Biology subjects

Fan, J.

Publications and source records attributed to Fan, J..

At least 73 records · Page 4Linked to original sources

bioRxiv2025

Cell cycle-coupled transcriptional network orchestrates human B cell fate bifurcation

Bifurcation of activated human B cells into plasmablast (PB) and germinal center precursor (preGC) fates underlies protective and autoimmune antibody responses, yet gene regulatory networks (GRNs) governing the alternative trajectories remain poorly defined. Using temporal single-cell multiomics, we assembled state-specific human B cell GRNs spanning four scales: transcription factor (TF)-to-fate, TF-to-gene, cis-regulatory element (CRE)-to-gene and nucleotide-to-CRE. Applying the framework to in vitro differentiated and tonsil B cells revealed concordant regulatory architectures and impacts of in silico TF perturbations. CRISPR perturbations validated many TF-to-fate and TF-to-gene predictions and revealed a mutually repressive BATF-IRF4/PRDM1 network module. The GRNs were used to predict and interpret effects of autoimmune disease variants, uncovering partitioning of disease risk at distinct TF motifs and B cell states. Predicted functional variants were independently supported by chromatin and expression QTLs and reporter assays. A web application enables exploration of B cell regulatory determinants of vaccine responses and autoimmune diseases.

immunology↗

bioRxiv2025

Molecular insights into early malignant transition of hepatocellular carcinoma

The molecular continuum of premalignant-to-malignant transition remains elusive in carcinogenesis, primarily due to the difficulty in sampling transitional lesions. Here, we present comprehensive genomic and immunological profiling of 21 very early hepatocellular carcinomas (veHCCs) arising within 17 cancer-prone DNs. Surprisingly, 82% of cancer-prone DNs harbored TERT alterations, suggesting a predisposing rather than causative role in malignancy transition. A substantial increase in CNA burden, rather than SNV, was noted, indicating a role of chromosome instability in malignancy transition. Additionally, veHCC-originating DNs showed immune inactivity, not falling into the prevailing paradigm that HCCs develop in a context of chronic inflammation. 43% of veHCCs showed an inflamed phenotype with relatively mild CNA burden but already exhibited immune evasion features. Two major evolutionary scenarios were thus proposed: 1) CNA-dominant progression and 2) early immune evasion of those with mild CNA burden. Collectively, our findings illustrate previously unexplored molecular paradigms in HCC initiation, highlighting the therapeutic potential of immunotherapy for early intervention.

cancer biology↗

bioRxiv2025

Functional MRI Signatures of Autonomic Physiology in Aging

While traditionally regarded as "noise", blood-oxygenation-level-dependent (BOLD) fMRI fluctuations coupled to systemic physiology--such as heart rate and respiratory changes--also hold valuable information about brain vascular properties and autonomic function. In this study, we leverage these physiological BOLD signals to characterize age-related changes in brain physiology. Using a large dataset from the Lifespan Human Connectome Project Aging study, we investigated how the spatiotemporal BOLD-fMRI signatures of autonomic physiology, specifically heart rate and respiratory variation, change with advancing age. Our findings reveal that aging is associated with globally slower respiratory fMRI responses, alongside faster cardiac fMRI responses and enhanced brain-cardiac signal coupling. Moreover, we show that the impact of age on physiological fMRI signals exhibits a notable turning point after age 60, suggesting a critical role of declining vascular health and autonomic function in aging. The potential impact of age-related changes in brain structure, tissue perfusion, and in-scan arousal states on the identified physiological fMRI patterns is also tested and discussed. Altogether, our results underscore significant age effects in the fMRI signatures of systemic physiology, emphasizing the pivotal role of altered vascular properties and autonomic function in aging. Methodologically, this study also demonstrates the utility of resting-state fMRI for extracting multi-parametric information about brain physiology, offering new biomarker opportunities that complement established functional connectivity metrics.

physiology↗

bioRxiv2025

TUCL-Seq for miRNA single molecule sequencing

MicroRNAs (miRNAs) are pivotal regulatory molecules in gene expression, and their precise quantification is essential for elucidating their roles in diverse biological processes. This research paper introduces a pioneering workflow for the single molecule sequencing (SMS) of miRNA, integrating advanced miRNA sample preparation with SMS sequencing. Central to our approach is TUCL-Seq, which is an automated, on-chip miRNA library preparation method designed to streamline the sequencing process. This innovative approach incorporates the addition of sequencing adaptor to RNA samples in solution, and converts it to cDNA on a sequencing flow cell for sequencing. Coupled with single molecule sequencing instrument and base-call software, our workflow significantly reduces sample-to-result time, and decreases the need for manual interventions compared to traditional SMS and next-generation sequencing methods. We demonstrate the efficacy of TUCL-Seq by accurately quantifying synthetic miRNA samples with a 24-hour workflow, showcasing its potential for high-throughput miRNA profiling. Our findings highlight the promise of this integrated workflow for advancing miRNA research and applications in diagnostics and therapeutics.

biochemistry↗

bioRxiv2025

Evidence of off-target probe binding in the 10x Genomics Xenium v1 Human Breast Gene Expression Panel compromises accuracy of spatial transcriptomic profiling

The accuracy of spatial gene expression profiles generated by probe-based in situ spatially-resolved transcriptomic technologies depends on the specificity with which probes bind to their intended target gene. Off-target binding, defined as a probe binding to something other than the target gene, can distort a genes true expression profile, making probe specificity essential for reliable transcriptomics. Here, we investigated off-target binding affecting the 10x Genomics Xenium technology. We developed a software tool, Off-target Probe Tracker (OPT), to identify putative off-target binding via alignment of probe sequences and assessing whether mapped loci corresponded to the intended target gene across multiple reference annotations. Applying OPT to a Xenium human breast gene panel, we identified at least 14 out of the 313 genes in the panel potentially impacted by off-target binding to protein-coding genes. To substantiate our predictions, we leveraged a Xenium breast cancer dataset generated using this gene panel and compared results to orthogonal spatial and single-cell transcriptomic profiles from Visium CytAssist and 3' single-cell RNA-seq derived from the same tumor block. Our findings indicate that for some genes, the expression patterns detected by Xenium demonstrably reflect the aggregate expression of the target and predicted off-target genes based on Visium and single-cell RNA-seq rather than the target gene alone. We further applied OPT to identify potential off-target binding in custom gene panels and integrate tissue-specific RNA-seq data to assess effects. Overall, this work enhances the biological interpretability of spatial transcriptomics data and improves reproducibility in spatial transcriptomics research.

bioinformatics↗

bioRxiv2025

Protocol for Extracting Circulating Cell-Free DNA from Murine Saliva: Insights into Oral and Systemic Disease Research

Circulating cell-free DNA (cfDNA) consists of small fragments of extracellular DNA from mammalian and bacterial cells found in bodily fluids such as blood and saliva, and it has been strongly recognized as a critical biomarker for various disease diagnoses, prognoses, and therapeutic monitoring. In this study, we present a reproducible protocol for efficiently isolating cfDNA from murine saliva using an innovative swabbing method in conjunction with the QIAamp MinElute ccfDNA Mini Kit. The quantification of isolated cfDNA is detected by a Qubit Fluorometer. Moreover, qualification assessment is conducted through BioAnalyzer analysis. This protocol facilitates research on saliva-derived cfDNA in the context of oral and systemic diseases in murine models. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/645839v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@19ce903org.highwire.dtl.DTLVardef@85fa20org.highwire.dtl.DTLVardef@1e869eaorg.highwire.dtl.DTLVardef@181c340_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

bioRxiv2025

Genomic and Transcriptomic Signatures of SETD1A Disruption in Human Excitatory Neuron Development and Psychiatric Disease Risk

Genetic disruption of SETD1A markedly increases the risk for schizophrenia. To elucidate the underlying mechanisms, we generated isogenic organoid models of the developing human cerebral cortex harboring a SETD1A loss-of-function schizophrenia risk mutation. Employing chromatin profiling combined with RNA sequencing, we identified high-confidence SETD1A target genes, analyzed the impact of the mutation on SETD1A binding and transcriptional regulation and validated key findings with orthogonal approaches. Disruption of SETD1A function disturbs the finely tuned temporal gene expression in the excitatory neuron lineage, yielding an aberrant transcriptional program that compromises key regulatory and metabolic pathways essential for neurodevelopmental transitions. Although overall SETD1A binding remains unchanged in mutant neurons, we identified localized alterations in SETD1A binding that correlate with shifts in H3K4me3 levels and gene expression. These changes are enriched at enhancer regions, suggesting that enhancer-regulated genes are especially vulnerable to SETD1A reduction. Notably, target genes with enhancer-bound SETD1A are primarily linked to neuronal functions while those with promoter-bound SETD1A are enriched for basic cellular functions. By mapping the SETD1A binding landscape in excitatory neurons of the human fetal frontal cortex and integrating multimodal neuroimaging and genetic datasets, we demonstrate that the genomic context of SETD1A binding differentially correlates with macroscale brain organization and establish a link between SETD1A-bound enhancers, schizophrenia-associated brain alterations and genetic susceptibility. Our study advances our understanding of the role of SETD1A binding patterns in schizophrenia pathogenesis, offering insights that may guide future therapeutic strategies.

neuroscience↗

bioRxiv2025

High-throughput, unbiased single-molecule displacement mapping with deep learning reveals spatiotemporal heterogeneities in intracellular diffusivity

Single-molecule displacement/diffusivity mapping (SMdM) has revolutionized the study of molecular motion in live cells by providing high spatial resolution insights. However, its utility is restricted by measurement biases and low throughput, making it challenging to capture temporal dynamics of intracellular diffusivity. Here we report a high-throughput single-molecule diffusivity microscopy approach (Hi-SMdM) that rapidly and unbiasedly maps nanoscale heterogeneities in molecular motion inside mammalian cells, enabling time-resolved imaging of local diffusivity dynamics. Hi-SMdM employs a self-supervised deep-learning denoising framework with a general noise model to effectively restore the scarce signals of fast-moving single molecules, while eliminating artifact motions without relying on spatial redundancies or temporal correlations. It then provides unbiased estimations of nanoscale diffusion coefficient and improve both throughput and temporal resolution by up to an order of magnitude. We demonstrate the versatility of Hi-SMdM through time-resolved mapping of the spatially heterogeneous diffusivity of free proteins in the cytoplasm. Hi-SMdM also unveils the temporal dynamics of intracellular diffusion under hypotonic conditions in live cells. Additionally, Hi-SMdM tracks the spatiotemporal dynamics of intraorganellar diffusivity during rapid rearrangements of the ER network and functional activities of mitochondria. Overall, Hi-SMdM provides exceptional opportunities for high-throughput and unbiased single-molecule diffusivity mapping with excellent spatiotemporal resolution.

biophysics↗

bioRxiv2025

Microglia regulate neuronal activity via structural remodeling of astrocytes

Neuron-glia interactions play a central role in regulating synaptic transmission and neuronal excitability. Structural plasticity of astrocytes is associated with numerous physiological and pathological conditions, however, the mechanism underlying this process remains unknown. To examine the basis for structural astrocyte plasticity, we used the classic example of the loss of astrocytic processes that takes place in the hypothalamic magnocellular system during chronic high-salt intake. We discovered that a high-salt diet triggers a local accumulation of reactive microglia around vasopressin-secreting neurons, but not in other brain areas. Microglia phagocytose astrocytic processes, reducing astrocytic coverage of vasopressin neurons. The pruning of astrocytic processes impairs synaptic glutamate clearance, enabling activation of extrasynaptic glutamate NMDA receptors and increasing the activity of vasopressin neurons. Inhibiting microglia-mediated astrocyte pruning attenuates the increased neuronal activity and vasopressin-dependent hypertensive phenotype of rats fed high-salt diet. Thus, microglia orchestrate neuron-glia interactions and regulate neuronal activity through astrocyte pruning.

neuroscience↗

bioRxiv2025

Tissue reassembly with generative AI

The spatial arrangement of cells is fundamental to their function, but single-cell RNA sequencing loses spatial context by dissociating cells from tissues. We present LUNA, a generative AI model that reassembles dissociated cells into tissue structures solely from gene expression by learning spatial priors from existing spatially resolved datasets. We apply and validate LUNA across multiple technologies including reconstructing the MERFISH whole mouse brain atlas with over 1.2 million cells, de novo reassembly of mouse central nervous system scRNA-seq atlas and inference of the spatial locations of nuclei lost during Slide-tags profiling. Furthermore, we show that LUNA generalizes to unseen cell types and to pathological samples in the Parkinsons disease mouse model, identifying regions of change due to pathology. We envision that AI-driven tissue reassembly can help to overcome current technological limitations and advance our understanding of tissue organization and function.

bioinformatics↗

bioRxiv2025

Mitochondrial metabolism is rapidly re-activated in mature neutrophils to support stimulation-induced response

Neutrophils are highly abundant innate immune cells that are constantly produced from myeloid progenitors in the bone marrow. Differentiated neutrophils can perform an arsenal of effector functions critical for host defense. This study aims to quantitatively understand neutrophil mitochondrial metabolism throughout differentiation and activation, and to elucidate the impact of mitochondrial metabolism on neutrophil functions. To study metabolic remodeling throughout neutrophil differentiation, murine ER-Hoxb8 myeloid progenitor-derived neutrophils and human induced pluripotent stem cell-derived neutrophils were assessed as models. To study the metabolic remodeling upon neutrophil activation, differentiated ER-Hoxb8 neutrophils and primary human neutrophils were activated with various stimuli, including ionomycin, MSU crystals, and PMA. Characterization of cellular metabolism by isotopic tracing, extracellular flux analysis, metabolomics, and fluorescence-lifetime imaging microscopy revealed dynamic changes in mitochondrial metabolism. As neutrophils mature, mitochondrial metabolism decreases drastically, energy production is fully offloaded from oxidative phosphorylation, and glucose oxidation through TCA cycle is substantially reduced. Nonetheless, mature neutrophils retain the capacity for mitochondrial metabolism. Upon stimulation with certain stimuli, TCA cycle is rapidly activated. Mitochondrial pyruvate carrier inhibitors reduce this re-activation of the TCA cycle and inhibit the release of neutrophil extracellular traps. Mitochondrial metabolism also impacts neutrophil redox status, migration, and apoptosis without significantly changing overall bioenergetics. Together, these results demonstrate that mitochondrial metabolism is dynamically remodeled and plays a significant role in neutrophil function and fate. Furthermore, these findings point to the therapeutic potential of mitochondrial pyruvate carrier inhibitors in a range of conditions where dysregulated neutrophil response drives inflammation and contributes to pathology.

immunology↗

bioRxiv2025

Unsupervised multi-animal tracking for quantitative ethology

Quantitative ethology necessitates accurate tracking of animal locomotion, especially for population-level analyses involving multiple individuals. However, current methods rely on laborious annotations for supervised training and have restricted performance in challenging conditions. Here we present an unsupervised deep-learning method for multi-animal tracking (UDMT) that achieves state-of-the-art performance without requiring human annotations. By synergizing a bidirectional closed-loop tracking strategy, a spatiotemporal transformer network, and three sophisticatedly designed modules for localization refining, bidirectional ID correction, and automatic parameter tuning, UDMT can track multiple animals accurately in various challenging conditions, such as crowding, occlusion, rapid motion, low contrast, and cross-species experiments. We demonstrate the versatility of UDMT on five different kinds of model animals, including mice, rats, Drosophila, C. elegans, and Betta splendens. Combined with a head-mounted miniaturized microscope, we illustrate the power of UDMT for neuroethological interrogations to decipher the correlations between animal locomotion and neural activity. UDMT will facilitate advancements in ethology by providing a high-performance, annotation-free, and accessible tool for multi-animal tracking.

animal behavior and cognition↗

bioRxiv2025

Deficient Executive Control in Transformer Attention

Although transformers in the large language models (LLMs) effectively implement a self- attention mechanism that has revolutionized natural language processing, they lack an explicit implementation of executive control of attention found in humans, which is essential for resolving conflicts and selecting relevant information in the presence of competing stimuli, and is critical for adaptive behavior. To investigate this limitation in LLMs, we employed the classic color Stroop task that is widely regarded as the gold standard for testing executive control of attention. Our results revealed a typical conflict effect of better performance in terms of accuracy in the congruent condition (e.g., naming the ink color of the word RED in red) compared to the incongruent condition (e.g., naming the ink color of the word RED in blue), which is similar to human performance in short sequences. However, as sequence length increased, the performance degraded toward chance levels on the incongruent trials despite maintaining excellent performance on congruent trials and near-perfect word reading ability. These findings demonstrate that while transformer attention mechanisms can achieve human-comparable performance in smaller contexts, they are fundamentally limited in their capacity for conflict resolution across extended contexts. This study suggests that incorporating executive control mechanisms akin to those in biological attention could be crucial for achieving more general reasoning and reliable performance toward artificial general intelligence.

neuroscience↗

bioRxiv2025

Simultaneous EEG-PET-MRI identifies temporally coupled, spatially structured hemodynamic and metabolic dynamics across wakefulness and NREM sleep

Sleep entails significant changes in cerebral hemodynamics and metabolism. Yet, the way these processes evolve throughout wakefulness and sleep and their spatiotemporal dependence remain largely unknown. Here, by integrating a novel functional PET technique with simultaneous EEG-fMRI, we reveal a tightly coupled temporal progression of global hemodynamics and metabolism during the descent into NREM sleep, with large hemodynamic fluctuations emerging as global glucose metabolism declines, both of which track EEG arousal dynamics. Furthermore, we identify two distinct network patterns that emerge during NREM sleep: an oscillating, high-metabolism sensorimotor network remains active and dynamic, whereas hemodynamic and metabolic activity in the default-mode network is suppressed. These results elucidate how sleep diminishes awareness while preserving sensory responses, and uncover a complex, alternating balance of neuronal, hemodynamic, and metabolic dynamics in the sleeping brain. This work also demonstrates the potential of EEG-PET-MRI to explore neuro-hemo-metabolic dynamics underlying cognition and arousal in humans.

neuroscience↗

bioRxiv2025

Absolute Quantification of Aging-Associated Glycans in IgG for Biological Age Prediction: Insights from Glycomics and Transcriptomics

Immunoglobulin G (IgG) N-glycans have been identified as associated with aging; however, previous studies predominantly quantified changes based on the relative percentages of each glycan within the total glycan pool, neglecting the absolute concentration changes of individual glycans. Additionally, relative quantification can limit practical applications, as these often require absolute concentration measurements for consistent and interpretable biomarker values. In this study, we introduce a novel strategy for discovering aging-associated IgG glycans and establishing a prediction model based on their absolute concentration alteration. We employed a glycome quantification technology to identify the alteration in IgG glycan amount in natural aging and anti-aging (caloric restriction) models, discovering aging-related glycans. The glycomics analysis revealed key features: downregulation of bisected glycan GP3 (F(6)A2B) and upregulation of digalactosylated glycan GP8 (F(6)A2G2). These glycan changes showed significant fold changes from an early stage. Using external standards of these two glycans, we subsequently measured the absolute concentrations of them, allowing us to establish a predictive model, abGlycoAge, for biological aging. The abGlycoAge index suggested a younger state under caloric restriction, with an average age reduction of 3.9-14 weeks. Additionally, we performed RNA sequencing on splenic B cells of mice, suggesting Derl3, Smarcb1, Ankrd55, Tbkbp1 and Slc38a10 could contribute to the alteration of GP3 and GP8 in aging. This analysis enhances our understanding of glycan alterations, accounts for individual variability, and aids in designing effective anti-aging strategies. These findings highlight the crucial roles of the GP3 and GP8 as potential biomarkers for aging and health.

biochemistry↗

bioRxiv2024

Differentiating BOLD and non-BOLD signals in fMRI time series using cross-cortical depth delay patterns

Over the past two decades, rapid advancements in magnetic resonance technology have significantly enhanced the imaging resolution of functional Magnetic Resonance Imaging (fMRI), far surpassing its initial capabilities. Beyond mapping brain functional architecture at unprecedented scales, high-spatial-resolution acquisitions have also inspired and enabled several novel analytical strategies that can potentially improve the sensitivity and neuronal specificity of fMRI. With small voxels, one can sample from different levels of the vascular hierarchy within the cerebral cortex and resolve the temporal progression of hemodynamic changes from parenchymal to pial vessels. We propose that this characteristic pattern of temporal progression across cortical depths can aid in distinguishing neurogenic blood-oxygenation-level-dependent (BOLD) signals from typical nuisance factors arising from non-BOLD origins, such as head motion and pulsatility. In this study, we examine the feasibility of applying cross-cortical depth temporal lag (CortiLag) patterns to automatically categorize BOLD and non-BOLD signal components in modern-resolution BOLD-fMRI data. We construct an independent component analysis (ICA)-based framework for fMRI de-noising, analogous to previously proposed multi-echo (ME) ICA, except that here we explore the across-depth instead of across-echo dependence to distinguish BOLD and non-BOLD components. The efficacy of this framework is demonstrated using visual task data at three graded spatiotemporal resolutions (voxel sizes = 1.1, 1.5, and 2.0 mm isotropic at temporal intervals = 1700, 1120, and 928 ms). The proposed CortiLag-ICA framework leverages prior knowledge of the spatiotemporal properties of BOLD-fMRI and serves as an alternative to ME-ICA for cleaning moderate- and high-spatial-resolution fMRI data when multi-echo acquisitions are not available.

neuroscience↗

bioRxiv2024

Elastase mediated white matter damage in cerebral small vessel disease: Microglia - neutrophils pas de deux

Cerebral small vessel disease (CSVD) leads to an extensive white matter damage associated with cognitive decline, yet the underlying damaging mechanisms remain incompletely understood. Here we established a positive correlation between plasma levels of serine proteinase elastase ELANE and periventricular white matter hyperintensity (PV-WMH) in a cohort of CSVD patients. In a CSVD murine model induced by bilateral carotid artery stenosis (BCAS), upregulated ELANE was detected both in microglia and peripheral blood neutrophils. Genetic ELANE deficiency significantly alleviated oligodendrocyte loss, thereby reducing white matter lesions (WMLs) as well as ameliorating sensorimotor and cognitive impairments in BCAS mice. In vitro studies demonstrated that ELANE triggered time-dependent and dose-dependent oligodendrocyte lineage cell death. Bone marrow transplantation showed that ELANE from microglia and peripheral blood both contributed to WML development and BCAS-induced neurological deficits. Mechanistically, ELANE, accumulated by oligodendrocytes, cleaved the phosphodiesterase domain of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). Pharmacological inhibition of ELANE with Sivelestat reduced oligodendrocyte loss and WMLs leading to the restoration of white matter integrity and neurological improvements in BCAS mice. In post-mortem brain specimens of CSVD patients ELANE accumulated within WMLs being predominantly localized in microglia (and hence defined as microglial ELANE) rather than in the brain-infiltrating neutrophils. We therefore posit microglial ELANE as an instigator of whiter matter injury in CSVD and suggest its potential therapeutic relevance.

neuroscience↗

bioRxiv2024

Mechanical force regulates the inhibitory function of PD-1

The immune checkpoint molecule, programmed cell death 1 (PD-1), plays a pivotal role in regulating T-cell function. Upon binding to its ligands, PD-L1 or PD-L2, PD-1 suppresses T-cell receptor signaling, thereby preventing T-cell activation, making it a critical target in cancer immunotherapy. Although extensively studied, the molecular mechanism of PD-1s inhibitory function is still not fully understood, especially at the atomic level. Using the biomembrane force probe (BFP), we discovered that interactions between PD-1 and PD-L1/PD-L2 exhibit catch-slip bond behavior under force. At lower forces, catch bonds are observed, transitioning to slip bond as the force increases. Steered molecular dynamics (SMD) simulations revealed a force-induced bond state between PD-1 and its ligands, distinct from the force-free state observed in solved complex structures. Disrupting interactions that stabilize either state weakens the catch bond and diminishes PD-1s inhibitory function. Interestingly, soluble forms of PD-L1 and PD-L2 compete with their surface-bond counterparts, attenuating PD-1s suppression of T-cell activation. This suggests that soluble PD-1 ligands could potentially serve as anti-PD-1 drugs. Tumor growth studies in mice confirmed the anti-cancer activity of soluble PD-L1. Our findings highlight the critical role of mechanical force in PD-1s inhibitory function, suggesting that PD-1 may act as a mechanical sensor in suppressing T-cell activation. These insights indicate that mechanical regulation should be considered when designing PD-1 blocking inhibitors and other PD-1 related cancer immunotherapies. TeaserThis study shows that the interaction between PD-1 and its ligands is force-dependent, and soluble forms of PD-1 ligands can potentially serve as PD-1 blockers in cancer immunotherapy.

biophysics↗