| dc.description.abstract | Over the past few decades, the field of drug discovery has slowly been shifting towards the
development of biotherapeutics. They offer many benefits over traditional small molecules imparted
by their high specificity such as low off-target effects and low chance of drug-drug interactions.
However, because these are large and complex biomolecules, anti-drug antibodies (ADAs) can easily
be formed reducing their efficacy and causing moderate to severe side effects. As B-cells are the cells
responsible for antibody production, inhibiting their activation may supress or completely forgo ADA
formation. To achieve this goal, we opted to link high affinity murine CD22 (mCD22) ligands to the
model antigen Ovalbumin (OVA), to examine if costimulatory binding of the inhibitory CD22
receptor can prevent OVA specific antibody formation. A novel synthetic route was developed to
synthesize large quantities of a previously reported high affinity mCD22 ligand and novel di- and
tetravalent scaffolds were developed based on existing literature and used to multimerize this mCD22
ligand. Microscale thermophoresis showed sub-micromolar binding of these di- and tetravalent ligands
to mCD22. The conjugation of these multivalent ligands to OVA was optimized and it was shown to
lead to highly increased uptake of the conjugates by splenic B-cells as seen by FACS. In vivo, the
OVA modified with the di- and tetravalent ligand showed an over ten-fold reduction in anti-OVA
IgG1 production. Unfortunately, the total antibody production against the OVA-conjugates, was not
changed. This observation likely indicates that antibodies are generated against the linker or ligand,
suggesting that this way of presentation does not (fully) supress B-cell activation. The possible reasons
as to why this was observed are discussed, and suggestions are made for further research. | |
