Scientists have developed ‘mini’ organs that can end animal experiments

Animal testing is almost always required to develop and test new treatments or vaccines for humans, but this can raise ethical concerns about treating animals and often takes years to complete.

As an alternative, researchers have developed a new testing platform that encapsulates B cells in miniature “organoids” to rapidly screen vaccines and greatly reduce the number of animals needed. A study published in a scientific journal details this development ACS Central SciencePublished by the American Chemical Society.

Vaccines are designed to introduce the immune system to an antigen, which can be part or all of a virus or bacterium, allowing the body to prepare itself for future exposure by programming its B cells to produce antibodies against the antigen. Some bacteria coat themselves in polysaccharide “camouflage”, which requires special conjugated vaccines, such as those that protect against pneumonia and meningitis.

However, how conjugate vaccines induce immune responses with B cells is not fully understood.

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Traditional ways of testing vaccines involve injecting them into animals and waiting weeks or months for results. When developing an entirely new class of vaccine or focusing on a new target, scientists often have to evaluate many vaccine candidates, which requires many animal studies.

This method is time-consuming, unreliable and cruel to animals, which are just some of the reasons why the medical community is trying to find alternatives to using animals in this way.

“There are many reasons to move away from the use of animals in medical research in favor of innovative scientific methods that have been developed and improved over time,” Elizabeth Baker, Esq., Director of Research Policy at the Physicians Committee for Responsible Medicine (PCRM) ), tells VegNews.

“This includes the opportunity to better understand human disease by focusing on human data rather than hoping that what happens in other animal species will be relevant to human disease,” Baker said. “Also, [this includes] Animals suffer and die for science, which is not consistent with how society views the treatment of animals.”

Alternatives to animal testing

To speed up the process and address ethical concerns, researchers have begun exploring the use of organoids, which are small groups of cells that act like miniature organs, creating a simulated environment that mirrors in vivo conditions.

According to the study, hundreds of immune cell organoids can be generated from the spleen of a single animal, greatly increasing the throughput of the experiment. So, researchers Matthew DeLisa, Ankur Singh and colleagues wanted to see if this approach would deliver similar results to animal tests and if the platform could be used to screen large numbers of glycoconjugate vaccine candidates.

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To create the organoids, the researchers isolated B cells from mouse spleens, added cellular signaling molecules and structural components, then encased everything in a synthetic hydrogel matrix. Next, they developed conjugate vaccine candidates targeting the bacteria responsible for tularemia, or “rabbit fever,” for which an approved vaccine does not currently exist.

Candidates were tested using both traditional in-vivo mouse trials and the new organoid platform. B cells respond similarly to both formats and provide insight into several biochemical changes that occur as the cells become antibody-producing cells.

As a result, the team found that the platform could be used to identify B cell clones that produce highly antigen-specific antibodies, which has a variety of potential applications. Although this work is preliminary, the researchers say the organoid platform could help reduce the time it takes to develop and evaluate new conjugate vaccines.

Is animal testing even necessary?

Last year, more than 800 physicians, scientists and health professionals joined PCRM to call on medical journals. nutrients To stop publishing animal studies that violate the publication’s own ethical guidelines.

The nutritional guidelines for the authors clearly require “replacement of animal by substitutes where possible”. Still, in a letter to the journal’s editors-in-chief, the group pointed to several published studies in which tests were performed on small animals despite alternatives being readily available.

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The letter states that these articles reveal, nutrients Showing young researchers that it is okay to violate ethical orders and that journals will publish their research anyway.

“Animal tests are accepted because they’ve been used for decades, because they haven’t demonstrated their value,” says Baker. “When tested, animal tests continue to fail. Increasing momentum is moving the field away from animal use and toward modern methods because modern methods represent better science, which can only benefit patients, animals and even business.”

PCRM is a medical community of 17,000 physicians and 175,000 members working with government and industry to replace the use of animal testing with modern methods. “It’s becoming increasingly well-known and understood that animal experiments will be replaced by new technologies that continue to evolve,” Baker said.

“Many non-animal and human-specific methods are already available and commercialized,” she says. “These include in vitro experiments that incorporate human biology rather than other animal species — such as organoids and organ chips — as well as computer models that use human data to better model human outcomes.”

Baker also noted that more non-animal methods are being developed and will continue to become available, and that federal agencies are committed to the integration of non-animal methods. In addition, Congress continues to show support for non-animal methods and recently provided millions of dollars to the FDA to reduce animal use.

“The barriers to transplantation are not scientific—they are policy, educational and psychological,” Baker concludes. “Our team and many others are working to address these challenges so that science can move away from animal use.”