技术资料

Manipulation of the CD28/CTLA-4 pathway is at the heart of a number of immunomodulatory approaches used in both autoimmunity and cancer. Although it is clear that CTLA-4 is a critical regulator of T cell responses,the immunological contexts in which CTLA-4 controls immune responses are not well defined. In this study,we show that whereas CD80/CD86-dependent activation of resting human T cells caused extensive T cell proliferation and robust CTLA-4 expression,in this context CTLA-4 blocking Abs had no impact on the response. In contrast,in settings where CTLA-4(+) cells were present as regulators View Publication

The costimulation of immune cells using first-generation anti-4-1BB monoclonal antibodies (mAbs) has demonstrated anti-tumor activity in human trials. Further clinical development,however,is restricted by significant off-tumor toxicities associated with Fc$\gamma$R interactions. Here,we have designed an Fc-free tumor-targeted 4-1BB-agonistic trimerbody,1D8N/CEGa1,consisting of three anti-4-1BB single-chain variable fragments and three anti-EGFR single-domain antibodies positioned in an extended hexagonal conformation around the collagen XVIII homotrimerization domain. The1D8N/CEGa1 trimerbody demonstrated high-avidity binding to 4-1BB and EGFR and a potent in vitro costimulatory capacity in the presence of EGFR. The trimerbody rapidly accumulates in EGFR-positive tumors and exhibits anti-tumor activity similar to IgG-based 4-1BB-agonistic mAbs. Importantly,treatment with 1D8N/CEGa1 does not induce systemic inflammatory cytokine production or hepatotoxicity associated with IgG-based 4-1BB agonists. These results implicate Fc$\gamma$R interactions in the 4-1BB-agonist-associated immune abnormalities,and promote the use of the non-canonical antibody presented in this work for safe and effective costimulatory strategies in cancer immunotherapy. View Publication

Glioblastoma growth is driven by cancer cells that have stem cell properties,but molecular determinants of their tumorigenic behavior are poorly defined. In cancer,altered activity of the epigenetic modifiers Polycomb and Trithorax complexes may contribute to the neoplastic phenotype. Here,we provide the first mechanistic insights into the role of the Trithorax protein mixed lineage leukemia (MLL) in maintaining cancer stem cell characteristics in human glioblastoma. We found that MLL directly activates the Homeobox gene HOXA10. In turn,HOXA10 activates a downstream Homeobox network and other genes previously characterized for their role in tumorigenesis. The MLL-Homeobox axis we identified significantly contributes to the tumorigenic potential of glioblastoma stem cells. Our studies suggest a role for MLL in contributing to the epigenetic heterogeneity between tumor-initiating and non-tumor-initiating cells in glioblastoma. View Publication

Cell-fate transitions involve the integration of genomic information encoded by regulatory elements,such as enhancers,with the cellular environment. However,identification of genomic sequences that control human embryonic development represents a formidable challenge. Here we show that in human embryonic stem cells (hESCs),unique chromatin signatures identify two distinct classes of genomic elements,both of which are marked by the presence of chromatin regulators p300 and BRG1,monomethylation of histone H3 at lysine 4 (H3K4me1),and low nucleosomal density. In addition,elements of the first class are distinguished by the acetylation of histone H3 at lysine 27 (H3K27ac),overlap with previously characterized hESC enhancers,and are located proximally to genes expressed in hESCs and the epiblast. In contrast,elements of the second class,which we term 'poised enhancers',are distinguished by the absence of H3K27ac,enrichment of histone H3 lysine 27 trimethylation (H3K27me3),and are linked to genes inactive in hESCs and instead are involved in orchestrating early steps in embryogenesis,such as gastrulation,mesoderm formation and neurulation. Consistent with the poised identity,during differentiation of hESCs to neuroepithelium,a neuroectoderm-specific subset of poised enhancers acquires a chromatin signature associated with active enhancers. When assayed in zebrafish embryos,poised enhancers are able to direct cell-type and stage-specific expression characteristic of their proximal developmental gene,even in the absence of sequence conservation in the fish genome. Our data demonstrate that early developmental enhancers are epigenetically pre-marked in hESCs and indicate an unappreciated role of H3K27me3 at distal regulatory elements. Moreover,the wealth of new regulatory sequences identified here provides an invaluable resource for studies and isolation of transient,rare cell populations representing early stages of human embryogenesis. View Publication

Most cancer vaccines target peptide antigens,necessitating personalization owing to the vast inter-individual diversity in major histocompatibility complex (MHC) molecules that present peptides to T cells. Furthermore,tumours frequently escape T cell-mediated immunity through mechanisms that interfere with peptide presentation1. Here we report a cancer vaccine that induces a coordinated attack by diverse T cell and natural killer (NK) cell populations. The vaccine targets the MICA and MICB (MICA/B) stress proteins expressed by many human cancers as a result of DNA damage2. MICA/B serve as ligands for the activating NKG2D receptor on T cells and NK cells,but tumours evade immune recognition by proteolytic MICA/B cleavage3,4. Vaccine-induced antibodies increase the density of MICA/B proteins on the surface of tumour cells by inhibiting proteolytic shedding,enhance presentation of tumour antigens by dendritic cells to T cells and augment the cytotoxic function of NK cells. Notably,this vaccine maintains efficacy against MHC class I-deficient tumours resistant to cytotoxic T cells through the coordinated action of NK cells and CD4+ T cells. The vaccine is also efficacious in a clinically important setting: immunization following surgical removal of primary,highly metastatic tumours inhibits the later outgrowth of metastases. This vaccine design enables protective immunity even against tumours with common escape mutations. View Publication

Intracellular delivery of macromolecules is a challenge in research and therapeutic applications. Existing vector-based and physical methods have limitations,including their reliance on exogenous materials or electrical fields,which can lead to toxicity or off-target effects. We describe a microfluidic approach to delivery in which cells are mechanically deformed as they pass through a constriction 30–80% smaller than the cell diameter. The resulting controlled application of compression and shear forces results in the formation of transient holes that enable the diffusion of material from the surrounding buffer into the cytosol. The method has demonstrated the ability to deliver a range of material,such as carbon nanotubes,proteins,and siRNA,to 11 cell types,including embryonic stem cells and immune cells. When used for the delivery of transcription factors,the microfluidic devices produced a 10-fold improvement in colony formation relative to electroporation and cell-penetrating peptides. Indeed,its ability to deliver structurally diverse materials and its applicability to difficult-to-transfect primary cells indicate that this method could potentially enable many research and clinical applications. View Publication

BackgroundRecent studies highlight the critical role of microglia in neurodegenerative disorders,and emphasize the need for humanized models to accurately study microglial responses. Human-mouse microglia xenotransplantation models are a valuable platform for functional studies and for testing therapeutic approaches,yet currently those models are only available for academic research. This hampers their implementation for the development and testing of medication that targets human microglia.MethodsWe developed the hCSF1Bdes mouse line,which is suitable as a new transplantation model and available to be crossed to any disease model of interest. The hCSF1Bdes model created by CRISPR gene editing is RAG2 deficient and expresses human CSF1. Additionally,we crossed this model with two humanized App KI mice,the AppHu and the AppSAA. Flow cytometry,immunohistochemistry and bulk sequencing was used to study the response of microglia in the context of Alzheimer’s disease.ResultsOur results demonstrate the successful transplantation of iPSC-derived human microglia into the brains of hCSF1Bdes mice without triggering a NK-driven immune response. Furthermore,we confirmed the multipronged response of microglia in the context of Alzheimer’s disease. The hCSF1Bdes and the crosses with the Alzheimer’s disease knock-in model AppSAA and the humanized App knock-in control mice,AppHu are deposited with EMMA and fully accessible to the research community.ConclusionThe hCSF1Bdes mouse is available for both non-profit and for-profit organisations,facilitating the use of the xenotransplantation paradigm for human microglia to study complex human disease.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13024-025-00823-2. View Publication

A fundamental impediment to understanding the brain is the availability of inexpensive and robust methods for targeting and manipulating specific neuronal populations. The need to overcome this barrier is pressing because there are considerable anatomical,physiological,cognitive and behavioral differences between mice and higher mammalian species in which it is difficult to specifically target and manipulate genetically defined functional cell types. In particular,it is unclear the degree to which insights from mouse models can shed light on the neural mechanisms that mediate cognitive functions in higher species,including humans. Here we describe a novel recombinant adeno-associated virus that restricts gene expression to GABAergic interneurons within the telencephalon. We demonstrate that the viral expression is specific and robust,allowing for morphological visualization,activity monitoring and functional manipulation of interneurons in both mice and non-genetically tractable species,thus opening the possibility to study GABAergic function in virtually any vertebrate species. View Publication

Early cognitive deficits in Alzheimer's disease (AD) seem to be correlated to dysregulation of glutamate receptors evoked by amyloid-beta (Aβ) peptide. Aβ interference with the activity of N-methyl-d-aspartate receptors (NMDARs) may be a relevant factor for Aβ-induced mitochondrial toxicity and neuronal dysfunction. To evaluate the role of mitochondria in NMDARs activation mediated by Aβ,we followed in situ single-cell simultaneous measurement of cytosolic free Ca(2+)(Cai(2+)) and mitochondrial membrane potential in primary cortical neurons. Our results show that direct exposure to Aβ + NMDA largely increased Cai(2+) and induced immediate mitochondrial depolarization,compared with Aβ or NMDA alone. Mitochondrial depolarization induced by rotenone strongly inhibited the rise in Cai(2+) evoked by Aβ or NMDA,suggesting that mitochondria control Ca(2+) entry through NMDARs. However,incubation with rotenone did not preclude mitochondrial Ca(2+) (mitCa(2+)) retention in cells treated with Aβ. Aβ-induced Cai(2+) and mitCa(2+) rise were inhibited by ifenprodil,an antagonist of GluN2B-containing NMDARs. Exposure to Aβ + NMDA further evoked a higher mitCa(2+) retention,which was ameliorated in GluN2B(-/-) cortical neurons,largely implicating the involvement of this NMDAR subunit. Moreover,pharmacologic inhibition of endoplasmic reticulum (ER) inositol-1,4,5-triphosphate receptor (IP3R) and mitCa(2+) uniporter (MCU) evidenced that Aβ + NMDA-induced mitCa(2+) rise involves ER Ca(2+) release through IP3R and mitochondrial entry by the MCU. Altogether,data highlight mitCa(2+) dyshomeostasis and subsequent dysfunction as mechanisms relevant for early neuronal dysfunction in AD linked to Aβ-mediated GluN2B-composed NMDARs activation. View Publication

SummaryMesenchymal stromal cells (MSCs) have been modified via genetic or pharmacological engineering into potent antigen-presenting cells-like capable of priming responding CD8 T cells. In this study,our screening of a variant library of Accum molecule revealed a molecule (A1) capable of eliciting antigen cross-presentation properties in MSCs. A1-reprogrammed MSCs (ARM) exhibited improved soluble antigen uptake and processing. Our comprehensive analysis,encompassing cross-presentation assays and molecular profiling,among other cellular investigations,elucidated A1’s impact on endosomal escape,reactive oxygen species production,and cytokine secretion. By evaluating ARM-based cellular vaccine in mouse models of lymphoma and melanoma,we observe significant therapeutic potency,particularly in allogeneic setting and in combination with anti-PD-1 immune checkpoint inhibitor. Overall,this study introduces a strong target for developing an antigen-adaptable vaccination platform,capable of synergizing with immune checkpoint blockers to trigger tumor regression,supporting further investigation of ARMs as an effective and versatile anti-cancer vaccine. Graphical abstract Highlights•Treatment with A1/antigen mix reprograms MSCs into antigen-presenting cells•The antigen cross-presenting ability of ARM cells require ROS and UPR•ARMs synergize with immune-checkpoint inhibitors in priming potent antitumoral activity Classification Description: Immunology; Pharmaceutical engineering; Cancer View Publication