By Clare Wilson
Snake milking can get messy
Kirill Kukhmar/TASS via Getty Images
Snake glands have for the first time been grown in the lab as tiny balls of cells called organoids that become filled with venom. It might mean the end of “milking” snakes for their venom venom by hand to produce treatments for bites.
As well as becoming a new source of venom for the makers of snakebite antidotes, the clumps of cells, just 1 millimetre across, could also be used for turning the biochemicals in snake venom into medicines, because they have powerful effects on the body, says Hans Clevers of Utrecht University in the Netherlands.
His team created the venom organoids by taking tiny clumps of gland tissue either from snake embryos inside eggs or in one case from a pet snake that had to be put down due to illness.
Antivenom is currently made by keeping snakes in captivity and extracting their venom. This is injected in low doses into horses, which make antibodies that can be taken from their blood. This is not a 21st- century drug, this is a 19th-century drug, says Clevers.
Being able to make venom in the lab would cut out the snake farming part of the process. It is labour intensive, so only a few kinds of snakes are kept in this way, but there are an estimated 600 species that are venomous, meaning we don’t have antidotes for many snake bites.
In the longer term, antibodies to lab-produced venom could be made by immune cells grown in a dish, avoiding all use of animals.
The snake gland organoids could also be a source of new medicines. Several existing drugs are based on compounds found in snake venom, such as a major class of drugs that lower blood pressure, based on a toxin made by the Brazilian pit viper.
Any one species venom typically has more than 20 compounds that have biological effects. They may work by affecting the heart, the nervous system or paralysing muscles, for instance. We plan to build a large biobank of different species venom glands for bioprospecting, says Clevers.
Journal reference: Cell, DOI: 10.1016/j.cell.2019.11.038
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By Clare Wilson