Animal-free research into hepatitis gets a platform in Nature

In brief:

• Animal-free research into the hepatitis E virus, conducted using human mini-livers with immune cells, has been published in the leading journal Nature Biomedical Engineering.
• This innovative model shows how viruses and the immune system work together to cause damage – something that laboratory animals cannot realistically mimic.
• This means that animal-free methods are finally receiving the scientific recognition they deserve.
• The publication contributes to breaking through the persistent “animal methods bias”: the preference of scientific journals for animal testing.
• This is an important step towards human-centred, animal-free science. Good news for both animals and humans.

It doesn’t happen often enough, but fortunately we are seeing it more and more: animal-free publications in renowned scientific journals. After a wonderful platform for tumour research using mini-intestines, an animal-free model for virus research is now being given a prominent platform in the internationally renowned journal Nature.

Traditionally, the editors of highly coveted international journals such as Nature, Science and Cell have unfortunately preferred animal testing. This is also known as animal methods bias. If we can conclude from these successive publications that old standards are beginning to falter, this would represent a major breakthrough in the transition to animal-free science.

Mini-liver with immune cells makes animal-free virus research more realistic

For the research published in Nature Biomedical Engineering, scientists at Erasmus MC used organoids, a type of cultured mini-organs. These specific mini-organs consisted of human liver cells. The researchers then added immune cells to these cultured mini-livers.

And that is precisely what makes this research so unique. Most organoids contain only cells from the organ that the model is supposed to mimic, but this innovative model also contained immune cells.

The virus and the immune system in focus at the same time

The researchers then infected the mini-livers with the hepatitis E virus. Because the organoids also contain immune cells, they were able to map not only how the virus affects liver cells, but also to study realistically how the human immune system responds to such an infection.

The hepatitis E virus was found to activate the immune cells in the organoids, triggering an inflammatory response. The model thus showed exactly how hepatitis E causes inflammation and damage to the liver. Namely: not only through the virus itself, but also through the response of the immune system.

A big step for animals and humans

Perhaps most importantly, the researchers demonstrated that the model offers many possibilities for testing new treatments for other viruses without the use of laboratory animals. By adding immune cells, they were able to see how they react to infections in combination with liver cells. This applies not only to hepatitis E, but also to other viral infections, such as COVID-19 or mpox.

Traditionally, laboratory animals are often used in research into the effect of viruses on organs. However, the results obtained from animal testing are not always reliable, because animals react differently to viral infections than humans.

This new organoid model with human liver cells and immune cells is much better at predicting how a virus causes damage to human organs than animal testing. This technology allows scientists to study in a very specific and realistic way how viruses make our bodies sick and how our bodies respond to them. This can help in the development of treatments.

Finally recognised at the top of the scientific world

Nature is regarded worldwide as one of the most influential and prestigious scientific journals. The fact that this animal-free research has been published in Nature Biomedical Engineering is therefore good news that extends beyond this particular study.

Research published in such a journal undergoes a rigorous selection process with extensive peer reviews. This makes a publication a mark of quality. The fact that this mark of quality has now been awarded to an animal-free innovation is extremely important. It shows that animal-free research is not only ethically desirable, but can also be scientifically leading.

The animal methods bias is persistent, but not insurmountable

Unfortunately, this recognition is not yet self-evident. There is a deep-rooted preference for animal testing in science: the so-called animal methods bias. Journals and funding bodies often still regard animal testing as the gold standard. This forces researchers to conduct animal testing, even when there are good alternatives that do not involve animals.

For example, this 2023 study showed that a third of the scientists surveyed had conducted animal testing purely to meet the requirements of journal editors. This not only hinders the development of animal-free innovations, but also impedes the careers of young researchers who want to innovate.

Small cracks in the vicious circle

The animal methods bias creates a vicious circle: those who conduct animal testing find it easier to publish and obtain funding more quickly. As a result, animal testing remains the norm, while animal-free alternatives are given fewer opportunities. This leads to unnecessary animal suffering and slows down the transition to human-centred science without animal testing.

If renowned journals and funding bodies give more space to animal-free innovators, the transition to animal-free, human-centred science will accelerate. The fact that there are more and more animal-free publications shows that cracks are beginning to appear in the vicious circle – and that is good news for the transition to animal-free science.

Are you a scientist or student who encounters animal methods bias when you want to publish or are looking for research funding? Please contact us, we will help you with strategy, arguments and examples to further your animal-free research.