技术资料

Autoantibodies targeting cytosolic 5′-nucleotidase 1A (cN1A) are found in several autoimmune diseases,including inclusion body myositis (IBM),Sjögren’s syndrome,and systemic lupus erythematosus. While they have diagnostic relevance for IBM,little is known about the autoreactive B cells that produce these antibodies. To address this,we developed a robust protocol for the expression and site-specific biotinylation of recombinant human cN1A in Escherichia coli. The resulting antigen is suitable for generating double-labelled fluorescent baits for the isolation and characterisation of cN1A-specific B cells by flow cytometry. Site-specific biotinylation was achieved using the AviTag and BirA ligase,preserving the protein’s structure and immunoreactivity. Western blot analysis confirmed that the biotinylated cN1A was recognised by both human and rabbit anti-cN1A antibodies. Compared to conventional chemical biotinylation,this strategy minimises structural alterations that may affect antigen recognition. This approach provides a reliable method for producing biotinylated antigens for use in immunological assays. While demonstrated here for cN1A,the protocol can be adapted for other autoantigens to support studies of antigen-specific B cells in autoimmune diseases. View Publication

The ovary is one of the first organs to exhibit signs of aging,characterized by reduced tissue function,chronic inflammation,and fibrosis. Multinucleated giant cells (MNGCs),formed by macrophage fusion,typically occur in chronic immune pathologies,including infectious and non-infectious granulomas and the foreign body response,but are also observed in the aging ovary. The function and consequence of ovarian MNGCs remain unknown as their biological activity is highly context-dependent,and their large size has limited their isolation and analysis through technologies such as single-cell RNA sequencing. In this study,we define ovarian MNGCs through a deep analysis of their presence across age and species using advanced imaging technologies as well as their unique transcriptome using laser capture microdissection. MNGCs form complex interconnected networks that increase with age in both mouse and nonhuman primate ovaries. MNGCs are characterized by high Gpnmb expression,a putative marker of ovarian and non-ovarian MNGCs. Pathway analysis highlighted functions in apoptotic cell clearance,lipid metabolism,proteolysis,immune processes,and increased oxidative phosphorylation and antioxidant activity. Thus,MNGCs have signatures related to degradative processes,immune function,and high metabolic activity. These processes were enriched in MNGCs compared to primary ovarian macrophages,suggesting discrete functionality. MNGCs express CD4 and colocalize with T-cells,which were enriched in regions of MNGCs,indicative of a close interaction between these immune cell types. These findings implicate MNGCs in modulation of the ovarian immune landscape during aging given their high penetrance and unique molecular signature that supports degradative and immune functions. Ovarian multinucleated giant cells are a unique macrophage population that arise within the aging mammalian ovary. This study characterizes their transcriptome in mice,uncovering a potential role in degradation of cellular debris and immune signaling,suggesting a potential contribution to ovarian inflammation during aging. View Publication

Post-transplant complications reduce allograft and recipient survival. Current approaches for detecting allograft injury non-invasively are limited and do not differentiate between cellular mechanisms. Here,we monitor cellular damages after liver transplants from cell-free DNA (cfDNA) fragments released from dying cells into the circulation. We analyzed 130 blood samples collected from 44 patients at different time points after transplant. Sequence-based methylation of cfDNA fragments were mapped to an atlas of cell-type-specific DNA methylation patterns derived from 476 methylomes of purified cells. For liver cell types,DNA methylation patterns and multi-omic data integration show distinct enrichment in open chromatin and functionally important regulatory regions. We find that multi-tissue cellular damages post-transplant recover in patients without allograft injury during the first post-operative week. However,sustained elevation of hepatocyte and biliary epithelial cfDNA within the first month indicates early-onset allograft injury. Further,cfDNA composition differentiates amongst causes of allograft injury indicating the potential for non-invasive monitoring and intervention. Current approaches to detect allograft damages non-invasively are limited and do not differentiate between cellular mechanisms. Here,the authors show that the composition of cell-free DNA in blood samples can reveal cellular causes of allograft injury after liver transplant. View Publication

AbstractObjectiveNatural killer (NK) cells are the largest innate lymphocyte subset with potent antitumour and antiviral functions. However,clinical utilisation of human NK cells is hampered due to a lack of reliable methods to augment their antitumour potential. We demonstrated technology in which human NK cells were cocultured with osteoclasts in the presence of probiotic bacteria. This approach significantly augmented the antitumour cytotoxicity and polyfunctionality of human NK cells,resulting in the generation of supercharged NK (sNK) cells.Methods and analysisWe explored the proteomic,transcriptomic and functional characterisation of sNK cells using cell imaging,flow cytometric analysis,51-chromium release cytotoxicity assay,ELISA,ELIspot,IsoPLexis single-cell secretome analysis,proteomic analysis,RNA analysis,western blot and enzyme kinetics.ResultsWe found that sNK cells were less susceptible to split anergy and tumour-induced exhaustion. Proteomic analyses revealed that sNK cells significantly increased their cell motility and proliferation. Single-cell transcriptomes uncovered sNK cells undertaking a unique differentiation trajectory and turning on STAT1,JUN,BHLHE40,ELF1,MAX and MYC regulons essential for augmenting antitumour effector functions and proliferation,respectively. Both proteomic and single-cell transcriptomes revealed that an increase in Cathepsin C helped to augment the quantity and function of Granzyme B.ConclusionsThese results support that this unique method produces potent NK cells for clinical utilisation and delineate the molecular mechanisms associated with this process. View Publication

Zhang et al. demonstrate that the expression of a mutated CARMIL2 protein in CD28-deficient mice induces most of the developmental and functional consequences known to result from CD28 costimulation and in turn triggers potent tumor-specific T cell responses resistant to PD-1 and CTLA-4 blockade. Naive T cell activation requires both TCR and CD28 signals. The CARMIL2 cytosolic protein enables CD28-dependent activation of the NF-κB transcription factor via its ability to link CD28 to the CARD11 adaptor protein. Here,we developed mice expressing a mutation named Carmil2QE and mimicking a mutation found in human T cell malignancies. Naive T cells from Carmil2QE mice contained preformed CARMIL2QE-CARD11 complexes in numbers comparable to those assembling in wild-type T cells after CD28 engagement. Such ready-made CARMIL2QE-CARD11 complexes also formed in CD28-deficient mice where they unexpectedly induced most of the functions that normally result from CD28 engagement in a manner that remains antigen-dependent. In turn,tumor-specific T cells expressing Carmil2QE do not require CD28 engagement and thereby escape to both PD-1 and CTLA-4 inhibition. In conclusion,we uncovered the overarching role played by CARMIL2-CARD11 signals among those triggered by CD28 and exploited them to induce potent solid tumor–specific T cell responses in the absence of CD28 ligands and immune checkpoint inhibitors. View Publication

Non-viral DNA donor templates are commonly used for targeted genomic integration via homologous recombination (HR),with efficiency improved by CRISPR/Cas9 technology. Circular single-stranded DNA (cssDNA) has been used as a genome engineering catalyst (GATALYST) for efficient and safe gene knock-in. Here,we introduce enGager,an enhanced GATALYST associated genome editor system that increases transgene integration efficiency by tethering cssDNA donors to nuclear-localized Cas9 fused with single-stranded DNA binding peptide motifs. This approach further improves targeted integration and expression of reporter genes at multiple genomic loci in various cell types,showing up to 6-fold higher efficiency compared to unfused Cas9,especially for large transgenes in primary cells. Notably,enGager enables efficient integration of a chimeric antigen receptor (CAR) transgene in 33% of primary human T cells,enhancing anti-tumor functionality. This ‘tripartite editor with ssDNA optimized genome engineering (TESOGENASE) offers a safer,more efficient alternative to viral vectors for therapeutic gene modification. Non-viral DNA donor templates are commonly used for targeted genomic integration via homologous recombination. Here the authors present the TESOGENASE system which enhances CRISPR-based gene integration by tethering circular single-stranded DNA to Cas9. View Publication

AbstractBackgroundNatural killer (NK) cells’ unique ability to kill transformed cells expressing stress ligands or lacking major histocompatibility complexes (MHC) has prompted their development for immunotherapy. However,NK cells have demonstrated only moderate responses against cancer in clinical trials.MethodsAdvanced genome engineering may thus be used to unlock their full potential. Multiplex genome editing with CRISPR/Cas9 base editors (BEs) has been used to enhance T cell function and has already entered clinical trials but has not been reported in human NK cells. Here,we report the first application of BE in primary NK cells to achieve both loss-of-function and gain-of-function mutations.ResultsWe observed highly efficient single and multiplex base editing,resulting in significantly enhanced NK cell function in vitro and in vivo. Next,we combined multiplex BE with non-viral TcBuster transposon-based integration to generate interleukin-15 armored CD19 chimeric antigen receptor (CAR)-NK cells with significantly improved functionality in a highly suppressive model of Burkitt’s lymphoma both in vitro and in vivo.ConclusionsThe use of concomitant non-viral transposon engineering with multiplex base editing thus represents a highly versatile and efficient platform to generate CAR-NK products for cell-based immunotherapy and affords the flexibility to tailor multiple gene edits to maximize the effectiveness of the therapy for the cancer type being treated. View Publication

Tetracyclines are essential bacterial protein synthesis inhibitors under continual development to combat antibiotic resistance yet suffer from unwanted side effects. Mitoribosomes - responsible for generating oxidative phosphorylation (OXPHOS) subunits - share structural similarities with bacterial machinery and may suffer from cross-reactivity. Since lymphocytes rely upon OXPHOS upregulation to establish immunity,we set out to assess the impact of ribosome-targeting antibiotics on human T cells. We find tigecycline,a third-generation tetracycline,to be the most cytotoxic compound tested. In vitro,5–10 μM tigecycline inhibits mitochondrial but not cytosolic translation,mitochondrial complex I,III and IV expression,and curtails the activation and expansion of unique T cell subsets. By cryo-EM,we find tigecycline to occupy three sites on T cell mitoribosomes. In addition to the conserved A-site found in bacteria,tigecycline also attaches to the peptidyl transferase center of the large subunit. Furthermore,a third,distinct binding site on the large subunit,aligns with helices analogous to those in bacteria,albeit lacking methylation in humans. The data provide a mechanism to explain part of the anti-inflammatory effects of these drugs and inform antibiotic design. Tetracyclines impair cellular function by targeting ribosomes. Here,the authors demonstrate that tigecycline impairs T cell function by selectively inhibiting mitochondrial protein synthesis and uncover the structural basis for mitoribosome inhibition and its role in immunosuppression. View Publication

Extracellular DNA (eDNA) is crucial for the structural integrity of bacterial biofilms as they undergo transformation from B-DNA to Z-DNA as the biofilm matures. This transition to Z-DNA increases biofilm rigidity and prevents binding by canonical B-DNA-binding proteins,including nucleases. One of the primary defenses against bacterial infections are Neutrophil Extracellular Traps (NETs),wherein neutrophils release their own eDNA to trap and kill bacteria. Here we show that H-NS,a bacterial nucleoid associated protein (NAP) that is also released during biofilm development,is able to incapacitate NETs. Indeed,when exposed to human derived neutrophils,H-NS prevented the formation of NETs and lead to NET eDNA retraction in previously formed NETs. NETs that were exposed to H-NS also lost their ability to kill free-living bacteria which made H-NS an attractive therapeutic candidate for the control of NET-related human diseases. A model of H-NS release from biofilms and NET incapacitation is discussed. View Publication

Myocardial infarction (MI) is a major global health concern. Although myeloid cells are crucial for tissue repair in emergency haematopoiesis after MI,excessive myelopoiesis can exacerbate scarring and impair cardiac function. Bone marrow (BM) haematopoietic stem cells (HSCs) have the unique capability to replenish the haematopoietic system,but their role in emergency haematopoiesis after MI has not yet been established. Here we collected human sternal BM samples from over 150 cardiac surgery patients,selecting 49 with preserved cardiac function. We show that MI causes detrimental transcriptional and functional changes in human BM HSCs. Lineage tracing experiments suggest that HSCs are contributors of pro-inflammatory myeloid cells infiltrating cardiac tissue after MI. Therapeutically,enforcing HSC quiescence with the vitamin A metabolite 4-oxo-retinoic acid dampens inflammatory myelopoiesis,thereby modulating tissue remodelling and preserving long-term cardiac function after MI. Rettkowski,Romero-Mulero et al. show that myocardial infarction impacts bone marrow haematopoietic stem cells and leads to inflammatory myelopoiesis,which can be dampened by treatment with 4-oxo-retinoic acid,promoting cardiac recovery. View Publication

AbstractBackgroundChimeric antigen receptor (CAR) T-cell therapy depends on T cells that are genetically modified to recognize and attack cancer cells. Their effectiveness thus hinges on the functionality of a patient’s own T cells. Since CAR T-cell therapy is currently only approved for advanced cancers after at least one line of chemotherapy,we evaluated the potential negative effects of prior exposure to chemotherapy on T-cell functionality.MethodsWe studied T cells of two B-cell non-Hodgkin’s lymphoma patient cohorts,one collected before treatment (pre-therapy) and the other after one or more (median 3) lines of chemotherapy (post-therapy). Leveraging advanced multiparameter flow cytometry,single-cell RNA sequencing (scRNA-seq),whole-genome DNA methylation arrays and in vitro functionality testing of generated CAR T cells,we compared patient samples in their suitability for effective CAR T-cell therapy.ResultsWe discovered significant modifications in T-cell subsets and their transcriptional profiles secondary to chemotherapy exposure. Our analysis revealed a discernible shift towards phenotypically more differentiated T cells and an upregulation of markers indicative of T-cell exhaustion. Additionally,scRNA-seq and DNA methylation analyses revealed gene expression and epigenetic changes associated with diminished functionality in post-therapy T cells. Cytotoxicity assays demonstrated superior killing efficacy of CAR T cells derived from treatment-naïve patients compared with those with chemotherapy history.ConclusionsThese findings corroborate that employing T cells collected prior to frontline chemotherapy could enhance the effectiveness of CAR T-cell therapy and improve patient outcomes. View Publication

AbstractThere is currently a lack of tools capable of perturbing genes in both a precise and a spatiotemporal fashion. The flexibility of CRISPR (clustered regularly interspaced short palindromic repeats),coupled with light’s unparalleled spatiotemporal resolution deliverable from a controllable source,makes optogenetic CRISPR a well-suited solution for precise spatiotemporal gene perturbations. Here,we present a new optogenetic CRISPR tool (Blue Light-inducible Universal VPR-Improved Production of RGRs,BLU-VIPR) that diverges from prevailing split-Cas design strategies and instead focuses on optogenetic regulation of guide RNA (gRNA) production. We engineered BLU-VIPR around a new potent blue-light activated transcription factor (VPR-EL222) and ribozyme-flanked gRNA. The BLU-VIPR design is genetically encoded and ensures precise excision of multiple gRNAs from a single messenger RNA transcript. This simplified spatiotemporal gene perturbation and allowed for several types of optogenetic CRISPR,including indels,CRISPRa,and base editing. BLU-VIPR also worked in vivo with cells previously intractable to optogenetic gene editing,achieving optogenetic gene editing in T lymphocytes in vivo. Graphical Abstract Graphical Abstract View Publication