAb. How do I know this? Because this is information released by the company this July. And MB-003 and ZMAb are not exactly ‘secret’, seeing as they were published in two of the most high profile journals in the world, PNAS and Science.
What I think is super cool is how this therapy is made.
1a. Genetically modify a virus to encode the heavy chain of an anti-Ebola antibody. These antibodies are also genetically modified, btw, to not be as ‘mouse-like’ (they were initially produced in mice) and sometimes to be more ‘human-like’. Putting antibodies from other animals into humans without genetic modification can mean trouble.
1b. Genetically modify a virus to encode the corresponding light chain of the anti-Ebola antibody.
When both of these viruses infect a cell, one viral genome will make half the anti-Ebola antibody, the other viral genome will make the other half of the antibody. Together, the two viruses will make the anti-Ebola antibody!
2a. Put these GMO viral components into a bacteria, Agrobacterium tumefaciens.
2b. Infect a plant, like tobacco, with the Agrobacterium tumefaciens.
You could just infect the plant with the viruses. So why introduce the bacteria into the equation? Because the viruses kinda suck at replicating in the plants. The bacteria helps get the viral genomes to as many parts of the plant as possible, which means lots and lots of cells in the plant are producing antibodies. This bumps up how much antibody you can purify from a single plant by a LOT.
3c. Purify your anti-Ebola antibodies.
Plants are not people. In this case, Nicotiana benthamiana was genetically modified to inhibit the enzymes that make plant sugars plant-like, meaning the anti-Ebola antibodies will have more human-like sugars on the surface. This can be really important for some of the anti-viral properties of the antibodies.
After this genetic modification and infection with the bacteria+viruses, the plant leaves will produce a TON of anti-Ebola antibodies. Plants are a pretty cheap way to produce a lot of protein. Blow up the plant cells, purify your protein, and BAM!
A ton of anti-Ebola antibodies.
Do that with three different anti-Ebola antibodies, mix the antibodies together for an anti-Ebola cocktail, give them to people to see if it helps.
And indeed, if this therapy does prove to play an integral role in ‘saving’ these two US Ebola patients, we probably have a fairly cheap, readily up-scalable and modifiable way to treat the current Ebola epidemic.
GMO viruses + bacteria + GMO tobacco.
Not top secret.
EDIT: Since I drafted this post, CNN changed their headline/article to remove the ‘secret’/’top secret’ references. Stop sensationalizing things, CNN. The science is cool enough as is.