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Nicotiana benthamiana, already used to produce West Nile virus antibodies, offers similar protection against the devastating Ebola virus

Tobacco Plants Lead the Way to Ebola Cure


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By —— Bio and Archives October 6, 2014

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The already wide horticultural field has expanded yet more to the new science of pharming. This involves the production of pharmaceuticals through the use of genetic engineering to insert genes that code for desired and otherwise expensive and complicated to produce pharmaceuticals into plants.

Today, thanks to the herbaceous plant and close relative of tobacco, Nicotiana benthamiana, already used to produce West Nile virus antibodies, offers similar protection against the devastating Ebola virus. Found amongst rocks on hills and cliffs throughout the northern regions of Australia, it was used by the native peoples as a stimulant prior to the introduction of the more powerful N. rusticana and N. tabacum of North America.

Thanks to its susceptibility to an extensive number of plant viruses and other pathogens, N. benthamiana has become the darling of plant virologists, becoming something of a laboratory workhorse in part due to its fragile foliage. It is particularly popular for studies requiring protein localization, interaction or plant-based systems for protein expression and purification. This explains its sudden fame as a platform for industrial production of recombinant pharmaceutical proteins, including monoclonal antibodies. Scientists at the Boyce Thompson Institute for Plant Research have published a draft sequence.

How is it done? Like many other manoeuvres, the idea is simple, but the execution considerably more complicated. The first step was to inject Ebola virus, Zaire ebolavirus, into mice and extract antibodies. But the human body rejects mice antibodies. The antibody must be refined through another organism dissimilar from Homo sapiens. Previous studies had demonstrated that the solution lay in genetically engineered N. benthamiana to produce a serum. (A review article in the journal Nature explains that a serum gives antibodies directly, rather than waiting two to three weeks after vaccination for the antibodies to work. Serum could be used for treatment whereas a vaccine is likely to be used for protection.)

In this manner, two North American companies created serums. Research by Canadian company Defyrus Inc. resulted in a serum called ZAMb, while San Diego-based Mapp Pharmaceuticals created MB-003. LeafBio, Map Pharmaceutical’s commercial spin-off, combined the two to create ZMapp.

Normally such drugs would face long and arduous clinical testing to assess immune responses and vaccine safety. But the situation in West Africa was deteriorating by the day. It was agreed on compassionate grounds that the limited production of ZMapp would be used on Ebola diagnosed health care workers there. Of the seven treated, two died and five recovered.

According to the Nature review, apart from ZMapp, at least three more serums are in the pipeline and two vaccines. Recent announcements estimate one or more will become available early in 2015. They can’t come soon enough. By the end of January, 2015 it is predicted that there will be a many as 1.4 million infected with Ebola in West Africa with hundreds of thousands of deaths.

Prevention and cure commences with a white-flowered sprawling Australian plant that may reach five feet in height but of which surprisingly little is known botanically.

Wes Porter -- Bio and Archives |

Wes Porter is a horticultural consultant and writer based in Toronto. Wes has over 40 years of experience in both temperate and tropical horticulture from three continents.

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