Peptide Boronic Acids: Unveiling Exciting Opportunities in Immunology

Peptides are chains made up of two or more amino acids that connect together, found in every cell throughout an organism. They are crucial to the immune system as they carry important immunological markers that inform the body of foreign entities. The sequence and composition of these peptides are key in determining what the immune system identifies as foreign, prompting an immune response. Therefore, therapeutic or preventive immunizations often utilize peptides, as noted by Marius Werner, a doctoral student affiliated with both Heidelberg institutes. Researchers are particularly interested in boronic acids due to their distinctive and untapped interaction capabilities with immune cells and other biological targets.

In their recent study, the researchers synthesized peptides with boronic acids by performing hydroboration on resin-bound peptide alkenes and alkynes. This method resulted in a unique chemical structure that had proven to be either unattainable or extremely challenging to achieve in the past. “The presence of boronic acid facilitates the introduction of additional chemical modifications to the peptides, allowing for a multitude of variations. Given that boronic acids also interact with immune cells, the peptides enhanced with this component could potentially be leveraged to influence immune system activity,” explains Junior Professor Dr. Franziska Thomas from the Institute of Organic Chemistry, who led the research alongside Prof. Dr. Christian Klein from the Institute of Pharmacy and Molecular Biotechnology.

Although there is still a significant journey ahead, Prof. Klein suggests that these new compounds could potentially trigger an immune response against tumor cells, thereby utilizing the body’s inherent mechanisms to eliminate a tumor. Another possible application includes the directed release of therapeutic agents within the body. The boronic acid group is designed to act as an “anchor” for the peptide, enabling it to attach to nanoparticles that serve as delivery vehicles. “The particles carrying the peptide can be crafted to ensure they are absorbed by specific organs or cells, particularly within the immune system, making it possible for the peptide to exert effects that are managed by its design,” states the expert, who specializes in medicinal chemistry. Moreover, peptide boronic acids might also be utilized in conjunction with small biodegradable implants that gradually release active substances within the body.

This innovative research was part of the “Synthetic Immunology” spotlight initiative within the “Engineering Molecular Systems” Flagship Project at Heidelberg University, which is supported by the Excellence Strategy from both federal and state governments. As part of this initiative, various application potentialities are being investigated. The findings of this research have been documented in a scientific article published in the journal “Advanced Science”.