Fighting disease with pharming
Scientists grow antibodies in plant cells to combat Ebola and HIV
In the last few decades, scientists have started making drugs in living cells, such as E. coli bacteria and hamster cells, which can be grown in large vats or fermenters. The cells are genetically modified so that they produce the drug molecules – usually proteins, including antibodies against diseases such as breast cancer. Drugs can also be produced in the cells of whole plants – a practice known as pharming.
During the Ebola outbreak in West Africa that started in 2013, limited supplies of the pharmed drug ZMapp were used to treat infected American, British and Spanish patients. The drug consisted of antibodies produced in tobacco plants grown in Kentucky. These plants had been infected with a bacterium carrying genes for making anti-Ebola antibodies and had incorporated these genes into their own plant cells to start making the antibodies themselves. Researchers are now working on pharming anti-HIV antibodies. It’s even thought possible to produce several different medicinal molecules at once to make up the drug cocktails that are required for diseases like HIV. No matter how the drugs are made, however, they still have to undergo rigorous (and expensive) trials in animals and humans before they can be approved for use.
One of the advantages of pharming is that it may be much cheaper to make the drugs required for the early stages of testing.
This approach may be safer too: plants have no risk of transmitting diseases to humans because the antibodies are produced without using the antigen or infectious microorganisms, which is necessary when production takes place in animal cells.Lead image: