A recent report on the ethics of crossing species boundaries by inserting human cells into nonhuman animals – research surrounded by debate – makes recommendations clarifying the moral issues and calling for improved oversight of this work.

The report, “Creating Chimeric Animals — Looking for Clarity On Ethics and Oversight,” was developed by an interdisciplinary team, with funding from the National Institutes of Health. Principal investigators are Josephine Johnston and Karen Maschke, research scholars at The Hastings Center, and Insoo Hyun, director of the Center for Life Sciences and Public Learning on the Museum of Life Sciences in Boston, formerly of Case Western Reserve University.

Advances in human stem cell science and gene editing enable scientists to insert human cells more extensively and precisely into nonhuman animals, creating “chimeric” animals, embryos, and other organisms that contain a mixture of human and nonhuman cells.

Many individuals hope that this research will yield enormous advantages, including higher models of human disease, inexpensive sources of human eggs and embryos for research, and sources of tissues and organs suitable for transplantation into humans.

But there are ethical concerns about this sort of research, which raise questions similar to whether the moral status of nonhuman animals is altered by the insertion of human stem cells, whether these studies needs to be subject to additional prohibitions or oversight, and whether this sort of research needs to be done in any respect.

The report found that:

• Animal welfare is a primary ethical issue and needs to be a spotlight of ethical and policy evaluation in addition to the governance and oversight of chimeric research.
• Chimeric studies raise the potential for unique or novel harms resulting from the insertion and development of human stem cells in nonhuman animals, particularly when those cells develop within the brain or central nervous system.
• Oversight and governance of chimeric research are siloed, and public communication is minimal. Public communication needs to be improved, communication between the various committees involved in oversight at each institution needs to be enhanced, and a national mechanism created for those involved in oversight of those studies.
• Scientists, journalists, bioethicists, and others writing about chimeric research should use precise and accessible language that clarifies fairly than obscures the moral issues at stake. The terms “chimera,” which in Greek mythology refers to a fire-breathing monster, and “humanization” are examples of ethically laden, or overly broad language to be avoided.

Source:

Journal reference:

Johnston, J., et al. (2022) Clarifying the ethics and oversight of chimeric research. Hastings Center Report. doi.org/10.1002/hast.1426.