Where is the lymphatic vessel going?
The results suggest that the immune cells actually use a combination of touch and smell when patrolling the skin tissue. They follow the concentration gradient of signal molecules, which are not soluble, but are bound to sugar molecules in the connective tissue. When the researchers labeled the immune cells and the signal substance chemokine CCL21, they observed that the chemokine emanates exclusively from lymphatic vessels. It spreads in the surrounding tissue and thus forms a concentration gradient. However, it does not remain mobile like an odorant, but anchors itself permanently to sugar molecules.
Researchers tracked the system by mapping maps of the chemokine distribution and comparing them to the cell's migration routes. As it turns out, the immune cells find their way to the next lymphatic vessel by sensing the concentration of chemokine on their surface and then moving toward the higher concentration. To test this, the researchers "flooded" the test tissue with chemokine. The result confirmed the assumption that the immune cells wandered around - they were no longer able to find the lymphatic vessel. display
The fact that the signal molecules are not soluble, but bound to connective tissue molecules, has a convincing reason: If the groundbreaking substance were soluble, pressure on the tissue would cause fluid turbulence that would destroy the gradient. An anchored lead structure, on the other hand, is insensitive.
According to the researchers, the results could provide important information for the development of therapies and medicines. Michael Sixt emphasizes: "It is important to understand how immune cells move and orient themselves. Only then can we reasonably think about strategies to influence their behavior. "Michael Sixt (Institute of Science and Technology) et al .: Science, 10.1126 / science.1228456 © science.de - Martin Vieweg