Researchers develop lab-produced antivenom offering broad protection from diverse Indian cobras

Researchers have developed a recombinant antivenom that has shown broad protection in mice against the venom of spectacled cobras monocled cobras and both Indian king cobra speciesA recombinant antivenom is labproduced It uses biotechnology and is designed to replace traditional animalderived antivenomsThe team from the Indian Institute of Science IISc and Germanys Technical University of Denmark said that unlike conventional antivenoms recombinant antibodies can be manufactured using microbial and humanised expression systems without repeatedly immunising animals such as horsesConventionally snake venom is injected into a horse or sheep which produces antibodies in response The antibodies are used in making an antivenom considered the only solution to treat a snake biteAntivenom treatment has virtually not changed for over 100 years This is the only nextgeneration antivenom we have now which could tackle Indias snakebite problem author Kartik Sunagar associate professor at the centre for ecological sciences IISc saidEach snake species produces a distinct cocktail of toxins that attack nerves blood or tissues making it difficult to develop a unified treatment the researchers saidCurrent animalderived antivenoms also have drawbacks such as batchtobatch variability side effects and limited species coverage they said adding that their production is costly and outdated relying on venom milking and animal immunisation with low yields of active antibodiesIn the study the team used camelid antibodies which they developed in a previous study where camelids including alpacas and llamas were immunised with venom from African snake species Antibodies generated in response were extractedThe researchers exposed the camelid antibodies to venom from different cobra species in India and found that toxins produced by Indian snakes too could be neutralisedThis work provides a blueprint for how recombinant antivenoms can be tailored to different regions of the world by targeting the toxin families that drive disease in local snake species author Andreas Laustsen professor at the Technical University of Denmark saidThe researchers explained that antibodies are usually Yshaped with both heavy and lightchain proteins They used a portion at the tip of the Y shape made up of lightchain proteins that can specifically bind to the venom toxinsThe team isolated a cocktail of five such antibody fragments called nanobodies that could bind to toxins in the various cobra species they testedThey found that the cocktail could neutralise venom activity and prevented the venom from binding to its target receptorTesting the antibody cocktail in mice injected with venom the researchers found that the animals were protected against toxins from spectacled cobras monocled cobras and both Indian king cobra speciesMice were saved from death even 30 minutes after venom injectionEven mice that were paralysed or had typical neurotoxic symptoms would revert to a completely asymptomatic state Sunagar saidThese findings demonstrate the feasibility of developing broadspectrum nanobodybased recombinant antivenoms with continentwide coverage as a safe and regionally adaptable biologic for snakebite envenoming therapy the authors wrote