Biology subjects

Scheeren, F.

Publications and source records attributed to Scheeren, F..

3 recordsLinked to original sources

bioRxiv2024

Temperature-based MHC class-I multimer peptide exchange for human HLA-A, B and C

T cell recognition of specific antigens presented by major histocompatibility complexes class-I (MHC-I) can play an important role during immune responses against pathogens and cancer cells. Detection of T cell immunity is based on assessing the presence of antigen-specific cytotoxic CD8+ T cells using MHC class-I (MHC-I) multimer technology. Previously we have designed conditional peptides for HLA-A*02:01, H-2Kb and HLA-E that form stable peptide-MHC-I-complexes at low temperatures and dissociate when exposed to a defined elevated temperature. The resulting conditional MHC-I complex can easily and without additional handling be exchanged with a peptide of interest, allowing to exchange peptides in a ready-to-use multimer and a high-throughput manner. Here we present data that this peptide-exchange technology is a general applicable, ready-to-use and fast approach to load many different peptides in MHC-I multimers for alleles of the HLA-A, HLA-B and HLA-C loci. We describe the development of conditional peptides for HLA-A*03:01, HLA-A*11:01, HLA-B*07:02 and HLA-C*07:02 that only form stable peptide-MHC-I complexes at low temperatures, allowing peptide exchange at higher defined temperature. We document the ease and flexibility of this technology by monitoring CD8+ T cell responses to virus-specific peptide-MHC complexes in patients. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/630039v2_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@1a48592org.highwire.dtl.DTLVardef@3d5f24org.highwire.dtl.DTLVardef@13160b7org.highwire.dtl.DTLVardef@c4bb19_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIT cell immunity relies on antigen-specific CD8+ T cells recognizing peptide MHC-I complexes. C_LIO_LIEstablishing temperature-based peptide exchange across multiple HLA alleles, resulting in a robust, easy, and fast system to generate peptide MHC-I complexes. C_LIO_LITemperature-based MHC class-I multimer demonstrate applicability across major MHC-I gene families for monitoring CD8+ T cell responses. C_LIO_LIEasy high-throughput peptide exchange potential, enhancing clinical utility of MHC multimer technology. C_LI

immunology↗

bioRxiv2024

Design and synthesis of DNA origami nanostructures to control TNF receptor activation

Clustering of type II tumour necrosis factor (TNF) receptors (TNFRs) is essential for their activation, yet currently available drugs fail to activate signalling. Some strategies aim to cluster TNFR by using multivalent streptavidin or scaffolds based on dextran or graphene. However, these strategies do not allow for control of the valency or spatial organisation of the ligands, and consequently control of the TNFR activation is not optimal. DNA origami nanostructures allow nanometre-precise control of the spatial organization of molecules and complexes, with defined spacing, number and valency. Here, we demonstrate the design and characterisation of a DNA origami nanostructure that can be decorated with an engineered single-chain TNF-related apoptosis-inducing ligand (SC-TRAIL) complexes, which show increased cell killing compared to SC-TRAIL alone on Jurkat cells. The information in this chapter can be used as a basis to decorate DNA origami nanostructures with various proteins, complexes or other biomolecules.

synthetic biology↗

bioRxiv2023

A fluorescence-based sensor screen identifies MED12 as a potential microsatellite instability regulator in colon cancer

Inactivation of the DNA mismatch repair (MMR) system, due to (epi)genetic alterations of MMR genes, increases the frequency of mutations across the genome, creating a phenotype known as microsatellite instability (MSI). Cancers with this phenotype have been associated with a better prognosis for some time, but only since recently it has been recognised as a predictive biomarker of response to immunotherapy. Because MSI tumours accumulate more insertions and/or deletions in coding regions of the genome containing microsatellites, there is an increase in neoantigens resulting from reading frame shifts, which promotes immunogenicity. To investigate if additional genes exist that can cause an MSI phenotype, we developed a fluorescence-based sensor to identify genes whose inactivation increases the rate of frameshift mutations on microsatellite sequences in cancer cells. Using genome-scale CRISPR/Cas9 screens, we identified MED12 as a potential new regulator of microsatellite instability. Consistent with this, we found that MED12 mutant colon cancers that lack mutations in the known MMR genes are more likely to be of the MSI phenotype.

cancer biology↗