This press release is available in German.
T-cells are the immune system's security force. They seek out pathogens and rogue cells in the body and put them out of action. Their precursors are formed in the bone marrow and migrate from there into the thymus. Here, they mature and differentiate to perform a variety of tasks. Scientists at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg have now succeeded for the first time in observing the maturation of immune cells in live zebrafish embryos. During their development, the immune cells migrate into and out of the thymus more than once. The zebrafish is thus an ideal animal model for studying the dynamic processes of immune cell development.
The thymus is a small, inconspicuous organ, but it is also vital for a functional immune system. This is because it is the development site of the T-lymphocytes (T-cells), which play a central role in the body's immune defences. Their precursors come from the bone marrow and are lured into the thymus by chemical attractants called chemokines. Once in the thymus, they develop into different T-cell types, which are eventually deployed into the rest of the body.
A research team at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg has now succeeded for the first time in observing these processes live. They have tracked the real-time development of T-cells in living zebrafish embryos, starting with the formation of the thymic anlage (the cluster of embryo cells from which the thymus develops), via the cells' migration into the organ from the bone marrow, right up to the stage when the fully formed T-cells are released from the thymus.
As the researchers discovered, this is a highly dynamic process: the precursor cells do not take a direct migration route into the thymus. Instead, they seem "undecided" and
|Contact: Dr. Thomas Boehm|