Biology subjects

Haapaniemi, E.

Publications and source records attributed to Haapaniemi, E..

6 recordsLinked to original sources

bioRxiv2026

NFATC2 in pancreatic cancer-associated fibroblasts predicts treatment response and facilitates ERBB-targeted therapies

Pancreatic ductal adenocarcinoma (PDAC) remains a lethal malignancy, with therapeutic resistance influenced by a dense desmoplastic stroma dominated by cancer-associated fibroblasts (CAF). Using single-cell RNA-sequencing and gene regulatory network modeling of 42 PDAC tumors, we identified a CAF subpopulation characterized by elevated NFATC2 expression that is enriched in patients with improved therapeutic response and survival. NFATC2+ CAFs exhibited tumor-suppressive features, including enhanced apoptotic signaling and suppression of ERBB pathway activity. Co-culture experiments demonstrated that NFATC2+ CAFs restrain pancreatic cancer cell growth and enhance chemotherapy-induced apoptosis, increasing sensitivity to standard-of-care chemotherapy regimens and synergizing with ERBB-targeted therapies. The favorable effect of NFATC2+ CAFs on chemotherapy response was validated in two other PDAC cohorts and in rectal cancer. Together, these findings identify NFATC2+ CAFs as a therapy-conditioned stromal state linked to improved treatment response and uncover a context-dependent vulnerability within the tumor microenvironment that may be exploited to rationally optimize combination therapies.

cancer biology↗

bioRxiv2026

Protocol for Non-viral HDR-based CRISPR/Cas9 platform for small custom editing in primary T cells

CRISPR/Cas9 enables precision gene editing via HDR for mutation correction and disease modelling. This protocol describes an 8-day non-viral HDR workflow for editing primary patient and healthy donor T cells, including reagent design, editing, on-target detection, and flow cytometry. The protocol was developed under research-grade conditions but supports scaling up and the transition to preclinical and clinical GMP workflows. For complete details on the use and execution of this protocol, please refer to Mamia et al.[1]. Before you beginCRISPR/Cas9 gene editing is a promising tool to correct pathogenic variants for autologous cell therapies, targeting monogenic diseases such as inborn errors of immunity (IEI). Furthermore, it can be used as a tool for disease modelling to study normal and pathological variations of the immune system. Here we present a detailed protocol for an efficient and customizable T cell single nucleotide variant (SNV) correction platform based on homology-directed repair (HDR). The protocol details every step of the process, which starts with custom CRISPR/Cas9 reagent design of guide-RNAs (gRNAs) and repair templates for editing a novel target with no previously published reagents. Furthermore, we describe the strategy of reagent design to assess on-target HDR editing using droplet digital PCR (ddPCR). Next, we detail the T cell platform itself, and present effective strategies to stimulate PBMCs ex vivo to promote CD4+ and CD8+ T cell activation and proliferation, which we have validated in 32 unique IEI patients. Next, we present the workflow of gene editing T cells using nucleofection and CRISPR ribonucleoprotein (RNP) complexes for efficient editing that preserves high cell viabilities and up to 80% HDR. Finally, we present a flow cytometry panel that assesses the immune cells present at the end of the platform, including characterization of memory and effector T cell populations and status of T cell exhaustion. InnovationIn the study, we present a detailed protocol of performing highly efficient, non-viral and HDR-based precision editing in patient and healthy control T cells. The developed platform enables custom editing, such as correction of small pathogenic variants, with one workflow that we demonstrate to achieve up to 80% efficiency in multiple genomic loci and donors. Institutional permissionsThe study was conducted in accordance with the principles of the Helsinki Declaration and approved by the Helsinki University Central Hospital Ethics Committee, and the Regional Committee for Medical and Health Research Ethics South-East Norway. All participants have signed written informed consent.

molecular biology↗

bioRxiv2024

T cell correction pipeline for Inborn Errors of Immunity

CRISPR/Cas9 gene editing technology is a promising tool for correcting pathogenic variants for autologous cell therapies for Inborn Errors of Immunity (IEI). The present IEI correction strategies mainly focus on the knock-in of therapeutic cDNAs, or knockout of the disease-causing gene when feasible. These strategies address many single-gene defects but may disrupt gene expression and require significant optimization for each newly discovered IEI-causing gene, highlighting the need for complementary platforms that can precisely correct diverse pathogenic variants. Here, we present a safe and efficient T cell single nucleotide variant (SNV) correction pipeline based on homology-directed repair (HDR), suitable for diverse monogenic mutations. By using founder mutations of Deficiency of ADA2 (DADA2), Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and Cartilage Hair Hypoplasia (CHH) as IEI models, we show that our pipeline can achieve up to 80% bi-allelic editing, with resultant functional correction of the disease phenotype in patient T cells. We do not find detectable pre-malignant off-target effects or karyotypic, transcriptomic or proteomic aberrations upon profiling patient T cells with GUIDE-seq, single cell RNA sequencing, PacBio based long-read whole genome sequencing, and high-throughput proteomics. This study demonstrates that HDR-based SNV editing is a safe and effective option for IEI T cell correction and that it could be developed to an autologous T cell therapy, as the presented protocol is scalable for a GMP-compatible workflow. This study is a step towards the development of gene correction platform that targets a broad number of monogenic mutations. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/610811v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@1f1eb47org.highwire.dtl.DTLVardef@18dbcc2org.highwire.dtl.DTLVardef@63862dorg.highwire.dtl.DTLVardef@1fe1561_HPS_FORMAT_FIGEXP M_FIG GRAPHICAL ABSTRACT C_FIG

bioengineering↗

bioRxiv2021

Rapid genome editing by CRISPR-Cas9-POLD3 fusion

Precision CRISPR gene editing relies on the cellular homology-directed DNA repair (HDR) to introduce custom DNA sequences to target sites. The HDR editing efficiency varies between cell types and genomic sites, and the sources of this variation are incompletely understood. Here, we have studied the effect of 450 DNA repair protein - Cas9 fusions on CRISPR genome editing outcomes. We find the majority of fusions to improve precision genome editing only modestly in a locus- and cell-type specific manner. We identify Cas9-POLD3 fusion that enhances editing by speeding up the initiation of DNA repair. We conclude that while DNA repair protein fusions to Cas9 can improve HDR CRISPR editing, most need to be optimized to the particular cell type and genomic site, highlighting the diversity of factors contributing to locus-specific genome editing outcomes.

molecular biology↗

bioRxiv2018

Characterization of novel TMEM173 mutation with additive IFIH1 risk allele

TMEM173 encodes for STING that is a transmembrane protein activated by pathogen or self-derived cytosolic nucleic acids causing its translocation from ER to Golgi, and further to vesicles. Monogenic STING gain-of-function mutations cause early-onset type I interferonopathy, with disease presentation ranging from fatal vasculopathy to mild chilblain lupus. Molecular mechanisms causing the poor phenotypegenotype correlation are presently unclear. Here we report a novel gain-of-function G207E STING mutation causing a distinct phenotype with alopecia, photosensitivity, thyroid dysfunction, and STING-associated vasculopathy with onset in infancy (SAVI) -features; livedo reticularis, nasal septum perforation, facial erythema, bacterial infections and skin vasculitis. Single residue polymorphisms in TMEM173 and an IFIH1 T946 risk allele modify disease presentation in the affected multigeneration family, explaining the varying clinical phenotypes. The G207E mutation causes constitutive activation of inflammation-related pathways in HEK cells, as well as aberrant interferon signature and inflammasome activation in patient PBMCs. Protein-protein interactions further propose impaired cellular trafficking of G207E mutant STING. These findings reveal the molecular landscape of STING and highlight the complex additive effects on the phenotype.\n\nBRIEF SUMMARYNovel gain-of-function mutation in TMEM173, associated with single residue polymorphisms in TMEM173 and IFIH1, causes a distinct clinical phenotype with some shared features of SAVI.

immunology↗

bioRxiv2017

Inhibition of p53 improves CRISPR/Cas-mediated precision genome editing

We report here that genome editing by CRISPR/Cas9 induces a p53-mediated DNA damage response and cell cycle arrest. Transient inhibition of p53 prevents this response, and increases the rate of homologous recombination more than five-fold. This provides a way to improve precision genome editing of normal cells, but warrants caution in using CRISPR for human therapies until the mechanism of the activation of p53 is elucidated.

genomics↗