The molecule interleukin-7 (IL-7) is an important immune system messengers that a sufficient number of T cells guaranteed at present in the body's defenses. ETH Zurich researchers have now shown that IL-7 has another important function: it improves the function of the lymphatic drainage collect moisture that has leaked from the blood vessels into the body tissues and back into the bloodstream. In the future, these insights for lymphedema patients, the lymphatic system is not working properly useful, what tissue to become fluid retention and swelling.
The predisposition to the development of lymphedema can on the one hand, are hereditary. On the other hand, lymphedema often. During the period after a tumor operation Primary tumors are surgically excised tumor and lymph nodes are often removed because they can contain metastases. Tumor in the course of such a surgical procedure is the lymphatic tissue is damaged. This tissue fluid is often not properly arranged, so that the occurrence of lymphedema in 20 to 30 percent of patients.
No drug treatment yet
Currently wearing the only treatment options for patients with lymphedema compression stockings and undergoing a medical manual lymphatic drainage massage therapist. "In IL-7, we have a molecule and a mechanism for improving lymphatic drainage for lymphedema therapy, useful to be discovered," says study leader Cornelia Halin, Assistant Professor of Drug Discovery Technologies.
In their study, the researchers found that IL-7, which shape is formed by the so-called endothelial cells. The lymphatic vessel wall These cells also bear receptors, IL-7 in a certain way based on the lock-and-key principle. "Although we have not formally proven that so far, we assume that the lymphatic endothelial cells produce the neurotransmitter, may directly affect their own function," says Halin. To date, IL-7 is one of only a few molecules have been identified that support lymphatic drainage. A few years ago, researchers discovered that the other endogenous growth factor VEGF-C, a molecule of interest in this context is perhaps also.
Findings from an animal model
Halin and her colleagues showed the drainage support function of IL-7 by drainage experiments in mice, where blue, albumin-binding dye in the skin of the mouse injected ear. It is noteworthy that albumin, a naturally occurring protein that is transported from the tissues via the lymphatics. By quantifying the dye in the tissue remained one day after the injection, the researchers were able to determine how well worked the lymphatic these animals.
In carrying out this experiment, mice, in which a functional IL-7 receptor, it is noted that these mice to only remove half the dye out of the ear skin in order to compare with a functional mouse IL-7 receptor. However, they observed a significant increase in lymphatic drainage in mice with increased IL-7 production. Finally she IL-7 protein is in a third experiment, unchanged administered healthy mice and found that a therapeutic treatment done to improve lymphatic drainage function.
Been tested in patients
The researchers are now planning similar experiments in mice in which lymph vessels are surgically destroyed, similar to the situation in patients after cancer surgery. Here, the researchers want to test whether treatment with IL-7 or IL-7 could lymphedema would be prevented. Reduce the existing lymphedema administered
The long-term goal is to explore the potential of IL-7-based drugs for lymphedema. In particular, IL-7 has been tested in clinical trials, although for different indications: due to its immune-stimulatory activity on T cells, IL-7 is currently undergoing in patients with immunodeficiency diseases such as HIV or hepatitis infection or bone marrow tested transplants.