技术资料

IntroductionAmid the persistent threat of future pandemics,the continuous evolution of SARS-CoV-2 exposed critical challenges for vaccine efficacy and therapeutic interventions,highlighting the need for rapid and adaptable approaches to respond to immune escape variants.MethodsHere,we report the use of immortalized B cell libraries from human peripheral blood mononuclear cells (PBMCs) and tonsil tissues to uncover B cell clones exhibiting cross-reactive neutralization against various SARS-CoV-2 variants and perform directed evolution of immortalized B cell clones to produce antibodies with improved binding and neutralization against emerging SARS-CoV-2 variants.ResultsImmortalization of PBMC and tonsil-derived human B cells was achieved through transduction with retroviral vectors encoding apoptosis inhibitors,yielding transduction efficiencies of 67.5% for PBMCs and 50.2% for tonsil-derived cells. Analysis revealed that immortalized B cell libraries produced with this method retain diverse immunoglobulin isotype representations. Through high-throughput functional screening of approximately 40,000 B cells per library,we identified 12 unique clones with neutralization activity for SARS-CoV-2,leading to selection of monoclonal antibodies with robust neutralization activity against Delta and BA.5 variants. We applied our directed evolution approach to libraries generated by ex vivo AID-induced somatic hypermutation (SHM) of immortalized B cell clones to enhance the affinity and cross-reactivity,resulting in improved binding and neutralization potency to escape variants such as EG.5.1 and JN.1. Furthermore,we engineered a bi-paratopic antibody combining KBA2401,a broadly neutralizing antibody binding to highly conserved epitope on Spike-RBD,and KBA2402,a broadly binding non-neutralizing antibody,resulting in enhanced potency against SARS-CoV-2 variant JN.1 and KP.3.DiscussionOur findings illustrate the use of immortalized B cell libraries for development of therapeutics that adapt to viral evolution and highlight the application of ex vivo directed evolution in refining antibody responses against emerging immune escape SARS-CoV-2 variants. The approach here described offers a promising pathway for rapid therapeutic development in the face of evolving viral threats. View Publication

Programmable epigenome editors modify gene expression in mammalian cells by altering the local chromatin environment at target loci without inducing DNA breaks. However,the large size of CRISPR-based epigenome editors poses a challenge to their broad use in biomedical research and as future therapies. Here,we present Robust ENveloped Delivery of Epigenome-editor Ribonucleoproteins (RENDER) for transiently delivering programmable epigenetic repressors (CRISPRi,DNMT3A-3L-dCas9,CRISPRoff) and activator (TET1-dCas9) as ribonucleoprotein complexes into human cells to modulate gene expression. After rational engineering,we show that RENDER induces durable epigenetic silencing of endogenous genes across various human cell types,including primary T cells. Additionally,we apply RENDER to epigenetically repress endogenous genes in human stem cell-derived neurons,including the reduction of the neurodegenerative disease associated V337M-mutated Tau protein. Together,our RENDER platform advances the delivery of CRISPR-based epigenome editors into human cells,broadening the use of epigenome editing in fundamental research and therapeutic applications. Epigenome editing programs gene silencing without inducing DNA breaks but challenges in delivery into human cells limit its broader use. Here,the authors present the RENDER platform,which uses virus-like particles to enable CRISPR-based epigenome editing for durable gene silencing in human cells. View Publication

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy with a poor prognosis and limited therapeutic options. Leukemic stem cells (LSCs),which drive disease progression and confer resistance to therapy,pose a significant challenge to conventional treatment strategies. In this study,we identified and characterized the inhibitory mechanisms of TH37,a small molecule derived from traditional Chinese medicine,which selectively targets AML blasts and LSCs. Our analyses identified peroxiredoxin 1 (PRDX1),an enzyme that catalyzes the breakdown of hydrogen peroxide (a reactive oxygen species),as the primary molecular target of TH37. We demonstrated that TH37 directly interacts with PRDX1,inhibiting its enzymatic activity and thereby elevating intracellular reactive oxygen species levels in AML cells. PRDX1 was found to be overexpressed in AML,and its expression correlated with poor prognosis and the activation of AML- and cancer-associated pathways. Targeting PRDX1,either through lentiviral short-hairpin RNA-mediated silencing or TH37 treatment,induced apoptosis,reduced colony formation,and impaired the engraftment and growth of AML cells in immunodeficient mouse models. Furthermore,TH37 synergized with conventional chemotherapeutic agent to significantly reduce the viability and colony-forming capacity of AML cells. These findings demonstrate the critical role of PRDX1 in AML pathogenesis and highlight its potential as a key therapeutic target to improve clinical outcomes for AML patients. View Publication

Hantaviruses are zoonotically transmitted from rodents to humans through the respiratory route,with no currently approved antivirals or widely available vaccines. The recent discovery of interhuman-transmitted Andes virus (ANDV) necessitates the systematic identification of cell tropism,infective potential,and potent therapeutic agents. We utilized human primary lung endothelial cells,various pluripotent stem cell-derived heart and brain cell types,and established human lung organoid models to evaluate the tropisms of Old World Hantaan (HTNV) and New World ANDV and Sin Nombre (SNV) viruses. ANDV exhibited broad tropism for all cell types assessed. SNV readily infected pulmonary endothelial cells,while HTNV robustly amplified in endothelial cells,cardiomyocytes,and astrocytes. We also provide the first evidence of hantaviral infection in human 3D distal lung organoids,which effectively modeled these differential tropisms. ANDV infection transcriptionally promoted cell injury and inflammatory responses,and downregulated lipid metabolic pathways in lung epithelial cells. Evaluation of selected drug candidates and pharmacotranscriptomics revealed that the host-directed small molecule compound urolithin B inhibited ANDV infection and restored cellular metabolism with minimal changes in host transcription. Given the scarcity of academic BSL-4 facilities that enable in vivo hantaviral studies,this investigation presents advanced human cell-based model systems that closely recapitulate host cell tropism and responses to infection,thereby providing critical platforms to evaluate potential antiviral drug candidates. Author summaryHantaviruses are fatal human pathogens that cause hemorrhagic fevers and are classified into either Old World or New World groups. Though most hantaviruses utilize zoonotic transmission,the New World Andes virus (ANDV) is unique in its ability to spread between humans. This distinct transmission mode underscores the need to investigate its cell tropism,pathogenicity,and therapeutic targets. Thus,we performed a systems-level comparison of the Old World Hantaan virus (HTNV) and New World hantaviruses,ANDV and Sin Nombre virus (SNV),using human lung,heart,and brain cell models,alongside lipidomic and transcriptomic profiling. We observed that ANDV exhibits broad tropism,infecting all tested cell types,including lung epithelial cells. HTNV replicated in lung endothelial,heart,and brain cells,whereas SNV replication was largely confined to lung endothelial cells. Notably,ANDV infection induced stronger host transcriptional changes,promoted cell injury and inflammatory responses,and suppressed lipid metabolic pathways in lung epithelial cells. Further drug testing and pharmacotranscriptomic analysis identified effective inhibitors of ANDV infection,including urolithin B,that restored cellular metabolism with minimal transcriptional disruption. This study provides a comparative framework for understanding hantavirus cell tropism and host responses and highlights potential antiviral candidates for treating these severe viral infections. View Publication

Angelman syndrome is a rare neurodevelopmental disorder caused by the loss of function of the maternally inherited UBE3A gene within the chr15q11-q13 region. This gene is subjected to a tissue-specific form of genomic imprinting leading to the silencing of the paternal allele in neurons. Angelman syndrome can result from various (epi)genetic mechanisms,with paternal uniparental disomy of chromosome 15 (patUPD15) being one of the rarest and least studied due to the absence of suitable models. To address this gap,we generated three independent induced pluripotent stem cell (iPSC) lines from individuals with Angelman syndrome caused by patUPD15,alongside genetically matched unaffected familial controls. Peripheral blood mononuclear cells (PBMCs) were reprogrammed into iPSCs using a non-integrative Sendai virus-based approach expressing the Yamanaka factors. All iPSC lines underwent rigorous quality control,confirming stem cell identity,trilineage differentiation potential,and genetic and epigenetic integrity. This newly established iPSC toolkit provides a powerful platform to investigate the molecular underpinnings of Angelman syndrome caused by patUPD15,paving the way for future translational research and therapeutic development tailored for this understudied form of the disorder. The online version contains supplementary material available at 10.1007/s13577-025-01287-8. View Publication

5-Ethynyl-2′-deoxyuridine (EdU) has revolutionized DNA replication and cell cycle analyses through fast,efficient click chemistry detection. However,commercial EdU kits suffer from high costs,proprietary formulations,limited antibody multiplexing capabilities,and difficulties with larger biological specimens. Here,we present OpenEMMU (Open-source EdU Multiplexing Methodology for Understanding DNA replication dynamics),an optimized,affordable,and user-friendly click chemistry platform utilizing off-the-shelf reagents. OpenEMMU enhances efficiency,brightness,and multiplexing capabilities of EdU staining with both non-conjugated and conjugated antibodies across diverse cell types,including T cell activation and proliferation assays. We validated its effectiveness for the fluorescent imaging of nascent DNA synthesis in developing embryos and organs,including embryonic heart,forelimbs,and 3D hiPSC-derived cardiac organoids. OpenEMMU also enabled the deep-tissue 3D imaging of DNA synthesis in zebrafish larvae and under replication stress in embryos at high spatial resolution. This approach opens new avenues for understanding organismal development,cell proliferation,and DNA replication dynamics with unprecedented precision and flexibility. Subject areas: Biochemistry,Cell biology,Developmental biology,Computational bioinformatics View Publication

Human induced pluripotent stem cell (hiPSC) derived neurons are powerful tools to model disease biology in the drug development space. Here we leveraged a spectrum of neurophysiological tools to characterize iPSC-derived NGN2 neurons. Specifically,we applied these technologies to detect phenotypes associated with presynaptic dysfunction and rescue in NGN2 neurons lacking a synaptic vesicle associated protein MUNC18-1,encoded by syntaxin binding protein 1 gene (STXBP1). STXBP1 homozygous knock out NGN2 neurons lacked miniature post synaptic currents and demonstrated disrupted network bursting as assayed with multielectrode array and calcium imaging. Furthermore,knock out neurons released less glutamate into culture media,consistent with a presynaptic deficit. These synaptic phenotypes were rescued by reconstitution of STXBP1 protein by AAV transduction in a dose-dependent manner. Our results identify a complementary suite of physiological methods suitable to examine the modulation of synaptic transmission in human neurons. View Publication

The principal organization of mammalian neuromuscular junctions (NMJs) shares essential features across species. However,human NMJs (hNMJs) exhibit distinct structural and physiological properties. While recent advances in stem-cell-based systems have significantly improved in vitro modeling of hNMJs,the extent to which these models recapitulate in vivo development remains unclear. Here,we performed temporal transcriptomic analysis of human three-dimensional (3D) neuromuscular co-cultures,composed of iPSC-derived motoneurons and skeletal muscle engineered from primary myoblasts. We found that the expression pattern follows a temporally coordinated gene expression program underlying NMJ maturation. The model recapitulates transcriptional features of NMJ development,including early myoblast fusion and presynaptic development,followed by a late-stage upregulation of postsynaptic markers and embryonic AChR subunits. Importantly,comparable transcriptional dynamics across two independent hiPSC lines confirm the reproducibility and robustness of this system. This study confirms on a transcriptional level that human 3D neuromuscular co-cultures are a robust and physiologically relevant model for investigating hNMJ development and function. View Publication

Neural crest stem cells (NCSCs) compose a highly migratory,multipotent,stem cell population arising from the neural plate border of the embryonic ectoderm. Investigating the development of NCSCs is critical in understanding both embryonic development and abnormal events that underlie neurocristopathies. Suggested seeding densities in in vitro human induced pluripotent stem cells (hiPSCs) differentiation protocols,varying between 10,000 cells/cm 2 and 200,000 cells/cm 2,demonstrate a lack of consensus on the optimal conditions to obtain NCSCs. Aiming to maximize the differentiation efficiency of hiPSCs towards the NCSCs lineage,we investigated the effect of the initial seeding density on NCSCs lineage commitment,both in fibroblast- and human peripheral blood mononuclear cell (PBMC)-derived hiPSCs. Cultures were characterized with gene and protein expression analysis assessing stemness ( OCT3/4 and NANOG ),neural crest identity ( SNAI2 and SOX10 ) and neuroectoderm identity ( PAX6 and SOX1 ). We demonstrate that reaching a confluent monolayer of cells by the end of the differentiating protocol is crucial to obtaining NCSCs from hiPSCs. To achieve this,our results indicated 17,000 cells/cm 2 is the optimal initial seeding density. Under this protocol,a confluent monolayer was reached after 8 days of differentiation and an average of 89% SOX10 positive cells were obtained. The fold change of SNAI2 and SOX10 expression was 11-fold and 17-fold higher,respectively,in cultures seeded with 17,000 cells/cm 2,compared to the highest tested density of 200,000 cells/cm 2 . In contrast,seeding 200,000 cells/cm 2 induced neuroectoderm-like cells,confirmed by an average of 45% of cells marking positive for PAX6. With this work,we demonstrate the importance of achieving cellular confluency during NCSCs differentiation. View Publication

Sac1 is a conserved phosphoinositide phosphatase,whose loss-of-function compromises cell and organism viability. Here,we employ acute auxin-inducible Sac1 degradation to identify its immediate downstream effectors in human cells. Most of Sac1 is degraded in ~1 h,paralleled by increased PI(4)P and decreased cholesterol in the trans-Golgi network (TGN) during the following hour,and superseded by Golgi fragmentation,impaired glycosylation,and selective degradation of TGN proteins by ~4 h. The TGN disintegration results from its acute deacidification caused by disassembly of the Golgi V-ATPase. Mechanistically,Sac1 mediated TGN membrane composition maintains an assembly-promoting conformation of the V0a2 subunit. Key phenotypes of acute Sac1 degradation are recapitulated in human differentiated trophoblasts,causing processing defects of chorionic gonadotropin,in line with loss-of-function intolerance of the human SACM1L gene. Collectively,our findings reveal that the assembly of the Golgi V-ATPase is controlled by the TGN membrane via Sac1 fuelled lipid exchange. This study employs auxin-inducible degradation of Sac1. The authors reveal that acute Sac1 depletion changes the Golgi membrane lipid composition,causing disassembly of the Golgi V-ATPase and eventually resulting in cargo processing defects. View Publication

BackgroundA growing body of evidence from primate embryos as well as in vitro systems supports the notion that amnion and primordial germ cell (PGC) lineage progressing cells share a common precursor.ResultsTo gain comprehensive transcriptomic insights into this critical but poorly understood precursor and its progeny,we examine the evolving transcriptome of a developing human pluripotent stem cell-derived model of amnion and PGC formation at the single cell level. This analysis reveals several continuous amniotic fate progressing states with state-specific markers. Additionally,a progenitor-like cell,that displays bi-potential characteristics for amnion and PGC-like cell lineages and is marked by CLDN10,is identified. Strikingly,we find that expression of CLDN10 is restricted to the amnion-epiblast boundary region in our human post-implantation amniotic sac model as well as in peri-gastrula cynomolgus macaque embryos; moreover,this boundary region presents amnion and PGC progenitor-like transcriptional characteristics. Furthermore,our loss of function analysis shows that CLDN10 promotes amniotic but suppresses PGC-like fate.ConclusionsOverall,based on the single cell transcriptomic resource in this study,we identify a CLDN10+ amnion and PGC progenitor-like population at the amnion-epiblast boundary of the primate peri-gastrula,and present additional molecular clues as to how amnion and PGC may be formed at the amnion-epiblast boundary in human peri-gastrula. Supplementary InformationThe online version contains supplementary material available at 10.1186/s13059-025-03751-y. View Publication

Immune rejection is one of the most serious challenges in allogeneic transplantation,including allogeneic induced pluripotent stem cell (allo-iPSC)-derived cell therapy. Beta-2-Microglobulin gene-knockout,human leukocyte antigen (HLA) class I-deficient iPSCs can evade immune rejection by host T cells,which occurs due to HLA mismatches. However,natural killer (NK) cells recognize HLA class Ⅰ-deficient cells and reject them,which is known as the missing-self response. Introducing chimeric HLA-E protein to HLA class Ⅰ-deficient iPSCs suppresses the missing-self response of NK cells expressing the inhibitory receptor NKG2A; however,technology to suppress NKG2A-negative NK cells is still required. Here,we developed novel agonists for the other inhibitory receptor,killer immunoglobulin receptor (KIR),on NK cells. We found that antibodies that bind to activating KIR enhance NK cell activation and developed selective agonists for inhibitory KIRs (KIR2DL1,KIR2DL2/3,and KIR3DL1). Introducing these selective inhibitory KIR agonists on T cells and HLA class Ⅰ-deficient iPSCs allowed them to evade immune rejection by NK cells. Additionally,we identified an NKG2A-selective agonist as an alternative to chimeric HLA-E,which stimulates the activating receptor NKG2C. This technology enhances immune tolerance in allo-iPSCs and facilitates the development of various iPSC-derived regenerative medicines. The online version contains supplementary material available at 10.1038/s41598-025-18394-z. Subject terms: Allotransplantation,NK cells View Publication