Programmbereich Asthma und Allergie
Allergic inflammation to environmental agents (such as house dust mite or plant pollens) is considered an aberrant immune response to otherwise harmless factors. Hence, the elucidation of the chemical structure of biologically active and clinically important molecules is an essential foundation to understand its function and mode of action. Likewise, the identification of the cellular and molecular mechanisms of the immune system involved in the effector response to environmental agents, is critical to comprehend their pathologic inflammatory reaction.
The IgE-mediated immune response triggered against allergens (proteins) from pollen and house dust mite during atopic (allergic) asthma has been widely explored. However, proteins are not the sole components present in these allergenic agents. In the recent years, it has become more evident that the allergen sources are composed of variety of chemical structures, including lipids, that are delivered to the host together with allergens, thus influencing the course of allergic sensitization. Such molecules have different biological functions, e.g. in pollen grains are required for its hydration and germination. In addition, the existence of many allergens able to bind lipid species (e.g. Der p 5, Der p 7) suggests their presumably important function.
In contrast to peptides, which are recognized by conventional T cells when displayed on class I and II major histocompatibility complex molecules (MHC- I and -II); lipids are recognized by so-called unconventional CD1-restricted T cells, including Natural Killer T cells and γδ T cells.
The concept of the group is based on the hypothesis that lipid species influence the allergic sensitization, either leading to protection by the induction of tolerance; or to exacerbation of the established allergic reaction (see Figure).
Therefore, it is necessary to explore the – to a large extent - unknown field of (glyco)-lipid containing substances in order to fully understand the mechanisms of reactions to allergenic molecules.
- Glycolipids of house dust mites – studying the impact of allergen-lipid association
In the frame of basic flagship project entitled “Impact of allergen-lipid association on sensitization and asthma phenotype development” (coordinated by Prof. U. Jappe) within the DZL (Deutscheszentrum für Lunge Forschung, German Center for Lung Research) we examine lipid and glycolipid content of the house dust mite extracts in the context of their putative adjuvant effect.
- Pollen glycolipids and mediators – on the hunt of (glyco)-lipids in the allergic reaction
In this project we aim to isolate and characterize all lipid species present in Timothy grass (Phleum pratense) pollen that are involved in the development of type 2 immune responses related to allergic inflammation. One branch of the research involves studying the lipid mediators (phytoprostanes), that we believe play a role in the initial phase of sensitization (priming). The second one deals with the glycolipids being a structural part of the pollen grain (e.g. glycoglycerols, ceramides) that are important for the second phase of the sensitization (amplification).