A signalling molecule known as Axl has been discovered on immune cells of the epidermis. This recently published finding provides new insight into the development of important skin immune cells known as Langerhans cells. These cells fight off invading microorganisms and play a crucial role in our health.
As the research project, funded by the Austrian Science Fund FWF, also discovered, the natural production of the signalling molecule Axl is highly dependent on the messenger substance TGF-beta1. Together, these findings provide a better understanding of how immune cells develop and offer new approaches for the treatment of autoimmune diseases.
Some infections can really "get under your skin". Fortunately, however, this is not always the case, as the skin provides very effective protection against infections - a function for which we have to thank a type of skin cells, known as the Langerhans cells (LCs). These cells are found in the outermost layer of the skin, the epidermis, and on mucous membranes, and provide a first line of defence against invading viruses, bacteria and fungi. A team of researchers at the Medical University of Vienna is currently examining how immune cells develop from haemopoietic or blood-forming stem cells, and recently made some very important discoveries in the process.
A team headed by Prof. Herbert Strobl from the Institute of Immunology has not only demonstrated that a signalling molecule known as Axl occurs on the surface of LCs, but also how this process is controlled by the messenger substance or cytokine transforming growth factor beta 1 (TGF-beta1). Commenting on the significance of this study, Prof. Strobl explains that: "A large number of benign microbes are found on the skin, which are important for human health. The ability to distinguish "good" from "bad" is therefore of critical importance for the LCs - and Axl plays an important role in this process."
Axl is, in fact, a receptor belonging to the family of TAM receptor tyrosine kinases. These messenger molecules have a crucial function in the prevention of undesired inflammatory responses - and are thereby also preventing the immune system from reacting to benign microbes. Finding an explanation for when and how Axl is formed is therefore very important for understanding the development of LCs from stem cells.
The group headed by Prof. Strobl, who recently started at the Institute of Pathophysiology and Immunology at the Medical University of Graz, has now succeeded in showing that precursor LCs form the signalling molecule Axl just a few hours after coming into contact with TGF-beta1. In comparison to the duration of other cell differentiation processes, an astonishingly short time period. In addition, the researchers established that Axl is only produced in cells that go on to differentiate into LCs - and not in precursors that develop into other cell types, for example granulocytes, monocytes or lymphocytes. The scientists also succeeded in determining that Axl is the only receptor of the TAM family synthesised under these conditions.
These findings rapidly indicated to Thomas Bauer, first author of the study, that the effect of TGF-beta1 on Axl production is vital for LC differentiation from precursor cells: A detail that is further substantiated by the fact that the continuous presence of TGF-beta1 is essential throughout the differentiation process to guarantee Axl synthesis.
A SYSTEMATIC APPROACH
These findings have now been published in the prestigious Journal of Experimental Medicine. This study, which is impressive from both a qualitative and quantitative perspective, was made possible by a well-established test system, as Prof. Strobl explains: "Thanks to an in vitro cell culture procedure for LC differentiation from isolated blood stem cells, we can analyse the effects of different molecules during LC differentiation in detail. This is exactly what we did with TGF-beta1."
The importance of the findings of this FWF project extends far beyond the fundamental insights they provide into the development of skin immune cells. Axl´s ability to distinguish between "good" and "bad" also enables it to prevent autoimmune diseases. Which is why these findings just may contribute to the treatment of these diseases in the future.
Original publication: T. Bauer, A. Zagorska, J. Jurkin, N. Yasmin, R. Koffel, S. Richter, B. Gesslbauer, G. Lemke and H. Strobl, Identification of Axl as a downstream effector of TGF-beta1 during Langerhans cell differentiation and epidermal homeostasis. J. Exp. Med. 2012 Vol. 209 No. 11 2033-2047. DOI 10.1084/jem.20120493Scientific Contact:
Judith Sandberger | PR&D
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
Chlamydia: How bacteria take over control
28.03.2017 | Julius-Maximilians-Universität Würzburg
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Physics and Astronomy
28.03.2017 | Health and Medicine
28.03.2017 | Life Sciences