The role of B cells in the enhancement of pollen allergy – reaction to non-allergenic compounds

The team of Prof. Carsten Schmidt-Weber and Prof. Jan Gutermuth of the Center of Allergy & Environment (ZAUM) at Helmholtz Zentrum München and TU München investigated the influence of pollen extract of common ragweed, also known as Ambrosia artemisiifolia*, on B cells.

These cells can produce immunoglobulin E (IgE**), the key trigger and an important diagnostic marker of allergic reactions. “We were able to show that pollen extract enhances the secretion of allergy driving IgE antibodies in vitro and in vivo”, explains Dr. Sebastian Öder who is leading author of the study together with Dr. Francesca Alessandrini. “Moreover, our colleagues at the Swiss Institute of Allergy and Asthma Research (SIAF) confirmed this effect also for human B cells.”

By excluding various substances, the scientists tested which components exactly caused the reaction. Therefore, B cells were either exposed to the main Ambrosia allergen Amb a 1, the pollen associated substance PPE1*** or the total extract and a protein/allergen free fraction of the extract, respectively.

“Interestingly, all substances increased the respective immune reaction of the B cells, except Amb a 1”, Öder says. Therefore, the authors conclude that the enhanced secretion of IgE is independent of the main allergen Amb a 1, but is rather induced by small compounds like PPE1.

Mechanism not only relevant for Ambrosia

„Until now it was assumed that the allergy promoting effect of non-allergenic plant compounds was mainly mediated by dendritic cells. The new mechanism that we found therefore allows a different view on this issue and furthermore offers new starting points for the development of therapies against allergic diseases”, says Schmidt-Weber, director of ZAUM****.

To test the relevance of their results, the Helmholtz researchers also investigated the effect of other pollen extracts like from birch, pine and timothy grass. They showed that the effect plays a role not only for Ambrosia, but is also relevant for trees and grasses.

“In the future we are planning to investigate the effect of climatic changes on the B cell mediated allergenicity of pollen, since climatic changes may impact the composition of pollen”, comments Prof. Claudia Traidl-Hoffmann. She is director of the Christine Kühne – Center for Allergy Research and Education (CK-CARE), which provided considerable financial support for the study.

Further information

Background:
* Common ragweed (Ambrosia artemisiifolia) probably once came to Europe in imported birdseed. Now it is widely dispersed here due to climate change. Ragweed pollen is very aggressive; in the U.S. it is now the main cause of hay fever and other allergies. Since Ambrosia does not bloom until late summer, it thus lengthens the “season” for allergy sufferers.

** IgE (immunoglobulin E) is the term referring to a class of antibodies which are considered to be the main cause of allergic reactions in the body. If an IgE molecule binds to an allergen, it can induce so-called mast cells to release histamine, which ultimately triggers the allergic reaction. The actual task of IgE is the defense against parasites and worms.

*** PPE1 stands for the substance E1-Phytoprostane and is a so-called pollen-associated lipid mediator which is able to influence the immune system.

**** In recent years researchers discovered that besides allergens, there are also other compounds of pollen which can affect allergic reactions. Recently the group at ZAUM showed that the substance adenosine can enhance the allergenic effect of Ambrosia pollen (https://www.tum.de/en/about-tum/news/press-releases/short/article/32444/). However, it was so far unknown that also B cells can be triggered by these compounds to increase the production of allergy type antibodies.

Original publication:
Oeder, S. et al. (2015). Pollen derived non-allergenic substances enhance Th2-induced IgE production in B-cells. Allergy, DOI: 10.1111/all.12707

As German Research Center for Environmental Health, Helmholtz Zentrum München pursues the goal of developing personalized medical approaches for the prevention and therapy of major common diseases such as diabetes mellitus and lung diseases. To achieve this, it investigates the interaction of genetics, environmental factors and lifestyle. The Helmholtz Zentrum München has about 2,300 staff members and is headquartered in Neuherberg in the north of Munich. Helmholtz Zentrum München is a member of the Helmholtz Association, a community of 18 scientific-technical and medical-biological research centers with a total of about 37,000 staff members.

The Institute of Allergy Research (IAF) investigates the molecular mechanisms behind the development of allergies, which are on the rise around the world. Through intensive cooperation among scientists and clinicians on individual approaches to prevention, the IAF is working to halt this epidemiological spread. In the therapeutic area, the institute's scientists want to develop new approaches specifically targeted at the patients. The IAF works with the Technische Universität München in the joint Center of Allergy & Environment (ZAUM) facility. The IAF is also a member of the Munich Allergy Research Center (MARC) and the German Center for Lung Research (DZL).

The Center of Allergy & Environment (ZAUM) in Munich is a joint undertaking by the Helmholtz Zentrum München and the Technical University of Munich (TUM). This cooperation, which is the only one of its kind in the German research landscape, is dedicated to interdisciplinary basic research and forms a link between clinicians at the hospital and clinical research staff at the university. Thanks to this approach, findings about the mechanisms that lie behind allergies are translated into preventive and therapeutic measures. The development of effective, individually tailored treatments enables better care to be provided for allergy-sufferers. www.zaum-online.de

Technische Universität München (TUM) is one of Europe’s leading research universities, with around 500 professors, 10,000 academic and non-academic staff, and 36,000 students. Its focus areas are the engineering sciences, natural sciences, life sciences and medicine, reinforced by schools of management and education. TUM acts as an entrepreneurial university that promotes talents and creates value for society. In that it profits from having strong partners in science and industry. It is represented worldwide with a campus in Singapore as well as offices in Beijing, Brussels, Cairo, Mumbai, and São Paulo. Nobel Prize winners and inventors such as Rudolf Diesel and Carl von Linde have done research at TUM. In 2006 and 2012 it won recognition as a German “Excellence University.” In international rankings, it regularly places among the best universities in Germany.

Contact for the media:
Department of Communication, Helmholtz Zentrum München – German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg – Phone: +49 89 3187 2238 – Fax: +49 89 3187 3324 – E-mail: presse@helmholtz-muenchen.de

Scientific contact at Helmholtz Zentrum München:
Dr. Sebastian Öder, Helmholtz Zentrum München – German Research Center for Environmental Health (GmbH), Institute of Allergy Research and Center of Allergy & Environment, Ingolstädter Landstr. 1, 85764 Neuherberg – Phone +49 89 3187 3978 – E-mail: sebastian.oeder@helmholtz-muenchen.de

Dr. Francesca Alessandrini, Helmholtz Zentrum München – German Research Center for Environmental Health (GmbH), Institute of Allergy Research and Center of Allergy & Environment, Ingolstädter Landstr. 1, 85764 Neuherberg – Phone +49 89 3187 2524 – E-mail: franci@helmholtz-muenchen.de

http://www.ncbi.nlm.nih.gov/pubmed/26214762 – Link to the original publication
http://www.helmholtz-muenchen.de/en/news/press-releases/2015/index.html – Press releases Helmholtz Zentrum München
http://www.helmholtz-muenchen.de/iaf – Institute for allergy research