In children and adolescents, the thymus gland functions as a "school for T cells". The organ in our chest is where the precursors of those T cells that would later attack the body's own cells are discarded. Epithelial cells in the thymus present a large number of molecules that occur in the body to the future T cells. If any of them reacts to one of these molecules, a self-destruction program is triggered. T cells that attack the body's own molecules remaining intact and multiplying, on the other hand, can cause autoimmune diseases.

New mechanism discovered

In Nature, the team led by Thomas Korn, Professor of Experimental Neuroimmunology at TUM and a Principal Investigator in the SyNergy Cluster of Excellence, and Ludger Klein, Professor of Immunology at LMU’s Biomedical Center (BMC), describe another previously unknown mechanism behind this.

In addition to the precursors of T cells, the thymus gland also contains other immune cells, the B cells. They develop in the bone marrow but migrate to the thymus in early childhood. "The function of B cells in the thymus gland has been a mystery that has puzzled immunologists for many years," says Thomas Korn. The researchers have now been able to show for the first time that B cells play an active role in teaching T cells which targets not to attack.