A small Catalan Noah's Ark of laboratory-made mini-organs

The nightmare had only just begun. Two months after the first cases were reported After what appeared to be a new type of pneumonia in Wuhan, China, Julia Vergara and Karl Kochanowski, like so many other scientists around the world, began to research against the clock this new pathogen that threatened humanity. They were familiar with some coronaviruses, because years ago in the Animal Health Research Center (CReSA-IRTA) They had studied some that affect animals. And this, fortunately, allowed them to know some of the tricks of SARS-CoV-2.

But far from all of them. Which species did this new strain affect? Which ones could be reservoirs? Only wild ones, or could it also jump between livestock? At that time, news reports were coming out that pointed to pangolins and bats. But cases of contagion were also detected in big cats in zoos and on mink farms, and the population was beginning to worry about their pets. They remember the Negrito, The first documented cat infected with SARS-CoV-2 in Spain?

To be able to answer all those questions, studies were needed that involved taking individuals, exposing them to the pathogen and seeing what happened. A huge investment of resources. And although they began experimenting with mice, every time a new variant emerged, they had to start from scratch.

It was then that the two researchers from the Animal Health program at IRTA-CReSA, Vergara and Kochanowski, thought about the organoids, small replicas of organs These are made in the laboratory from stem cells obtained from animal samples. Or from humans, because they are also increasingly used in human health research. Although they are not a 100% exact copy, they recreate much of the complexity of tissues. Therefore, Kochanowski believes, "they offered us a good option." in vitro to replace animal experiments."

Unique in Europe

From IRTA-CReSA, located on the Autonomous University of Barcelona campus, they began working with the goal of creating a biobank made up of these mini-replicas of organs from different species that would allow them to carry out all kinds of experiments quickly and without needing to use any real animals. Two years later, in 2023, it became a reality: they had created a pioneering biobank of animal organoids. To do so, they obtained three-year funding from the Spanish government and involved IrsiCaixa, the Barcelona Supercomputing Center (BSC-CNS), and a pharmaceutical company, Pharmamar.

"It's a strategic complementary project," says Natàlia Majó, head of the Animal Health program at IRTA-CReSA, who assures that "there is no other biobank in Europe [or the world] with these characteristics, with the large number of organoids we have, nor with the diversity of species that there already is." And they have everything from zebras to chickens, cows, and iguanas.

The mini-organs they've created are from the digestive and respiratory systems of more than 20 species, mostly mammals, although they also have birds and some reptiles, and from around 140 individuals. They have the most pigs and livestock species; they have cohorts: samples of specimens of different ages and sexes to be able to evaluate the individual response to an infection, a drug, or a nutritional compound, for example.

"We're focusing on the respiratory and digestive systems because they're the two main entry points for pathogens into the body," explains Gerardo Ceada, head of the IRTA-CReSA organoid biobank, from Kenya. As the Wi-Fi connection has dropped, after a while he gives up trying to connect from his computer and opts to conduct the interview with ARA from his mobile phone.

Ceada arrived in this East African country just a few weeks ago, where he will remain until October, working with organoids from both domestic and wild fauna, in collaboration with his colleagues at the International Livestock Research Institute (ILRI). And he's still waiting, he tells us, for all the reagents and materials sent from Barcelona to arrive.

"This African institution will send me samples from livestock here; and we have made all the requests so that the parks in Kenya can provide me with specimens that they find dead in the wild and that are still fresh and can be used. We want to make rhinoceros gas organoids, from everything we can," says this researcher, who emphasizes that their goal is "in the future to have a representation of most of the world's species."

The mini-replicas of organs they generate will have to pass all the necessary controls to ensure they do not contain any pathogens, and frozen with dry ice at -80 °C, they will be sent to the CReSA biobank in Barcelona. A copy will remain at ILRI and, in addition, Ceada will transfer the knowledge of how to make these organoids to its African colleagues.

Search without animal experimentation

The biobank was created with the aim of testing which species are susceptible to pathogens so that, in the event of a new COVID-19 or flu outbreak, it would be possible to identify which animals could be infected and spread the pathogens. And this, Ceada points out, would allow for early containment measures, especially if the animals come into contact with humans, such as livestock.

Once the organoid is created, it can be used infinitely, without the need for new samples. "We can infect them again and again with new pathogens and see how they respond each time," Kochanowski points out.

In this sense, he explains that, in the context of avian flu, In a case in which a variant of H5N1 began to jump from birds to cows, the CReSA Animal Health team decided to conduct an experiment with ten species for which they had organoids to, on the one hand, test the effectiveness of using this technology to evaluate the animals' susceptibility to infection and, on the other hand, to these two pathogens.

Thus, they exposed organoids from animals such as llamas, chickens, pigs, ferrets, and wolves to H5N1 and also to the swine fever virus, H1N1. As expected, they saw that some animals were only susceptible to one of the two pathogens, as is the case with pigs and birds. Surprisingly, some species, such as llamas, were infected but developed mild forms of the disease, which could turn them into reservoirs.

And others, such as wolves, "are very susceptible to both viruses." The organoid cells of this carnivore died shortly after being infected with both avian influenza and swine fever, Kochanowski adds. And in fact, this is consistent with cases described in Europe of wild carnivores dying after eating other infected animals.

"We have also seen that wild ruminants do not have high mortality rates. But, although they do not die from avian influenza, they do contribute to the virus's continued circulation," warns this researcher.

Predicting future pandemics

Another possibility that organoids allow, although CReSA-IRTA has not yet begun to explore it, is to conduct conservation studies, especially in the case of endangered species. The San Diego ZooIn the US, for example, they create organoids from the skin cells of certain animals, called fibroblasts, and use them to assess whether and to what extent those species can adapt to temperature increases linked to the climate crisis.

"At the moment, we're more focused on infections, and now we've also started using them for toxicity and nutrition studies," Majó points out. And Kochanowski emphasizes that they can also be a very useful tool for "understanding some of the superpowers of some animals, such as elephants' resistance to cancer."

The biobank will be open to other research groups that need to conduct research in biomedicine and emerging or re-emerging infectious diseases. In addition, as CReSA-IRTA will have a new biosafety laboratory 3, Construction will begin at the end of 2025 and is expected to be completed in 2028. This laboratory will be able to carry out studies with pathogens such as dengue, West Nile, Chikungunya, and avian flu viruses, as well as with vectors such as mosquitoes and ticks. This laboratory is a strategic global health infrastructure, unique in Catalonia and the second in Spain with its characteristics.

Therefore, the next step, Kochanowski hopes, will be to use this technology to predict which viruses could become a problem. "This would allow us to anticipate, rather than react, which would be very useful in preparing for future new pandemics."