Experiments on mice have shown that three “transcription factors” jointly force the stem cell in the direction of the T cell. Transcription factors are proteins that regulate the reading of DNA. “T cells develop in the thymus, an organ located above the heart. There, the stem cells are exposed to signals that activate these transcription factors. It now turns out that the first factor puts the other two to work. They then divide up the work: one suppresses the tendency of the stem cell to become a different immune cell and the other one stimulates the stem cell to become a T cell. That way, the stem cell can only go one way: towards becoming a T cell”, says Prof. Staal.
He explains that the experiments to clarify this were technically incredibly complicated and went beyond immunology. His team therefore collaborated with colleagues from the Human Genetics department. “Lucia Daxinger’s group know a great deal about epigenetics, for example, which we at the Immunology department are less at home with. This result really is an example of fantastic multidisciplinary collaboration.”