NIH reverses ban on human-animal chimera research

On 4 August, the US federal agency National Institutes of Health (NIH) announced that it would lift the funding moratorium that it had imposed on HIH-funded researchers, prohibiting them from creating chimeras. Chimera-based studies involve adding human pluripotent stem cells to animal embryos to create blends called chimeras. In September 2015, NIH had not only imposed a ban on chimera studies but had also suspended funding for these projects. However, many NIH-funded researchers protested this move citing it as a threat to the progress of stem cell research and regenerative medicine. While NIH has decided to lift the ban now, it has stated that a panel will be set up to review grant applications for chimera studies.

Researchers primarily use chimera models to study human diseases in animal models. However, the main objective of chimera research is to grow human organs in animal models that can be harvested and transplanted into humans. Chimera research has been a controversial topic of debate in scholarly circles since it is highlights several ethical concerns. Chimeras are neither humans nor animals; therefore, researchers have expressed worries about the lack of guidelines on how these blended models should be treated. There are also apprehensions about such research leading to the creation of a new breed of animals that have human intelligence or human appearance. To address these issues, NIH has tightened its guidelines: Researchers will be allowed to introduce human stem cells in non-human primate embryos only after the blastocyst stage to prevent the chimera brain from having too many human cells. Additionally, the breeding of chimeras will be prohibited to prevent the humanization of chimera offspring.

The revised policy has elicited mixed reactions. Some researchers have expressed excitement that chimera research will continue, whereas others are not convinced about the changed focus of the NIH policy. Ali Brivanlou, a developmental biologist at the Rockefeller University in New York City, opines that rather than scrutinizing the timing of modification of the animal embryo, NIH’s focus should be on determining and limiting the percentage of human characteristics in a chimera. To consider any other concerns that might be raised by the science community as well as the public, this policy is open for public comment for 30 days, following which NIH will finalize the guidelines and the ban on chimera research will be officially lifted.    

Reference

US agency lifts ban on funding human-animal hybrids

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