They are mice with human immune systems—dubbed Personal Immune (PI) mice—and they are important tools in the study of type 1 diabetes (T1D). A mouse with a human’s immune system?
The process of creating a PI mouse starts with a sample of bone marrow taken from a human donor’s bone. A single bone marrow stem cell, harvested from a simple aspiration, scientists say, has the ability to create all the different cells in the immune system. Those human immune cells are put into a specially engineered mouse—one that has no immune system of its own. The final result is a PI mouse—one that has a human immune system generated from that donor’s bone marrow.
So far, most of the bone marrow donors for PI mice have been T1D patients at the Naomi Berrie Diabetes Center, (each bone marrow aspiration creates up to 30 PI mice). This provides researchers a one-of-a-kind opportunity to study everything from the genesis to the genetics of human T1D and other autoimmune diseases, according to immunologist, Megan Sykes, MD, the Michael J. Friedlander Professor of Medicine at Columbia and the pioneer of PI Mice.
The study of human autoimmunity presents many challenges for scientists. For one thing, by the time a patient presents with T1D, he or she may have had the disease for some time, so it is not clear what initiated the illness. By recreating the human immune system from scratch in PI mice, researchers may be able to determine what is fundamentally different about that T1D-prone immune system, before the disease even develops.
Now, Dr. Sykes’s team of scientists at the Center for Translational Medicine at Columbia are working with the Berrie Center to recruit bone marrow donors both with and without T1D to study the causes of autoimmunity, using PI Mice. Among the many things scientists would like to learn from the mice, said Nicole Danzl, PhD, an associate research scientist in Dr. Sykes lab, “we hope to find out what is fundamentally different about patients’ immune systems compared with those of healthy individuals.”
Dr. Danzl, who is in charge of the recruitment of bone marrow donors for the upcoming project, says, “the people with T1D that I talk to are excited about the PI mouse project. They are mainly motivated to participate by their interest in science and trying to fully understand their own disease. Many T1D patients are very attuned to what’s happening in research and the news. They are reading academic papers. This clinical research is a way to help basic science and be involved in research intended to reap large rewards. ”If you, or anyone you know, with or without T1D, might be interested in participating in the PI mice research project by becoming a bone marrow donor, please discuss the possibility with your doctor.