From Blood to Brain: NYSCF – Robertson Investigator Turns Immune Cells Into Neurons
According to a new study from NYSCF – Robertson Investigator Alumnus and NYSCF – Robertson Stem Cell Prize recipient Marius Wernig, MD, PhD, Associate Professor in the Institute for Stem Cell Biology and Regenerative Medicine and the Department of Pathology at Stanford University, making functional human neurons requires just one blood sample, four proteins, and three weeks.
Typically, to turn one type of cell into another, the cell must first be reprogrammed back into a pluripotent stem cell—a more flexible state in which the cell can be “told” what new cell type to become. However, Dr. Wernig and his team were able to successfully convert human immune cells found in the blood into functional neurons without reverting them back into stem cells.
The researchers achieved this through a process called “transdifferentiation” which allowed them to take samples of blood, expose the samples to the right sequence of proteins, and obtain functional neurons in about three weeks. This method is advantageous because it can be used on fresh or frozen blood samples (which are easily obtainable), is faster than the process of creating stem cells, and is less likely to spark genetic mutations in the new cells.
The study focused on a type of immune cell in the blood called a T cell. T cells keep us healthy by identifying and attacking harmful invaders. Although they are very different structurally and functionally from neurons, the researchers experienced little trouble getting the T cells to take on the characteristics of a skinny, electrically active neuron.
“It’s kind of shocking how simple it is to convert T cells into functional neurons in just a few days,” says Dr. Wernig. “T cells are very specialized immune cells with a simple round shape, so the rapid transformation is somewhat mind-boggling.”
The neurons Dr. Wernig and his team created are not able to form mature connections with other neurons, but they are able to perform the other main functions of a neuron. This makes them an effective tool for studying how neurons become dysfunctional in disorders such as autism or schizophrenia. In fact, the team has already begun collecting blood samples from children with autism to study the cellular basis of the disorder.
“We now have a way to directly study the neuronal function of, in principle, hundreds of people with schizophrenia and autism,” says Dr. Wernig. “For decades we’ve had very few clues about the origins of these disorders or how to treat them. Now we can start to answer so many questions.”