CD Laboratory for Complement Research

The CD Laboratory is researching the properties of C4d, a protein of the innate immune system. The aim is to conduct a feasibility study on the use of C4d receptor agonists as a possible therapy for diseases characterised by an excessive immune response.

As part of innate immunity, the complement system plays an important role in fighting pathogens by helping antibodies and phagocytes to eliminate pathogens. In addition, the complement system has a crucial position in the removal of immune complexes and apoptotic material and thus contributes to the maintenance of immune homeostasis.

The activation and regulation of the complement system leads to the formation of complement fragments, such as the protein C4d. Preliminary work has shown that inhibitory surface molecules found on monocytes, macrophages and dendritic cells act as specific cellular receptors for C4d.

Defects in the complement system are associated with autoimmune diseases such as systemic lupus erythematosus and the detection of C4d is considered a marker for antibody-mediated rejection reactions in donor kidneys. However, the mechanisms that contribute to the maintenance of immune tolerance in the context of complement activation have only been insufficiently investigated. The specific interaction of C4d with inhibitory receptors could represent a new paradigm for the maintenance of tolerance to endogenous, i.e. harmless, structures.

In this project, the mechanisms underlying the immunomodulatory properties of the C4d molecule will be investigated in detail. In addition, C4d-based receptor antagonists will be developed as potential therapeutics for diseases associated with misdirected immune responses and tested in animal models.