bioRxiv Science⌕ Search

Biology subjects

Wang, L.

Publications and source records attributed to Wang, L..

At least 289 records · Page 16Linked to original sources

AI Identifies Broadly Neutralizing Antibodies from an IGHV1-69 Public Antibody Class Exerting Continued Selection Over SARS-CoV-2

R1-32-like public antibodies, characterized by shared IGHV1-69/IGLV1-40 usage, are elicited in more than 50% of individuals with COVID-19 and have been implicated in driving recurrent mutations at L452SARS2 and F490SARS2 within their convergent epitope in the SARS-CoV-2 spike receptor-binding domain. These mutations effectively mediate escape from non-affinity-matured R1-32-like antibodies with germline-like sequences. Here, we characterize four affinity-matured R1-32-like antibodies, C092, C807, BD56-104, and BD56-597, that tolerate L452SARS2 and F490SARS2 mutations. We show that this tolerance arises from residues introduced by somatic hypermutation at convergent positions across multiple CDR loops and surrounding regions, thereby creating additional contacts that reinforce epitope binding. An unusual N354SARS2 glycosylation site, which emerged in BA.2.86 and became fixed in its descendants, is linked to escape from affinity-matured R1-32-like antibodies, implying ongoing selection by this public antibody class. Using an AI model trained on integrated structural, neutralization, and binding data, we further identified ZL525, an ultrapotent R1-32-like antibody with pan-SARS-CoV-2 variant activity, including against the highly evasive KP.3 variant carrying the N354SARS2 glycosylation, and broad sarbecovirus cross-reactivity extending to SARS-CoV-1. Together, these findings show how affinity maturation enables public antibodies to adapt to viral antigenic drift, reveal their role in shaping SARS-CoV-2 antigenic evolution, and demonstrate the potential of AI-empowered strategies for discovering broadly neutralizing antibodies.

immunology↗

Batch Effects Remain a Fundamental Barrier to Universal Embeddings in Single-Cell Foundation Models

Constructing a cell universe requires integrating heterogeneous single-cell RNA-seq datasets, but is hindered by diverse batch effects. Single-cell foundation models (scFMs), inspired by large language models, aim to learn universal cellular embeddings from large-scale single-cell data. However, unlike language, single-cell data are sparse, noisy, and strongly affected by batch effects that limit cross-dataset transferability. Our systematic evaluation across diverse batch scenarios reveals that current scFMs fail to effectively remove batch effects, with batch signals persisting in pretrained embeddings. Post-hoc batch-centering partially improves alignment, highlighting the need for future scFMs to integrate explicit batch-effect correction mechanisms to achieve true universal cellular embeddings.

bioinformatics↗

DINOcell: Learning Generalizable Perturbation Effects through Self-Distillation

AO_SCPLOWBSTRACTC_SCPLOWPredicting cellular responses to therapeutics is a promising approach for novel target discovery. However, state-of-the-art computational models designed to predict perturbation effects struggle to generalize and outperform simple baselines. We present DINOcell, a weakly supervised framework that adapts self-distillation to single-cell transcriptomics for predicting perturbation effects. We demonstrate that DINOcell outperforms baselines in predicting the effects of single gene perturbations. Furthermore, DINOcell accurately predicts non-additive effects of combination perturbations, indicating its capacity to model complex genetic interactions. Finally, we show that DINOcell learns representations that capture biological signals and is a promising, generalizable approach for in silico perturbation modeling, providing a valuable tool for accelerating therapeutic target discovery.

bioinformatics↗

Comprehensive perturbation of transcription factors in human cardiomyocytes reveals the regulatory architecture of congenital heart disease

Transcription factors (TFs), including DNA binding proteins and epigenetic co-regulators, control the timing of gene programs during lineage commitment1. However, systematically defining the dynamic activities of the human genomes nearly 2000 TFs during development remains challenging2,3. Here, we use Perturb-Seq to map the transcriptional impact of nearly all human TFs and a subset of enhancers during cardiomyocyte differentiation. Our results suggest that developmental regulatory networks are distributed across highly connected hub TFs4-6 that are dynamic across lineage and time, rather than organizing into top-down hierarchies directed by "master regulators". We also identify distinct TF ensembles that regulate sequential decision points during cardiac cell-fate specification by coordinating lineage-specific activation with alternate lineage repression. Separately, analysis of TF-TF cooperativity uncovers a dynamic interaction between MEF2 family TFs7 and members of the Polycomb Repressive complex 18-10 to execute alternative fate repression. Building on these regulatory interactions, we construct a deep learning transformer model to accurately predict perturbed TFs driving altered regulatory networks in patient-derived transcriptomes. Together, our results define the regulatory network architecture of human lineage specification and provide a platform for predicting TF function and interpreting disease mechanisms.

genomics↗

High-Coverage Jomon Genomes Provide Insights into Population Structure and Genetic Traits of Ancient Japanese Hunter-Gatherers

We analyzed eight high-coverage Jomon genomes spanning 9,000-2,800 years ago across the Japanese archipelago. Population genomic analyses revealed substantial genetic homogeneity across time and space reflecting post-glacial isolation, yet temporal stratification emerged: Initial Jomon (Iyai) individuals formed the earliest branch with weaker affinities to present-day Japanese. Using genomes from Todoroki and Chidorikubo sites, we estimated Jomon ancestry in mainland Japanese at [~]20%, substantially higher than previous estimates ([~]13%). Polygenic score analyses, based on the direct analysis of Jomon genomes, provided the genetic evidence for their phenotypic predispositions, including elevated BMI and metabolic trait scores, reduced immune-related scores, and larger cardiac dimensions, patterns consistent with hunter-gatherer adaptations. These ancestral genetic influences, including elevated risks for obesity and dyslipidemia, persist in present-day Japanese. Our findings demonstrate that Jomon populations maintained genetic continuity despite ecological diversity, while their greater-than-expected contribution to present-day Japanese reshapes population history models and reveals how ancient adaptations continue influencing contemporary disease susceptibility.

genomics↗

Confinement prevents postmenopausal osteoporosis and obesity via nuclear mechanical remodeling

Postmenopausal osteoporosis (PMOP), affecting about half of postmenopausal women, is a major global health burden characterized by fragile bones and frequent comorbidity with obesity. Bone marrow mesenchymal stem cells (BMSCs) differentiation imbalance underpins PMOP pathogenesis and represents an attractive therapeutic target. Here, we demonstrate mechanically confining BMSCs to soft substrates mimicking physiological bone marrow stiffness completely suppresses adipogenic differentiation while inducing osteogenic differentiation. Mechanistically, confinement-induced elevation of nuclear envelope tension upregulates Lamin A/C expression, which in turn modulates Runx2 nuclear localization by activating histone acetylation via KAT2B, thereby directing BMSCs osteogenesis. Remarkably, FDA-approved deacetylation inhibitor Chidamide significantly enhances bone regeneration while concurrently suppressing obesity in a PMOP animal model, highlighting the significant therapeutic potential of nuclear mechanotransduction as a target for PMOP and obesity treatment. This work not only provides new insights into the mechanical regulation of bone homeostasis but also opens new avenues for the treatment of osteoporosis-related disorders.

biophysics↗

Optimization of AAV tools to target Muller glial cells for retinal gene therapy

Reprogramming of Muller glial (MG) cells into retinal neurons has the potential to treat vision loss by regenerating the retina. Development of efficient gene delivery systems to target the MG cells is critical. Adeno-associated virus (AAV) serotypes and promoter specificity are important factors that influence AAV transduction profile in the retina. However, studies that optimize these parameters to specifically target MG cells are limited, in particular in rats which are commonly used for eye research. Here we tested 4 AAV serotypes and 14 promoters to optimize gene delivery to human MG cells in vitro and/or rat MG cells in vivo. We showed that the combinatorial use of MG-specific serotypes and promoters achieved high specificity for MG cell targeting, with ShH10Y serotype and the GFAP (gfaABC1D) promoter as the best performing tool to target rat MG cells in vivo. We developed new AAV vectors using known and novel MG-specific promoters and engineered short promoter variants to improve the cargo capacity of AAV delivery. Our results highlighted a number of promoters that can target MG cells in vitro or in vivo. This study further expands the AAV toolbox to target MG cells, which has important implications for retinal gene therapy development.

molecular biology↗

Cryogenic 3D electron microscopy captures whole plant cell native ultrastructure

Volume electron microscopy (vEM) provides nanometer-scale, three-dimensional imaging of cells, but applying it to plant systems remains challenging. Cell walls, large vacuoles, and tissue thickness complicate sample preparation and cryogenic imaging. Here we report a cryogenic vEM (cryo-vEM) workflow for unstained plant protoplasts that achieves volumetric imaging of whole vitrified sorghum stem protoplasts without chemical fixation, dehydration, resin embedding, or heavy-metal staining. The method integrates optimized protoplast isolation, plunge-freezing vitrification for native-state preservation, automated cryogenic focus ion beam scanning electron microscopy (cryo-FIB-SEM) slice-and-view acquisition, contrast enhancement and stack alignment, and AI-assisted human-in-the-loop 3D segmentation. Using sorghum stem protoplasts as a demonstration, the workflow captured large-volume frozen-hydrated protoplast ultrastructure, allowing visualization of major organelles, including the nucleus, mitochondria, vacuoles, ER/Golgi-like membranes, lipid bodies, and subcellular features consistent with nuclear-envelope pores. We further quantified organelle volumes and surface areas from the segmented 3D data, highlighting the potential for quantitative cellular ultrastructure analysis. This cryo-vEM workflow provides a platform for near-native structural studies of isolated plant protoplasts.

plant biology↗

Alignment of Artificial Neural Networks with Human Eye Movement Patterns in Facial Expression Recognition

Artificial neural networks (ANNs) have become powerful tools for modeling human perception and hehavior, yet it remains unclear if they resemble the sequential eye movement strategies humans employ during visual processing. Human studies demonstrate that the first two fixations play distinct roles in face processing: the initial fixation (Fix I) captures global configurational information, while the second (Fix II) targets local diagnostic details, with the two working collaboratively to support recognition. In this study, we tested if such properties emerge in ANNs trained for facial expression recognition. We fine-tuned a convolutional neural network (VGG16) and a Vision Transformer (ViT) on multiple facial expression datasets and evaluated their performance on the same images used in a human eye-tracking experiment. Human participants (N = 28) achieved a mean accuracy of 84.2%, VGG reached 82.9%, and ViT outperformed both at 90.0%. Perturbation analyses showed that both models aligned with the independent functions of Fix I and Fix II, but only ViT displayed a synergistic effect when information from both fixations was combined. Layer-wise analyses revealed stronger correspondence with Fix II than Fix I in both models, while ViT uniquely captured the statistical dependencies of fixation transitions. These findings suggest that VGG primarily reflects feedforward, detail-based processing, whereas ViT supports feedback-like integration across sequential fixations. Our results indicate that current ANNs can approximate human eye movement patterns in face processing, and highlight the potential of transformer-based architectures to model sequential strategies in human visual exploration.

neuroscience↗

Satellite microglia gate neuronal excitability by shielding inhibitory synapses in adult brain

Microglia, the primary immune cells of the central nervous system, are known for sculpting excitatory neural circuits via dynamic processes. However, their role in modulating inhibitory synaptic connections in adulthood remains largely unexplored. In this study, we identified an underappreciated microglia subpopulation, satellite microglia with physical soma-soma contact with neurons, that reshape inhibitory circuit connectivity and gate neuronal activity by shielding inhibitory synapses in the adult mouse brain. Using chronic in vivo two-photon imaging in adult mice, we observed in real time that satellite microglia associations displaced perisomatic inhibitory synapses whereas their dissociation permitted inhibitory synaptogenesis. Redistribution of satellite microglia reorganized inhibitory connectivity, altered local neural networks and changed behaviors. These findings establish satellite microglia as key architects of inhibitory circuitry and suggest their broader role in neural plasticity in health and disease.

neuroscience↗

Synchronized Latency Reversal and Immune Clearance by a Multifunctional Fusion Protein Enables HIV-1 Reservoir Reduction

Strategies that concurrently reactivate latent reservoirs and enhance immune-mediated clearance hold significant promise for achieving an HIV cure. Here, we developed hyperIL-15xsCD4-Fc (15xsCD4-Fc), a fusion protein that integrates latency reactivation, targeted immune engagement, and effector-mediated killing into a single molecule. This agent not only potently reverses HIV-1 latency in CD4+ T cells from people living with HIV-1 (PLWH) through coordinated IL-15 receptor signaling and sCD4-mediated HIV-1 envelope (Env) engagement, but also enhances antigen-specific CD8+ T cell response in PBMCs derived from PLWH. Furthermore, 15xsCD4-Fc enables Env-specific elimination of reactivated latently infected cells by NK cells while preventing off-target cytotoxicity. In PBMCs from PLWH, 15xsCD4-Fc reduced replication-competent HIV-1 DNA by 93.8%. In antiretroviral treated HIV-1-infected humanized mice, the molecule demonstrated both safety and efficacy in diminishing viral reservoir in lymphoid organs. This spatiotemporally coupled approach to reservoir exposure and immune recognition establishes a clinically viable strategy for clearing the HIV-1 reservoir. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=195 SRC="FIGDIR/small/693434v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@8f8f0org.highwire.dtl.DTLVardef@10f63f7org.highwire.dtl.DTLVardef@16c1de2org.highwire.dtl.DTLVardef@11e1787_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Detection of CRISPR-Cas-induced mutations in Daphnia

CRISPR-Cas9 has established itself as a robust tool for conducting loss of function gene research in emerging model species including the freshwater zooplankton Daphnia. However, sensitive detection of mutations, especially in genetic mosaic and pooled samples, remains a challenge. In this study we evaluate two of the most widely used mutation screening techniques, the T7 Endonuclease I (T7EI) assay and Fragment Analysis (FA) for their sensitivity, accuracy, and practical use in detecting CRISPR-induced indels in four targeted genes, DNMT3A, DNMT3B, PERIOD2, and DMRT1 in Daphnia magna. Here, we show that T7EI, although it offers a quick and cost-effective screening method, often produces false positives, especially when examining pooled samples. Conversely, FA facilitates detecting allele size differences at a fine resolution, reproducibility in detecting indels, and distinguishing zygosity and is more reliable as a method to detect mutation. Our comparative analyses convey the importance of carefully selecting the appropriate screening methods depending on research questions.

genetics↗

Human stem cell models for group 3 medulloblastoma uncover JARID1B as a regulator of the chromatin landscape.

Medulloblastoma (MB) is one of the most prevalent malignant brain tumors in children, with tremendous cognitive and neuroendocrine disability among survivors. Group 3 MB (G3MB) has poor overall survival at <50%, high frequencies of metastases, and no targeted therapies. Amplification of MYC and activation of TGF{beta} signaling occur frequently in G3MB. Many tumors have no reported mutations, suggesting epigenetic drivers. We here describe novel humanized models for G3MB from human induced pluripotent stem cells (hiPSC). By transducing hiPSC-derived neuroepithelial stem cells (NESC), we determined that: 1) both MYC and TGF{beta} effectors drove tumors in vivo; 2) MYC/TGF{beta}R1 in combination led to more aggressive tumors and resistance to clinical inhibitors of TGF{beta}, and 3) NESC-derived tumors clustered with human G3MB. To decipher mechanisms, we integrated RNA-sequencing with CUT&RUN (for MYC genomic localization and post-translational modification of histones). MYC-bound neural developmental genes were repressed in MYC/TGF{beta}R1 co-driven lines. Gene signatures associated with the Polycomb Repressive Complex (PRC) demarcated with H3K27me3; the histone mark directly regulated by PRC. We identified JARID1B, a MYC binding partner and H3K4me3 demethylase, as a regulator of repressed neural genes. Primary G3MB also showed increased levels of H3K27me3 concurrent with higher expression of JARID1B. Knockdown of JARID1B in human G3MB cell lines reduced growth, supporting potential as a therapeutic target. We conclude that a MYC-TGF{beta}-JARID1B axis represses target genes to drive G3MB and present new humanized models for G3MB to understand epigenetic dysregulation in G3MB.

cancer biology↗

RBM15 promotes lung adenocarcinoma progression and palbociclib sensitivity via m6A-mediated STIL activation and downstream cyclin D1/CDK4 signaling

RNA-binding motif protein 15 (RBM15), an N6-methyladenosine (m6A) methyltransferase, plays a crucial role in the progression of lung adenocarcinoma (LUAD); however, the underlying mechanisms remain insufficiently defined. In this study, we investigated the contribution of RBM15-mediated m6A modification to LUAD pathogenesis. Our data showed that RBM15 was highly expressed in LUAD tissues and cell lines. Notably, its expression levels were positively correlated with tumor TNM staging and negatively correlated with differentiation status. The overexpression of RBM15 enhanced cell proliferation, migration, invasion, and cell cycle progression, while simultaneously inhibiting apoptosis. Conversely, RBM15 knockdown reversed these phenotypes and induced G2/M-phase arrest. In vivo experiments further confirmed that RBM15 knockdown led to the suppression of tumor growth. RNA sequencing, MeRIP sequencing, and bioinformatics analyses identified STIL as a gene directly regulated by RBM15 through m6A modification, a finding subsequently validated by luciferase reporter assays. Western blot and rescue experiments demonstrated that RBM15 and STIL cooperatively activate the cyclin D1/CDK4 signaling pathway, thereby promoting LUAD progression. However, this effect was markedly attenuated by CDK4/6 inhibitor application. Collectively, these findings indicated that the RBM15-STIL-cyclin D1/CDK4 axis represents a promising therapeutic target for LUAD.

cancer biology↗

Dynamic alterations of DNA methylation and transcriptome in adaptation to and recovery from the space environment

Space exploration presents tremendous health challenges. Here, we report time series of multi-omic and phenotypic profiles of seventeen astronauts from six China Manned Space missions with continuous spaceflight durations ranging from 13 to 180 days. We revealed a key role of DNA methylation regulation in reshaping gene expression patterns to adapt to the space environment. Long-duration spaceflight showed more alterations in epigenetic modifications correlated with alternative splicing and protein acetylation. During recovery, an "overrange rebound" phenomenon was observed, furthermore, a mathematical model was established to describe this implying important phenomenon. Moreover, we revealed the correlations between molecular alterations and phenotypic changes such as coagulation activation and bone intensity loss. Additionally, we performed ground-based simulation experiments to estimate the impacts of individual stressors in the space environment on DNA methylation. In summary, our study highlights the importance and complexity of epigenetic regulation in adaptation to and recovery from the space environment.

genomics↗

The Human Hippocampus Is Involved in Auditory Short-Term Memory Trace Formation

The human hippocampus has been claimed to play an important role in long-term memory, or episodic memory, but its contribution to short-term memory remains debated. Here, we demonstrate human hippocampal involvement in auditory short-term memory (ASTM) trace formation. We used a classic oddball paradigm and intracranial recordings across various human brain areas. High frequency activities evoked by deviant stimuli in subjects indicate the generation of ASTM trace. Analysis of auditory response latencies across the hippocampus, insula, and temporal, parietal, and frontal lobes revealed the early processing of ASTM trace at a pre-attention stage. Granger causality analysis further showed that ASTM trace processing engages hierarchical cortical areas and clarified their interactions. Bottom-up signals flow from the insula and auditory temporal regions to the frontal lobe early on, followed by top-down information from the frontal lobe to the hippocampus, inferior temporal lobe, and insula at a later pre-attentive stage. Critically, Bayesian model selection of dynamic causal modeling revealed that deviant stimuli selectively enhanced the effectiveness of top-down connections to the hippocampus, thereby facilitating ASTM trace formation. These results provide compelling evidence that the human hippocampus contributes to auditory short-term memory at a pre-attention stage and suggests a challenge to entrenched beliefs in the classification of memory systems.

neuroscience↗

Gut microbe-derived short-chain fatty acids regulate joint inflammation and activation of infiltrating and resident myeloid cells after alphavirus infection

Although oral antibiotics can predispose to joint inflammation, this phenomenon remains poorly understood. Here, we leverage mouse models of alphavirus-induced arthritis to investigate the roles of gut commensals, metabolites, and host immune mechanisms in promoting musculoskeletal inflammation. Mice treated with a short course of oral antibiotics exhibited worsened arthritis after chikungunya (CHIKV) or Mayaro virus infections. This phenotype was associated with loss of short chain fatty acids (SCFA), greater intestinal permeability, and activation of gut-associated immune cells, and required TLR4 signaling, MyD88 expression, monocytes, antigen-specific and bystander CD4+ T cells, and pro-inflammatory cytokines. Administration of exogenous SCFA or colonization of mice with bacterial species that generate SCFA mitigated CHIKV-induced joint inflammation. Single-cell RNA sequencing revealed that gut-derived SCFA ameliorate the inflammatory phenotype of synovial CD4+ T cells, infiltrating monocytes, and resident osteoclast-like cells. Thus, antibiotic-triggered gut dysbiosis exacerbates alphavirus arthritis by shaping the inflammatory profile of both infiltrating and resident immune cells in joint tissues.

immunology↗

PKU tags, novel genetically encoded shape tags for cell labeling in light and electron microscopy

Distinguishing among neuronal cell types is crucial for deciphering complex neural networks and brain functions. However, the current repertoire of cell-labeling tools compatible with light microscopy (LM) and/or electron microscopy (EM) is limited compared to the vast number of cell types in the brain. Here, we introduce PKU (polymer king-size unit) tags, genetically encoded "shape tags" that leverage the polymerization of self-assembling proteins, spectrally distinct fluorescent proteins and, optionally, a nuclear targeting sequence to generate a series of multi-shaped (spherical or filamentous), multi-colored (blue, green, red, near-infrared) and multi-localized (cytosolic or nuclear) tags. By co-expressing multiple PKU tags within the same cell, a combinatorial strategy further expands the repertoire, which can theoretically yield hundreds of unique labeling patterns. Expressing PKU tags in vivo provides multi-cell-type labeling and neuronal circuit tracing, without altering the animals behavior or transcriptomic profiles. Moreover, when fused to the peroxidase APEX2, PKU tags maintain their shape-specific features, providing shape "barcoding" using EM. Thus, PKU tags represent a versatile and efficient toolkit for studying connectomics using both LM and EM.

neuroscience↗