New study provides insights into the skin's innate immune system
Researchers at the University Medical Center Freiburg find a possible approach to the therapy of the butterfly disease. The key role in this approach is the connective tissue protein collagen VII. Until now, the protein was only regarded as an anchor of stability for the skin, but the research group demonstrated in a recent study that collagen VII also plays a central role in innate immune defense. It was previously unknown that the connective tissue protein also occurs in the spleen and lymph organs and has important functions there.
In particular, patients with dystrophic epidermolysis bullosa (EB), better known as butterfly disease, could benefit from the latest study results. Collagen VII is missing in EB sufferers, which can lead to tearing of the skin and blistering at the slightest strain. The scientists were able to demonstrate in mice that the protein is not only found on the skin but also in the spleen. From there, collagen VII controls the intensity with which immune cells attack bacteria. The results of the study were published in the journal "Proceedings of the National Academy of Sciences" (PNAS) and can lead to a better understanding and new therapies of the butterfly disease.
A completely new player in the control of the immune system
"It is now clear that connective tissue molecules like collagen VII are active components of the innate immune system," says Dr. Alexander Nyström, research group leader of the study in a press release. This brings a completely new player in the control of the immune system to the scene. Without the connective tissue protein, the skin is colonized more bacterially and infections can occur. This was also confirmed in the blood test of 30 patients affected by the butterfly disease. So far, doctors and scientists assumed that the many wounds and the mechanical sensitivity of the skin of butterflies were responsible for the increased bacterial colonization.
The protein cochlin enhances the innate immune response
Comparisons of mice that were unable to produce collagen VII with healthy animals showed that collagen VII occurs in the spleen and binds and releases the protein cochlin there. Cochlin in turn enhances the innate immune response. In animals that could not form collagen VII, the level of cochlin in the blood was also significantly reduced. The blood test in 30 human patients gave the same results. Artificial delivery of collagen VII into the spleen of the animals led to a normalization of the cochlin value. As a result, the bacterial colonization of the skin also decreased. Even cochling through food improved the immune response.
The skin's bacterial balance is not well understood
According to the University Medical Center Freiburg, the skin of numerous healthy bacteria is also colonized by healthy people. These are important for our health and take on protective functions. Incorrectly composed bacterial settlements can also cause diseases such as skin infections. In the worst case, bacteria on the skin can even support the development of skin cancer. How the balance of "good" and "bad" bacteria on the skin is maintained has not been well understood so far. (fp)