Schrijver, D. P. | Search bioRxiv

bioRxiv2025

Single-cell spatial analysis of pediatric high-grade glioma reveals a novel population of SPP1+/GPNMB+ myeloid cells with immunosuppressive and tumor-promoting capabilities

BackgroundPediatric-type diffuse high-grade gliomas (pHGG) are a leading cause of pediatric cancer-related mortality. Although immunotherapy offers a promising treatment avenue, clinical responses in pHGG patients remain limited. A detailed understanding of the tumor immune microenvironment (TIME) is essential for advancing immunotherapeutic strategies. MethodsWe performed single-cell spatial analysis integrating cyclical immunofluorescence imaging and Spatial Molecular Imaging to interrogate the proteomic and transcriptomic landscape of pHGG. A tissue microarray comprising 32 diagnostic patient-derived pHGG samples was utilized to map the spatial distribution of immune and tumor cells. ResultsOur analyses reveal that the pHGG TIME is predominantly composed of myeloid cells, including brain-resident microglia and monocyte-derived macrophages, with only few T cells. A significant subset of these myeloid cells express mesenchymal-like genes and are positive for SPP1 and GPNMB. Spatial mapping further demonstrated that SPP1+/GPNMB+ myeloid cells localize in close proximity to mesenchymal-like tumor cells, and negatively correlate with the location and presence of CD8+ T cells. These cells also express genes related to immunosuppression and epithelial-to-mesenchymal transition, indicating their potential role in establishing an immunosuppressive niche. ConclusionsOur findings reveal a distinct immune landscape in pHGG characterized by SPP1+/GPNMB+ myeloid cells which may contribute to the exclusion of CD8+ T cells. This spatially resolved insight identifies these myeloid cells as promising therapeutic targets and provides a rationale for developing novel immunotherapeutic strategies to improve outcomes in pediatric high-grade gliomas.

cancer biology↗

bioRxiv2023

DNA storage in thermoresponsive microcapsules for repeated random multiplexed data access

Owing to its longevity and extremely high information density, DNA has emerged as an attractive medium for archival data storage. Scalable parallel random access of information is a desirable property of any storage system. For DNA-based storage systems, however, this yet has to be robustly established. Here we develop thermoconfined PCR, a novel method that enables multiplexed, repeated random access of compartmentalized DNA files. Our strategy is based on stable localization of biotin-functionalized oligonucleotides inside microcapsules with temperature-dependent membrane permeability. At low temperatures, microcapsules are permeable to enzymes, primers, and amplified products, while at high temperatures membrane collapse prevents molecular crosstalk during amplification. We demonstrate that our platform outperforms non-compartmentalized DNA storage with respect to repeated random access and reducing amplification bias during multiplex PCR. Using fluorescent sorting, we additionally demonstrate sample pooling and data retrieval by barcoding of microcapsules. Our thermoresponsive microcapsule technology offers a scalable, sequence-agnostic approach for repeated random access of archival DNA files.

synthetic biology↗