Accelerating the replacement of animal-derived antibodies

Our CTO, David Bunka, presented and participated in a workshop run by the National Centre for the Replacement, Refinement & Reduction of Animals in Research (NC3Rs), entitled ‘Accelerating the replacement of animal-derived antibodies.’ This workshop brings together key industry and academic figures from the life science community to address the need to move away from animal-derived affinity reagents and develop a strategy to support the wider adoption of non-animal-derived affinity reagents.??

Antibodies have been used as crucial tools for research, diagnostics, therapeutics, and regulatory procedures. Traditionally developed using large numbers of animals, antibody utility is the subject of much debate due to issues of specificity and reproducibility. However, recombinant technologies have become available in the last two decades to generate animal-free antibodies and affinity reagents, such as aptamers and other protein scaffold technologies. These animal-free affinity reagents offer equivalent or improved target binding to animal-derived antibodies.??

Non-animal-derived alternatives, such as aptamers, offer many scientific, economic, and animal welfare advantages over traditionally derived products.?

Better science?

The reproducibility crisis has highlighted that many life science experiments cannot be replicated and that the conclusions based on these studies may be unfounded, with antibodies identified as an essential part of the problem.1-7 Across biomedical research, global annual losses from using poorly characterized antibodies have been estimated at $800 million, not counting wasted research time and resources, as well as the impact of false conclusions.4?

With the move to non-animal-derived affinity reagents, the quality of science and its resulting impact on society will improve because these reagents have demonstrated high specificity, a significantly expanded range of applications, and are routinely sequenced, thus allowing fast and reliable identification and reproduction.?

Additionally, developing non-animal-derived affinity reagents allows researchers to pursue new targets, such as toxins, venoms, and low immunogenic molecules, that would not be possible when relying on the animal’s immune system to generate an antibody reagent. With toxins, the animal would die before raising an immune response and the consequent antibodies, while low immunogenic molecules will not raise sufficient immune response to generate antibodies.???

Better costs?

While establishing libraries for non-animal-derived affinity reagents requires skilled molecular biology expertise and substantial time investment, the diversity and longevity of such libraries after construction and the abolition of ongoing animal care costs make this effort worthwhile. Following the development of such libraries, animal-derived antibody generation and validation costs are in the same range as those of non-animal-derived alternatives.8?

Furthermore, due to the small size of aptamers compared to large antibody molecules, mole for mole there is an increased amount of aptamer available per gram. This can give rise to reduced assay costs for aptamers compared to antibodies or the option to increase assay signal through the use of more aptamer than antibody at a highly competitive price.??

Besides cost, there is a significant benefit in time as aptamers and other non-animal-derived affinity reagents can be selected in a matter of weeks, as impressively demonstrated by the development of SARS-CoV-2 reagents by Aptamer Group in just 17 days during the pandemic.9???

Better ethics?

In Europe alone, estimates suggest that about one million animals are used each year in antibody generation.10 The move from traditional antibodies to proven technologies such as aptamers and protein scaffold alternatives could significantly reduce this unnecessary animal usage across the industry. Even recombinant antibodies are initially generated in animals, such as rabbits or rodents, whereas using protein scaffolds or nucleic acid aptamers generated through diverse in vitro libraries offers further reductions.

From blue sky researchers to large pharma partners, we are seeing a shift towards pursuing aptamers as non-animal-derived affinity ligands to support research and development needs. Using non-animal-derived affinity technologies as a starting point for new reagent generation over antibodies, raising awareness that alternative proven solutions are available and??

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1. Bordeaux, J. et al. Antibody validation. Biotechniques 48 197-209 (2010).?
2. Egelhofer, T.A. et al. An assessment of histone-modification antibody quality. Nature Struct. Mol. Biol. 18, 91-93 (2011).?
3. Baker, M. Reproducibility crisis: Blame it on the antibodies. Nature. 521, 274-276 (2015).?
4. Bradbury, A. & Plückthun, A. Reproducibility: Standardize antibodies in research. Nature. 518, 27-29 (2015).?
5. Baker, M. 1,500 scientist lift the lid on reproducibility. Nature. 533, 452-454 (2016).?
6. Begley, C.G. & Ellis, L.M. Raise standards for preclinical cancer research. Nature. 483, 531-533 (2012).?
7. Baker, M. Antibody anarchy: A call to order. Nature. 527, 545–551 (2015).?
8. Gray, A. Animal-free alternatives and the antibody iceberg. Nat. Biotech. 38, 1234–1239 (2020).?
9. Aptamer Group. Rapid identification and development of SARS-CoV-2 selective Optimers?. Accessed at: https://mailchi.mp/aptamergroup.co.uk/vjsag100vn (2020)?
10. Gray, A. C. Animal-derived-antibody generation faces strict reform in accordance with European Union policy on animal use. Nat Methods 17, 755–756 (2020).?