Healing honey

2019-03-08 05:11:02

By Andy Coghlan A SPOONFUL of honey could help the medicine go down, say Dutch biologists. They are genetically engineering plants so that honey made from their nectar will contain drugs or vaccines. The honey could either be fed directly to patients, or drugs could be extracted from it. “It’s a production system that would require very little purification,” says Tineke Creemers of the Centre for Plant Breeding and Reproduction Research in Wageningen. “The protein is concentrated by the bees, so it’s a very cheap production method.” The researchers also hope that the sugars in honey will act as a preservative, and are investigating whether proteins in honey retain their activity even if it is not refrigerated. If so, this would be a boon for vaccination programmes in poor tropical countries, which are often hampered by shortages of cooling equipment. Two discoveries came together to spawn the project. First, to their surprise, Creemers and her colleagues discovered antifungal proteins in nectar from common heather, Caluna vulgaris. They wondered if bees pass the proteins undigested into honey—and tests of commercial brands showed that they do. The researchers also fed bees a sugar solution laced with a protein called bovine serum albumin. “The proteins remained intact in the honey and were concentrated twofold compared with the original solution,” says Creemers. Secondly, she and her colleagues discovered a genetic switch, or promoter, which activates genes in the nectary, the organ in plants where nectar is made. So they decided to try to add genes for various drugs to plants in such a way that the genes would be activated by the nectary promoter. Because the promoter is specific to the nectary, these drugs should be produced only in the nectar, where bees could eat them. They are in the process of genetically engineering petunias so that they produce a vaccine against a disease of dogs caused by a parvovirus. The active component is part of a surface protein made by the virus, which should trigger immunity in dogs. “The dogs would either eat the honey as an oral vaccine, or the vaccine would be purified and injected,” says Creemers. Once the plants are fully grown and begin producing nectar, bees will be unleashed on them to produce honey that the researchers hope will contain the vaccine. Creemers and her colleagues expect to harvest the first honey in a year’s time. “It’s an exciting variation on making vaccines in plants,” says Charlie Arntzen of Cornell University in Ithaca, New York, who is producing bananas engineered to contain vaccines. Creemers and her colleagues are doing their experiments in glasshouses, to ensure that their bees feed only on the modified plants and to minimise concerns of the vaccine genes being spread by pollen. Because of this they are using bumblebees,