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Systematic discovery of pathogen effector functions across human pathogens and pathways.

Pathogens deploy effector proteins to exploit host cell biology, and most effector open reading frames (ORFs) are rapidly evolving and lack functional annotation. We developed the effector ORFeome (eORFeome), a scalable functional genomics platform encompassing 3,835 effector ORFs from diverse viruses, bacteria, and parasites. High-throughput barcoded screens across nuclear factor κB (NF-κB), apoptosis, p53, cGAS-STING, and major histocompatibility complex class I (MHC class I) pathways revealed novel pathway-modulating functions for hundreds of uncharacterized eORFs, unexpected activities of known effectors, and distinct pathway-specific functions encoded by single ORFs. Illustrating the power of this approach, we identified HHV6A U14 as a p53 antagonist, HHV7 U21 as a dual-function STING antagonist and MHC-I antigen display inhibitor, and adenoviral 13.6K/i-leader protein as a de novo-evolved TAP inhibitor that suppresses MHC-I display. These results establish a general framework for systematic effector annotation, uncover new mechanisms of host-pathogen interaction across kingdoms, and highlight pathogen effectors as a versatile toolkit for rewiring and probing human cellular pathways.

Humans

Peptide ligands targeting GP64 for the purification of Baculovirus from insect cell lysates.

Autographa californica multiple nucleopolyhedrovirus, known as Baculovirus, is a widely used platform for producing therapeutic proteins and viral vectors. The purity and infectious activity of Baculovirus stocks determine the quality and productivity of recombinant products produced through this system. Current purification strategies suffer from major limitations: centrifugation lacks productivity and scalability; ion-exchange chromatography affords limited selectivity and purity; and the only commercial affinity resin requires harsh elution conditions that significantly reduce functional product recovery. To overcome these limitations, this study introduces the first peptide affinity ligands targeting the baculoviral envelope glycoprotein GP64 for the purification of active Baculovirus particles. We implemented a combinatorial selection workflow based on dual-fluorescence screening of solid-phase peptide libraries to identify 12-mer sequences that bind GP64 and elute Baculovirus under mild conditions (pH 8.5). As the selected ligands are enriched in histidine and tyrosine residues, product release is effected by the combined modulation of pH and ionic strength. Eight candidate peptides (SB1-SB8) were evaluated on Toyopearl and POROS chromatographic resins, demonstrating that matrix chemistry, pore size, and ligand density govern purification performance. The lead peptide SB4 conjugated to POROS resin at ∼10 µmol/mL achieved 81% recovery of infectious virions (transducing units), robust host cell protein reduction (LRV 1.65), and a dynamic binding capacity (DBC10%) of 1.9 × 1010 vg/mL resin. Transmission electron microscopy and multi-angle light scattering confirmed the integrity of purified particles (200 × 50 nm rods with intact nucleocapsids), compared to BacuClear eluates that showed collapsed morphology. The SB4-POROS resin demonstrated storage stability and ∼80% retention of binding capacity over ten purification-regeneration cycles with caustic cleaning. Integration into a three-step downstream process (clarification, affinity capture, and polishing) raised product purity 1,528-fold, from 6.22 × 106 to 9.50 × 109 viral genomes per µg of HCP, while reducing the total HCP burden 1,698-fold, at a cumulative transducing-unit yield of ∼69% relative to the feedstock, establishing SB4-POROS as a promising technology with a favorable projected cost structure for Baculovirus purification.

Affinity chromatography

Suppression of AAV-Delivered Transgene Expression Using Artificial MicroRNAs Delivered by an Alternative AAV Serotype.

Adeno-associated virus (AAV) gene transfer vectors mediate long-term expression in nondividing cells, an advantage for treating chronic disorders. However, current platforms lack a way to selectively shut down transgene expression if adverse effects arise. To create an "off switch," we hypothesized that incorporating unique artificial microRNA (amiRNA) target sequences into an AAV expression cassette would allow subsequent suppression of transgene expression using a second AAV vector encoding the cognate amiRNA. We introduced 22-nt sequences absent from human and mouse transcriptomes into the 3' untranslated region (UTR) of a therapeutic AAV cassette. To identify optimal amiRNAs, two tandem copies of each amiRNA were cloned into the 3'UTR of an mCherry reporter gene. In vitro assessment of six amiRNA/target pairs using a dual luciferase assay identified four amiRNAs that efficiently suppressed reporter expression. Cells cotransfected with target site 3 (TS3) and amiRNA-T3B showed the greatest reduction in luciferase activity (80%, p < 0.0001) and were selected for further study. The "off-switch" system was then evaluated using an AAV5 therapeutic vector expressing a recombinant humanized anti-IgE monoclonal antibody (AAV5-TBG-anti-IgE-TS3), designed for long-term suppression of allergen-induced reactions. Co-transfection of HEK293T cells with anti-IgE-TS3 and amiRNA-T3B significantly reduced anti-IgE mRNA and protein levels relative to a control amiRNA (p < 0.0001). In vivo testing in Balb/c mice (n = 5) involved intravenous administration of AAV5-anti-IgE-TS3 (3.2 &#xd7; 1010 gc), followed 4 weeks later by an AAVrh.10 amiRNA vector (AAVrh.10-TBG-amiRNA-T3B; 1 &#xd7; 1011 gc). Control mice receiving only the therapeutic vector expressed 18.4 &#xb1; 13.8 &#xb5;g/mL serum anti-IgE at 10 weeks. In contrast, mice receiving the amiRNA "off" vector showed marked suppression of anti-IgE (0.3 &#xb1; 0.15 &#xb5;g/mL, p < 0.0001). These findings provide proof-of-concept that AAV-delivered amiRNAs can selectively switch off transgene expression, offering a strategy to improve the safety of AAV-mediated gene therapies.

Dependovirus

Near-Infrared Fluorescent PROTAC Enables Theranostic Imaging and Selective Tau Degradation in Alzheimer's Disease.

The hyperphosphorylated Tau (p-Tau) protein plays a central role in the pathogenesis of Alzheimer's disease (AD) by driving neurofibrillary tangle formation and neuronal dysfunction. While proteolysis targeting chimeras (PROTACs) offer a promising approach for directly eliminating pathogenic proteins, their real-time visualization in living systems remains challenging. Here, we report the rational design and synthesis of a series of near-infrared (NIR) fluorescent Tau-targeting degraders that integrate theranostic imaging with targeted protein degradation. Among them, compound D9 emerges as a dual-functional degrader capable of both high-contrast fluorescence tracking and potent Tau clearance at 10&#xa0;nM. Mechanistic investigations indicate that D9 induces Tau degradation through activation of the ubiquitin-proteasome system (UPS), as confirmed by inhibitor assays. Beyond Tau degradation, D9 also downregulates amyloid precursor protein (APP) and &#x3b2;-amyloid (A&#x3b2;) expression, suggesting broader neuroprotective effects. In in vivo studies, D9 significantly promotes p-Tau clearance and alleviates cognitive deficits in 3 &#xd7;Tg-AD mice. These findings demonstrate that D9 represents a first-in-class NIR fluorescent PROTAC for theranostic imaging and targeted degradation of Tau, providing a powerful platform for visualizing degradation dynamics and developing next-generation AD therapeutics.

Alzheimer's disease

Development of a highly efficient prime editing platform for cucurbits enables breeding of multi-disease-resistant cucumber.

The prime editing (PE) system is a precise genome editing technology that works efficiently in monocots; however, its application is limited by low editing efficiency in dicots, particularly Cucurbitaceae and Solanaceae plants. Here, we first significantly improved the transformation efficiency by introducing spectinomycin in cucurbits, then used the tomato elongation factor 1-alpha (SlEF1&#x3b1;) promoter to enhance PE protein expression, and incorporated the Csy4 ribonuclease to process pegRNAs, collectively addressing multiple constraints limiting PE efficiency in cucurbits. The optimized PE systems, particularly Csy4-PE6d, achieved an average desired editing frequency of 80.83% at targeted loci in cucumber via stable genetic transformation, with frequencies reaching up to 100% at certain sites. Moreover, Csy4-PE6d generated homozygous edits in 36.43% of transgenic lines and demonstrated robust editing activity in melon, pumpkin, and potato. Using the Csy4-PE6d tool, we generated heritable edited cucumber lines with dual resistance to bacterial angular leaf spot and downy mildew by targeting the CsSGR gene. Collectively, this optimized system substantially enhances PE efficiency in Cucurbit crops, providing an effective solution to common challenges such as low editing efficiency and limited heritability in these species.

Disease Resistance

Enhancing and accelerating cell type deconvolution of large-scale spatial transcriptomics slices with dual network model.

MOTIVATION: Cell type deconvolution deciphers spatial distribution of mRNA transcripts at single cell level by integrating single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics data to infer mixture of cell types of spots in slices. Current algorithms are criticized for neglecting connection between scRNA-seq and spatial transcriptomics data, as well as time-consuming, hampering their application to large-scale datasets. RESULTS: In this study, we propose a joint learning nonnegative matrix factorization algorithm for fast cell type deconvolution (aka jMF2D), which integrates scRNA-seq and spatial transcriptomics data with network models. To bridge scRNA-seq and spatial transcriptomics data, jMF2D jointly learns cell type similarity network to enhance quality of signatures of cell types, thereby promoting accuracy and efficiency of deconvolution. Experiments demonstrate that jMF2D outperforms state-of-the-art baselines in terms of accuracy by saving about 90% running time on various datasets generated by different platforms. Furthermore, it can also facilitates the identification of spatial domains and bio-marker genes, providing an efficient and effective model for analyzing spatial transcriptomics data. AVAILABILITY AND IMPLEMENTATION: The software is coded using python, and is free available for academic https://github.com/xkmaxidian/jMF2D.

Algorithms

Reprogrammed Komagataella phaffii for enhanced secretory expression of human lactoferrin.

Human lactoferrin (hLF) is a multifunctional glycoprotein of the transferrin family derived from milk and mucosal secretions, which exhibits antibacterial, anti-tumor, and immunomodulatory functions, and is an important component of infant formula. Conventional methods for lactoferrin expression are often inefficient, primarily due to inadequate protein synthesis capabilities and poor stability within microbial hosts. Herein, a Komagataella phaffii yeast strain capable of high-level secretory expression of hLF was constructed by reprogramming the endoplasmic reticulum (ER) and vacuole using CRISPR/Cas9 technology. A dual-expression cassette containing the AOX1 promoter, an &#x3b1;-secretion signal peptide, the hLF gene, and a terminator was integrated into three different sites of the K. phaffii genome. The stepwise strategy combining expansion of the ER membrane involved in protein synthesis with knockout of vacuolar proteases further enhanced hLF production. Subsequently, 0.1&#x202f;g/L FeCl&#x2083; was added to the medium to reduce the toxicity of hLF and improve its stability. After high-density cultivation of K. phaffii through optimization of cultivation conditions in shake flasks and a 5&#x202f;L bioreactor, the secretory intact hLF titer reached 2214&#x202f;mg/L, representing a 76.3-fold increase achieved through these engineering strategies. In addition, antibacterial experiments demonstrated that this secretory hLF had a significant inhibitory effect on Escherichia coli, Staphylococcus aureus, and yeast. Overall, the developed K. phaffii protein expression platform enabled efficient production of lactoferrin, demonstrating its potential for expressing other lactoproteins.

Lactoferrin

Comprehensive profiling of activity and specificity of RNA-guided transposons reveals opportunities to engineer improved variants.

Recently discovered CRISPR-associated transposons (CASTs) are natural RNA-guided DNA transposition systems capable of single-step genomic integration of large DNA cargo. Wild-type CASTs exhibit low integration activity in heterologous systems; therefore, engineering efforts are required to develop therapeutically relevant tools. Here we developed a high-throughput dual genetic screen capable of accurately quantifying the relative activity and specificity of a large pool of CAST variants. Under the conditions of our screen, we discovered that the wild-type V-K CAST system can consistently achieve between 88% and&#xa0;95% on-site targeting specificity. We used site-saturation mutagenesis of the conserved core transposition machinery (TnsB, TnsC, and TniQ) to reveal novel mechanistic insights into the function of these transposon proteins. Furthermore, we found that different components have varying trade-offs between activity and specificity, a critical aspect overlooked in conventional screening pipelines. These findings provide clear engineering principles for further optimization of CASTs. Finally, we identified several mutations that, together, enhance CAST activity up to four-fold while minimally impacting targeting specificity. These methods are a powerful tool to characterize the sequence-function landscape across multiple functional parameters while also providing a robust platform for developing enhanced genome-editing tools.

DNA Transposable Elements

GLP-1 Receptor Agonists and Musculoskeletal Outcomes: A Systematic Literature Review and Meta-Analysis.

INTRODUCTION: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used for the treatment of type 2 diabetes and obesity, but their effects on musculoskeletal health remain completely misunderstood. OBJECTIVE: This systematic review/meta-analysis aims to synthesise clinical data on the effects of GLP-1 RAs on key relevant bone, muscle, and joint outcomes. METHODS: MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) (both via Ovid&#xae; platform) and Embase were searched from inception to March 2025 to identify relevant randomised controlled trials (RCTs) or real-world evidence (RWE) studies to be included. This bibliographic search was completed manually. A random-effect model meta-analysis was performed for any outcome reported in at least 2 studies. Subgroup analyses were performed on the type of GLP-1 RAs, type of comparator used and study design. Sensitivity analyses (i.e., leave-out sensitivity analyses and analyses restricted to the most adjusted effect estimate) were performed to test the robustness of the data. The strength of evidence was assessed using GRADE. This work has been performed in adherence with PRISMA statement. (PROSPERO Record ID: CRD420251024082). RESULTS: From 1148 potentially relevant references, 60 articles (46 RCTs, 13 RWE studies and 1 pharmacovigilance study, comprising 1,250,717 individuals) met our inclusion criteria. Different GLP-1 RAs were represented across the panel of studies, i.e., semaglutide, liraglutide, exenatide, dulaglutide, tirzepatide (dual agonist gastric inhibitory polypeptide [GIP]/GLP-1) and others. No effect on bone outcomes (i.e., bone mineral density [all sites] and fractures [all sites]) were observed when the meta-analytical models included the most adjusted effect size. Regarding muscle outcomes, a significant decrease of lean body mass/fat-free mass was consistently observed with GLP-1 RAs in the global model (k = 28, standardised mean difference [SMD] 0.52, 95% confidence interval [CI] -0.8; -0.23, I2 88%, p-value for heterogeneity <0.0001), which remained robust in all sensitivity analyses. Subgroup analyses showed that the effect was mainly driven by liraglutide and semaglutide, with a decrease in lean body mass/fat-free mass observed when GLP-1 RAs were compared with placebo. No publication bias was found. Regarding joint outcome, models revealed no significant change in The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, physical function and stiffness. CONCLUSIONS: This meta-analysis is the first to investigate the effects of GLP-1 RAs on a large panel of musculoskeletal health outcomes. While no significant effects were observed on bone- or joint-related outcomes, GLP-1 RAs were associated with reductions in lean body mass/fat-free mass, although the certainty of evidence was low and these changes appeared largely related to weight loss. Whether these changes translate into clinically meaningful impairments in muscle function or physical performance remains uncertain. Further studies in this field, including those looking at muscle function, strength or performance and using multivariate models considering confounding are needed to better reinforce the models and final findings.

Journal Article

Dual-patterned pluripotent stem cells self-organize into a human embryo model with extended anterior-posterior patterning.

Human gastruloids are a powerful class of stem cell-derived models that recapitulate key features of early embryonic development, including symmetry breaking and the emergence of three germ layers1-3. However, they lack anterior embryonic structures and coordinated axial organization4-6. To address this limitation, we pre-patterned human pluripotent stem cells (hPSCs) by exposing them to either anterior (FGF2) or posterior (CHIR99021 [CHIR] & retinoic acid [RA]) cues. Upon mixing, these dual-patterned hPSCs interacted and self-organized into elongated structures with both anterior and posterior features-which we term anterior-posterior (AP) human gastruloids. Anteriorly pre-treated cells robustly intercalated into posteriorly pre-treated cells, collectively giving rise to a continuum of neural tissues-including a brain-like domain, a neural tube-like structure, and neuro-mesodermal progenitors (NMPs)-with segmented somites arrayed bilaterally. Single cell RNA sequencing (scRNA-seq) revealed that human AP gastruloids contain cell types resembling the midbrain-hindbrain boundary (MHB), regionalized hindbrain structures (i .e. rhombomeres 1-8), regionalized neural crest (i.e. cranial, vagal, trunk)7,8 and head mesoderm. Transcriptomic comparisons to primate embryos revealed that human AP gastruloids most closely resemble Carnegie stage 11 (CS11) embryos. While they lack a notochord and full dorsal-ventral polarity, human AP gastruloids recapitulate key spatial and temporal features of early neurulation and somitogenesis. Perturbation of folic acid metabolism or rho-associated kinase (ROCK) signaling induced spinal cord defects, phenocopying aspects of spina bifida and other neural tube defects, highlighting this model's potential for studying congenital disorders9. AP gastruloids may serve as a simple, robust, scalable platform for modeling coordinated human AP body axis development. More broadly, our results suggest that controlled interactions between differentially prepatterned progenitors can initiate self-organization of complex body axis features. The "pattern-and-mix" strategy may serve as a generalizable framework for assembling spatially organized stem cell models of mammalian development.

Journal Article

Manual, digital, and AI tumour-infiltrating lymphocyte scoring: a secondary analysis of the APHINITY randomised trial.

BACKGROUND: Stromal tumour-infiltrating lymphocytes (sTILs) are prognostic in early-stage HER2-positive breast cancer, but their role in the context of dual HER2 blockade remains undefined. We evaluated manual, digital, and artificial intelligence (AI)-based sTIL quantification, together with AI-derived spatial metrics, for prognostic and treatment-benefit stratification using tumour samples from the phase 3 APHINITY trial. METHODS: In the APHINITY trial, 4805 patients were randomly assigned to receive chemotherapy plus trastuzumab with pertuzumab or chemotherapy plus trastuzumab with placebo. Median follow-up was 74&#xb7;1 months (IQR 68&#xb7;3-75&#xb7;4). We analysed 4262 haematoxylin and eosin-stained images using manual assessment, an automated digital approach, AI-based lymphocyte quantification (AI percentage lymphocytes), and two AI-derived spatial features (AI-TIL and immune hotspot). Interobserver reproducibility was assessed in 262 randomly chosen tumour samples scored independently by five pathologists. Multivariable Cox models were used to assess associations between TIL levels and invasive disease-free survival (primary outcome in APHINITY), distant recurrence-free interval, and overall survival. The heterogeneity of pertuzumab benefit was evaluated using subgroup analyses, subpopulation treatment effect pattern plot analyses, and nested Cox models with treatment-by-biomarker interaction terms. FINDINGS: Manual scoring showed high interobserver reproducibility (intraclass correlation coefficient 0&#xb7;84 [95% CI 0&#xb7;79-0&#xb7;88]). Concordance between manual and automated methods was modest. AI-based scoring (AI percentage lymphocytes) reclassified 120 (11&#xb7;6%) of 1035 node-positive tumours from immune-low (by manual scoring) to immune-high; this subgroup of patients showed greater separation of 5-year invasive disease-free survival curves between pertuzumab and placebo groups compared with patients whose tumours were concordantly classified as immune-low by both manual and AI-based approaches. Higher levels of TILs were associated with improved invasive disease-free survival for all sTIL measurement approaches and spatial measurements (hazard ratios [HRs] 0&#xb7;41-0&#xb7;93). Pertuzumab was associated with improved invasive disease-free survival at higher sTIL levels across all measurement approaches (HRs 0&#xb7;36-0&#xb7;48), but was not associated with higher values of spatial measures. The largest 6-year absolute improvements with pertuzumab were observed in patients with node-positive disease whose tumours scored in the highest level of immune infiltration of manual sTIL scoring (&#x2265;70&#xb7;0%; mean absolute improvement 12&#xb7;1 percentage points [SD 2&#xb7;8]). In nested prognostic and predictive models, AI-based immune hotspot scores provided the most consistent additional information when combined with any sTIL measurement (all p<0&#xb7;010). INTERPRETATION: Standardised manual sTIL scoring was reproducible, and digital and AI-based methods showed consistent prognostic stratification and potential for treatment-benefit stratification despite only modest correlation between platforms. AI spatial metrics provided complementary information beyond sTIL density and could support more scalable immune assessment. Future studies are needed to validate these approaches in independent cohorts and to clarify their clinical utility for stratifying contemporary HER2-directed therapies. FUNDING: None.

Humans