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Biology subjects

Bosio, A.

Publications and source records attributed to Bosio, A..

6 recordsLinked to original sources

Minimizing time in culture: A prototypic autologous manufacturing workflow for monoclonal iPSC lines within seven weeks

Induced pluripotent stem cells (iPSCs) hold great promise for both allogeneic and autologous cellular therapies. However, broad application and clinical translation is hindered by fragmented, complex and time-intensive workflows, resulting in high manufacturing costs, poor standardization and increased risk of genomic aberrations in derived iPSCs. In this study we developed a standardizable, automatable and time-efficient process for the derivation of monoclonal iPSC lines straight from skin including a comprehensive and cascaded QC strategy. We generated monoclonal iPSC lines derived from human skin punch biopsies of ten donors (age 49-81) via mRNA-based reprogramming that subsequently underwent comprehensive and thorough characterization of phenotypic and genetic properties. The use of a combined mechanical and enzymatic fibroblast isolation protocol and a transient non-integrative reprogramming technology allowed us to obtain 78 monoclonal iPSC lines, ready for banking, molecular characterization and further differentiation within seven weeks from initial sample processing to passage four iPSC lines. The phenotypical characterization via flow cytometry-based pluripotency marker expression and 2D-directed differentiation into the three germ layers showed low intra- and inter-donor variability over all generated lines. A combination of SNP array based CNV analysis followed by whole exome sequencing proved to be the most efficient approach for assessment of genomic integrity. Proof-of-concept experiments for closed system processing revealed that a substantial part of the most error-prone and technically demanding steps can be transferred to semi-automated, closed systems. In conclusion, the described protocol allows for time-efficient, standardizable and automatable generation of high-quality monoclonal iPSC lines from human skin punch biopsies within seven weeks, thus moving the field of autologous iPSC manufacturing one step further towards cost-efficient clinical implementation.

cell biology↗

Integrated 3D Light-Sheet and 2D Multiplex Imaging for Deep Histological Profiling of a Somatic Mouse Glioblastoma Model

Glioblastoma is a devastating brain cancer. Despite intense research, patient survival has not significantly increased over the past decades and efficient treatment is currently not available. Therefore, the fundamental understanding of the disease, based on the development of relevant animal models, combined with the development of efficient tools for their deep analysis, represents a priority. Neural Stem cells in the subventricular zone of the forebrain have been identified as cells of origin for glioblastoma, leading to the development of new somatic lineage models based on in vivo brain electroporation. While such models have been characterized in depths by sequencing approaches, systematic histological analyses are currently scarce. Here we present the multimodal histological characterization of a transgenesis independent somatic glioblastoma model in mice. Using 3D light sheet imaging we demonstrate that the model is highly reproducible, allowing quantitative evaluation of tumor growth over large cohorts. Using multiplex imaging by MICS technology we systematically characterize the cellular landscape and molecular composition of the induced tumors, as well as their micro- and macro-environments, and provide a resource of mouse compatible antibodies for cancer research. Finally, we use the model to show that tissue clearing and 3D light sheet microscopy of whole brains can be combined with subsequent multiplex imaging, allowing deep spatial characterization of the tumor proteome in pre-identified brain regions.

cancer biology↗

Discovery of rare antigen-specific TCRs via replicate profiling

Development of effective vaccines and targeted immunotherapies for cancer, autoimmunity, allergy, and infectious diseases requires comprehensive understanding of functionality and antigenic specificity of involved T cell clones. A major technical challenge remains the high-throughput identification of antigen-specific T cells. Here, we present a rapid cost-efficient TCR discovery assay starting from PBMC that enables ultra-sensitive discovery of clonal alpha-beta paired TCRs responding to individual or pooled peptides. In a small-scale experiment with a single donor, assay identified over 90 SARS-CoV-2-specific CD4+ and CD8+ TCR{beta} clonotypes, validated by clonal tracking and comparison against known SARS-CoV-2-specific TCRs. Positioning within the scRNA-Seq map revealed distinct helper T cell subsets involved in primary and secondary response. Further validation in a cohort of five donors identified nearly 1,000 CD4+ and CD8+ TCR clonotypes specific to viral and fungal peptide antigens. The assay demonstrated exceptional sensitivity in capturing low-frequency clones and allowed accurate TCR/TCR{beta} pairing, validated using single-cell transcriptomics. The ability to capture low-frequency antigen-specific TCRs, combined with detailed scRNA-Seq annotation, establishes an integrated pipeline that links antigen-responsive clones to their precise functional phenotypes. This platform provides a robust foundation for dissecting T cell roles in health and disease and accelerates the development of vaccines and immunotherapies.

immunology↗

Integrated spatial protein and RNA analysis on the same section using MICS technology

Spatial Biology has evolved from the molecular characterization of microdissected cells to high throughput spatial RNA and protein expression analysis at scale. The main limitation of spatial technologies so far is the inability to resolve protein and RNA information in the same histological section. Here, we report for the first time the integration of highly multiplexed RNA and protein detection on the same tissue section. We developed a new, automated, spatial RNA detection method (RNAsky), which is based on targeted rolling circle amplification and iterative staining. We combine RNAsky with MACSima Imaging Cyclic Staining (MICS) based protein analysis and show compatibility with subsequent standard hematoxylin and eosin (H&E) staining. Using both, open-source tools and our recently developed software suite MACS(R) iQ View, we demonstrate our multiomics MICS workflow by characterizing key immune-oncology markers at subcellular resolution across normal and diseased tissues.

molecular biology↗

Morphofunctional deficits in the cerebral cortex of NeuroD2 mutant mice are associated with autism/schizophrenia-like behaviors

We identified seven families associating NEUROD2 pathogenic mutations with ASD and intellectual disability. To get insight into the pathophysiological mechanisms, we analyzed cortical development in Neurod2 KO mice. Cortical projection neurons (CPNs) over-migrated during embryogenesis, inducing abnormal thickness and laminar positioning of cortical layers. At juvenile ages, dendritic spine turnover and intrinsic excitability were increased in L5 CPNs. Differentially expressed genes in Neurod2 KO mice were enriched for voltage-gated ion channels, and the human orthologs of these genes were strongly associated with ASD. Furthermore, adult Neurod2 KO mice exhibited core ASD-like behavioral abnormalities. Finally, by generating Neurod2 conditional mutant mice we demonstrate that forebrain excitatory neuron-specific Neurod2 deletion recapitulates cellular and behavioral ASD phenotypes found in full KO mice. Our findings demonstrate crucial roles for Neurod2 in cortical development and function, whose alterations likely account for ASD and related symptoms in the newly defined NEUROD2 mutation syndrome.

neuroscience↗

Identification, Isolation, and Characterization of Human LGR5-positive Colon Adenoma Cells

The intestine is maintained by stem cells located at the base of crypts and distinguished by the expression of LGR5. Genetically engineered mouse models have provided a wealth of information about intestinal stem cells, while less is known about human intestinal stem cells due to difficulty detecting and isolating these cells. We established an organoid repository from patient-derived adenomas, adenocarcinomas, and normal colon, which we analyzed for variants in 71 colorectal cancer (CRC) associated genes. Normal and neoplastic colon tissue organoids were analyzed by immunohistochemistry and fluorescent-activated cell sorting for LGR5. LGR5-positive cells were isolated from 4 adenoma organoid lines and were subjected to RNA-sequencing. We found that LGR5 expression in the epithelium and stroma was associated with tumor stage, and by integrating functional experiments with LGR5-sorted cell RNA-seq data from adenoma and normal organoids, we found correlations between LGR5 and CRC- specific genes, including DKK4 (dickkopf WNT signaling pathway inhibitor 4) and SMOC2 (SPARC related modular calcium binding 2). Collectively, this work provides resources, methods and new markers to isolate and study stem cells in human tissue homeostasis and carcinogenesis.

cancer biology↗