Researchers discover a protein that plays a critical role in the development of allergic airway inflammation.

Worldwide, there are more than 300 million asthma patients. In Germany alone, 10-15% of children suffer from allergic asthma that is often impaired by environmental pollutants. With the medications available today, symptoms can be effectively relieved, but without tackling the root cause. The precise reasons as to why certain people suffer from allergic asthma are still not fully clear. Tobias Polte and his team from the Department of Environmental Immunology at the Helmholtz Centre for Environmental Research (UFZ) collaborated with Jan Simon and his colleagues from the Clinic for Dermatology, Venereology and Allergology at the University of Leipzig and have recently been successful in discovering a molecule that plays a significant role in the development of allergic airway inflammation — as demonstrated in their recent publication in Nature Communications.

The protein syndecan-4 is found in the cell membrane of antigen presenting cells (APCs). These are immune cells that detect exogenous substances (antigens). They internalize them and migrate to the nearest lymph node, where they present them to other immune cells, namely T-cells. In this way they initiate an immune reaction that leads to sensitization to a particular antigen, like for example to a pollen allergen. It is upon renewed contact with this pollen allergen that the typical symptoms of allergic asthma arise. “In our study we were able to demonstrate that syndecan-4 plays a critical role in APC migration,” says Polte. “When syndecan-4 is lacking, the APCs cannot find their way to the T-cells and consequently cannot activate them. As a result, the immune reaction cannot take place and the sensitization to a particular antigen ceases.”

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