Antibodies from ebola survivor are being cloned to develop new drug (Dutch below)

Antibodies derived from an ebola survivor to cure seriously-ill patients. This is what US Dr James Crow, from the Vanderbildt University tries to achieve together with pharmaceutical company Mapp. This is the producer of the experimental ebola drug  ZMapp, consisting of a cocktail of three antibodies originating from mice. Human  derived antibodies could be better in beating the virus

From DNA to antibody

Dr. Rick Sacra, an US physician who contracted the virus while working in Liberia, donated blood. The scientists are searching after his antibody-producing white blood cells, the B-cells. James Crow selects the cells that produce antibodies to ebola and clones the genes encoding those antibodies  The DNA supplies the researchers with an endless source for antibody production. It can be stored for ages and multiplied in bacteria, a rather simple step. To go from DNA to antibody Mapp receives help from the Amgen company. Mapp, who produce their own antibodies in tobacco plants, will make large quantities of the human antibodies in mammalian cells. To do so, the antibody-DNA is  transferred into those cells, which read the code and translate that to large amounts of antibodies. This takes place in bioreactors. What follows is a long way of testing. Are these antibodies capable of neutralizing ebola? This is first tested in the lab, later in animals. The new drug is clearly not ready-to-use tomorrow.

Cloning antibodies from patients is a well-known method. But why should you clone them, why not purify them directly from the blood? That is because large volumes of patient blood are needed to purify sufficient amounts of antibodies. During the height of the epidemic many patients have high titers of anti-ebola antibodies. But when the disease fades out, the titers drop. Complicating factor is that many patients are infected with other viruses or parasites, like HIV. You don’t want that in your medication vial.

Purified from blood

Nevertheless, this is frequently done. Think of tetanus. For this disease in the Netherlands volunteer donors are frequently vaccinated to maintain high titers. The antibodies are purified from their blood to cure patients who have contacted this serious disease. The same goes for anti-rhesus-D injections. Antibodies to rhesus D are purified from blood of women who in the past had made antibodies to their babies. Next, patients with immune deficiencies receive antibodies purified from plasma of thousands of blood bank donors. They get the entire spectrum, so to defeat all general occurring infections.

The question remains whether Sacra survived thanks to his effective antibodies or whether the supporting treatment in an US hospital was crucial.

Source: http://www.reuters.com/article/2014/12/22/us-health-ebola-usa-antibodies-exclusive-idUSKBN0K00VA20141222