Biology subjects

Wu, B.

Publications and source records attributed to Wu, B..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Zwitterionic polymer coating enabled chronic dopamine sensing and electrophysiology recording in free-moving mice

The brains complex network relies on both electrical and chemical signaling to support its physiological and cognitive functions. To fully understand neural circuit dynamics and their dysfunctions, it is crucial to simultaneously detect neurotransmitters and modulators alongside electrophysiological signals. The striatal dopamine circuits are integral to neurological processes such as movement, reward, learning, and circadian rhythm regulation, making it highly desirable to monitor both neural activity and dopamine (DA) levels in freely behaving animals. One promising approach involves the implantation of multimodal microelectrode arrays (MEAs). However, chronic electrochemical sensing of DA in freely moving animals faces significant challenges, including biofouling of sensing electrodes and the instability of Ag/AgCl reference electrodes. In this study, we developed two complementary strategies--surface grafting and photo crosslinking--to coat the MEA and implanted Ag/AgCl reference electrodes, respectively, with zwitterionic poly(sulfobetaine methacrylate) (PSB). The surface-grafted thin PSB coating effectively inhibits protein fouling and inflammatory responses to the MEA, while the PSB hydrogel protects the Ag/AgCl electrodes from delamination in vivo, ensuring a stable reference potential. By coating both the Ag/AgCl reference electrodes and flexible polyimide MEAs with PSB and PEDOT/CNT, we achieved stable DA detection and electrophysiological recordings in freely moving mice over a four-week period. Weekly electrochemical impedance spectroscopy confirmed the long-term stability of the implanted electrodes. Our method enables multidimensional analysis of behavioral patterns, electrophysiological activity, and DA dynamics, providing a comprehensive approach for neuroscience research. This work advances neurochemical and electrophysiological methodologies by offering reliable tools for longitudinal investigations of brain function in freely behaving animals.

bioengineering↗

bioRxiv2026

SPCoral: diagonal integration of spatial multi-omics across diverse modalities and technologies

Spatial multi-omics is indispensable for decoding the comprehensive molecular landscape of biological systems. However, the integration of multi-omics remains largely unresolved due to inherent disparities in molecular features, spatial morphology, and resolution. Here we developed SPCoral for diagonal integration of spatial multiomics across adjacent slices. SPCoral extracts spatial covariation patterns via graph attention networks, followed by the use of optimal transport to identify high-confidence anchors in an unsupervised, feature-independent manner. SPCoral utilizes a crossmodality attention network to enable seamless cross-resolution feature integration alongside robust cross-omics prediction. Comprehensive benchmarking demonstrates SPCorals superior performance across different technologies, modalities and varied resolutions. The integrated multi-omics representation further improves spatial domain identification, effectively augments experimental data, enables cross-modal association analysis, and facilitates cell-cell communication. SPCoral exhibits good scalability with data size, reveals biological insights that are not attainable using a single modality. In summary, SPCoral offers a powerful framework for spatial multi-omics integration across various technologies and biological scenarios.

bioinformatics↗

bioRxiv2026

Two orthogonal MAP3K-driven pathways of NLRP1 inflammasome activation revealed by poisonous beetles.

Environmental toxins that cause irritant dermatitis remain poorly understood as activators of innate immune pathways. Here, we identify rove beetle (Paederus) and blister beetle (Meloidae) toxins as previously unrecognized triggers of the human NLRP1 inflammasome in keratinocytes. Rove beetles, likely through the ribosome inhibitor pederin, activate NLRP1 via translational stalling and the ZAK-dependent ribotoxic stress response. In contrast, the phosphatase inhibitor cantharidin from blister beetles induces NLRP1 through TAK1-driven hyperphosphorylation of its linker region, independent of ZAK. In their hyperactivated states, ZAK and TAK1 share overlapping phosphosites on the NLRP1 disordered linker, including a common essential TZ motif. In addition, we show that TAK1 and ZAK are jointly responsible for NLRP1 linker phosphorylation and activation caused by dsRNA and CHIKV infection. These findings reveal medically relevant insect toxins as activators of NLRP1, and uncover parallel MAP3 kinase pathways as converging upstream activating signals for the human NLRP1 inflammasome. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=172 HEIGHT=200 SRC="FIGDIR/small/701189v1_ufig1.gif" ALT="Figure 1000"> View larger version (50K): org.highwire.dtl.DTLVardef@ee34b9org.highwire.dtl.DTLVardef@c79ec9org.highwire.dtl.DTLVardef@189c373org.highwire.dtl.DTLVardef@17ec853_HPS_FORMAT_FIGEXP M_FIG C_FIG KEY POINTSTwo dermatitis-causing beetle species induce NLRP1-driven pyroptosis of human keratinocytes Rove beetles, likely via pederin, activate NLRP1 via ribosome inhibition and ZAK[a]-driven RSR Cantharidin from blister beetles activates human via TAK1-, instead of ZAK[a]-driven hyperphosphorylation of the NLRP1 linker region Shared phosphosites by TAK1 and ZAK[a] on NLRP1 contribute to dsRNA-driven NLRP1 activation

immunology↗

bioRxiv2026

A Cell-Based Assay to Categorize Variants of Human Succinate Semialdehyde Dehydrogenase Associated with Autism Spectrum Disorder

Many genes are implicated in autism spectrum disorder (ASD) as a result of sequencing the genomes of individuals with ASD, however in most cases it remains unclear which genes are playing causative roles. ALDH5A1, which encodes the enzyme succinate semialdehyde dehydrogenase (SSADH), an important regulator of GABA metabolism, is causative in the syndrome SSADH deficiency and is also implicated in ASD. However, it is unknown how variants found in ASD affect SSADH function. We developed a yeast growth assay that models SSADH deficiency to quantify the functional impact of seven ALDH5A1 variants found in ASD. In this assay, expression of human ALDH5A1 partially complemented the growth defect caused by deletion of the ALDH5A1 ortholog UGA2. Using growth rate measurements, we calculated functional scores for 27 variants divided into calibration and ASD test variant groups. Functional scores for benign and pathogenic calibration variants segregated accordingly, validating the assay, while ASD variants displayed a range of activities from complete loss to normal function. Comparisons with published enzymatic assays and computational predictions showed broad agreement, while also identifying some limitations of these approaches. SUMMARY STATEMENTWe introduce a simple yeast assay to measure how autism-linked gene variants in ALDH5A1, which encodes the enzyme succinate semialdehyde dehydrogenase, affect its function, helping clarifying its role in autism.

neuroscience↗

bioRxiv2026

Distinct CA1 inputs support shifts in neural dimensionality and memory resolution

Event-based memories may be encoded with high (e.g., episodic) or low (e.g., gist) mnemonic resolution. While the CA1 region of the hippocampus encodes events at both scales, it is unclear how such dual coding emerges. Consistent with theoretical predictions1,2, here we show that trisynaptic (from CA3) and monosynaptic (from the medial entorhinal cortex) projections to CA1 encode high- and low-resolution event-based memories, respectively. Recruitment of the trisynaptic pathway during contextual fear conditioning promotes feedforward inhibition of CA1 via activation of parvalbumin-positive (PV+) interneurons. This allows sparse encoding of event-based memories in high-dimensional neural states that support high-resolution contextual fear memories, where mice exhibit conditioned fear only in the training context and not similar contexts. Inhibiting this input during training reduces activation of CA1 PV+ interneurons and feedforward inhibition, shifting neural dynamics to low-dimensional states that support low-resolution contextual fear memories where mice freeze in the training context and similar contexts. These experiments identify a circuit-based mechanism that causally links the dimensionality of CA1 neural dynamics to mnemonic resolution.

neuroscience↗

bioRxiv2025

Senescent host-derived extracellular vesicles potentiate antitumor immunity via bystander T cell activation

Extracellular vesicles (EVs) are key mediators of intercellular communication, and those from the plasma of aged individuals are typically viewed as drivers of aging or even cancer. Here, we uncover a latent, potent antitumor capacity inherent to EVs derived from aged hosts. Specifically, we demonstrate that extracellular vesicles from the plasma of aged mice (A-EVs) exhibit robust tumor-suppressive activity in young tumor-bearing recipients. Mechanistically, A-EVs engage a dual mode of action: they directly induce senescence in cancer cells, enhancing their immunogenicity. More importantly, they concurrently activate non-tumor-specific bystander CD8 T cells within the tumor microenvironment via cross-presentation of pathogen-derived antigens, thereby reshaping the immunosuppressive tumor microenvironment. This synergistic interplay potently reinvigorates antitumor immunity and sensitizes tumors to PD-L1 checkpoint blockade. Our findings establish A-EVs as a novel class of endogenous immunomodulators with broad therapeutic potential for cancer immunotherapy.

immunology↗

bioRxiv2025

Transcriptomic Signature and PROTAC Strategy Revealed Histone Lysine Demethylase as a Target of Anticancer Activity of Deferiprone.

Deferiprone (DFP) is an iron chelator approved for treating iron overload in thalassemia patients. Recent observations have suggested that DFP has promising anticancer activities ascribed to several mechanisms including reduction of the intracellular free labile iron and zinc ion pools and inhibition of the activities of other intracellular targets, including ribonucleotide reductase (RNR). We previously reported that DFP inhibits the demethylase activities of several Fe(II)/- ketoglutarate dependent histone lysine demethylases (KDMs) at much lower concentrations at which it inhibits RNR activities and/or reduces the labile intracellular iron and zinc ion pools. In this study, we used RNA sequencing (RNA seq) and PROTACs strategies to validate and quantify the contribution of intracellular KDM inhibition to the antiproliferative activities of DFP. We report herein that DFP elicited gene expression signature that is largely similar to that of JIB-04, an established KDM inhibitor (KDMi), in two breast cancer (BCa) cells (MCF-7 and MDA-MD-231). Importantly, RNA seq revealed that DFP and JIB-04 downregulated the expression of hypoxia-inducible factor 1 (HIF-1), an oncogene whose expression is commonly modulated through histone demethylation mediated by KDMs and degraded by several KDMi. Moreover, DFP-derived PROTACs elicited enhanced cancer cell selective antiproliferative activities and intracellular on-target effects, downregulating several KDMs implicated in the etiology of BCa cells, including a strong degradation of KDMs 2A, 3A and 5B, and a moderate degradation of KDMs 4A-C, 5C, 6B. Collectively, our data supports KDM inhibition as a key mechanism of anticancer activity of DFP and identifies PROTAC is a viable strategy to obtain novel DFP analogs with improved potency and therapeutic index.

cancer biology↗

bioRxiv2025

Reactivation-coupled brain stimulation enables complete learning generalization

Generalization of learned knowledge to new contexts is essential for adaptive behavior. Despite extensive research on the brain plasticity mechanisms underlying learning specificity, the mechanisms that facilitate generalization remain poorly understood. Here, we investigate whether using brain stimulation to disrupt offline consolidation in visual cortex promotes learning generalization. Separate groups of participants (N = 144) were trained on visual detection tasks using either a reactivation-based protocol or conventional full-practice, combined with anodal or sham transcranial direct current stimulation (tDCS) over the visual cortex. Strikingly, only combination of reactivation-based learning with anodal tDCS produced complete generalization from trained to untrained stimuli, an effect consistently replicated across features (orientation, motion direction). In contrast, reactivation-based learning alone and conventional full-practice - whether with or without brain stimulation - yielded stimulus-specific learning. Importantly, reactivation-coupled brain stimulation achieved generalization with an 80% reduction in training trials while maintaining learning gains comparable to full-practice. These findings demonstrate that reactivation and neuromodulation interact to unlock learning generalization, revealing a key brain plasticity mechanism and offering a rapid, translatable strategy for sensory rehabilitation.

neuroscience↗

bioRxiv2025

DNAH14 deficiency impairs sperm motility by reducing flagellar beat amplitude

Male infertility affects approximately 15-20% of couples worldwide, with asthenozoospermia accounting for 19% of cases. Nevertheless, the genetic basis of many asthenozoospermia cases remains poorly understood. In this study, we generated Dnah14 knockout mice, which displayed subfertility due to impaired sperm motility despite normal sperm morphology. Comprehensive kinematic analysis revealed that Dnah14-deficient spermatozoa exhibited reduced flagellar beat amplitude but increased beat frequency, while other dynein components remained unaffected. Notably, increasing sperm concentration during in vitro fertilization (IVF) experiments partially rescued the fertilization defects caused by Dnah14 deletion, suggesting a compensatory mechanism for this specific form of asthenozoospermia. Our results establish DNAH14 as a critical regulator of sperm motility and propose a potential therapeutic strategy for affected individuals.

developmental biology↗

bioRxiv2025

Characterization and Genome Insights of Two Novel Plastic-Degrading Acinetobacter Species

The ubiquitous presence of Acinetobacter species in the environment holds significant biotechnology potential, particularly in the degradation of various pollutants. In this study, we present two plastic-degrading bacteria, strains CAAS 2-6T and CAAS 2-13T, isolated from landfill leachate and a strawberry farmland, respectively. Strain CAAS 2-6T showed the highest 16S rRNA sequence similarity (97.7%) with Acinetobacter gerneri DSM 14967T, while strain CAAS 2-13T was most closely related (99.6%) to Acinetobacter gerneri PS-1T. Phylogenetic analysis of 16S rRNA and gyrB-rpoB genes placed both strains on distinct branches. Genomic comparisons revealed the highest digital DNA-DNA hybridization (dDDH) / average nucleotide identity (ANI) values for CAAS 2-6T with Acinetobacter indicus CIP 110367T (22.7%/77.0%) and for CAAS 2-13T with Acinetobacter gerneri PS-1T (66.5%/96.0%). Based on phenotypic and chemotaxonomic data, we propose strain CAAS 2-6T as the novel species Acinetobacter lentus sp. nov. (type strain CAAS 2-6T = GDMCC 1.3951T = JCM 36321T = KCTC 8156T), and strain CAAS 2-13T as the novel subspecies Acinetobacter kanungonis subsp. fragariae subsp. nov. (type strain CAAS 2-13T = GDMCC 1.3956T = JCM 36322T = KCTC 8157T). Both strains utilized PLA, PBSA, PBS, PBAT, and PBT as sole carbon sources, with CAAS 2-6T exhibiting superior growth on PBSA, PBS, and PBAT. Genomic annotation identified genes encoding plastic-degrading enzymes multicopper oxidase AbMCO and alkane hydroxylase AlkB. Enzymatic depolymerization assays confirmed in vitro production of plastic monomers. These findings expand the known metabolic capabilities of Acinetobacter and provide promising new candidates for plastic bioremediation. IMPORTANCEAcinetobacter spp. demonstrate significant potential for plastic bioremediation. We characterize two novel strains: CAAS 2-6T (A. lentus sp. nov.) and CAAS 2-13T (A. kanungonis subsp. fragariae subsp. nov.), capable of degrading five major polyesters (PLA, PBAT, PBT, PBS, PBSA) as sole carbon sources. Genomic and enzymatic analyses identified multicopper oxidase (AbMCO) and alkane hydroxylase (AlkB) as key depolymerase. This work: (i) Expands plastic-degrading Acinetobacter diversity; (ii) Provides novel biocatalysts and genomic resources; (iii) Delivers engineerable microbial chassis.

microbiology↗

bioRxiv2025

easyClock: A User-Friendly Desktop Application for Circadian Rhythm Analysis and Visualization

Circadian rhythms regulate a wide range of biological processes, and their precise characterization is essential for understanding behavioral and physiological fluctuations. However, existing tools to analyze circadian data often require coding expertise or rely on specific data acquisition software, limiting their general applicability. Here, we present easyClock, an intuitive and interactive application designed to streamline circadian rhythm analysis and visualization. The easyClock application enables simultaneous processing of multiple files, allowing users to preview, batch-analyze, and plot diverse sets of time series generated from high-throughput experiments. To enhance data analysis efficiency and provide comparable results, this application integrates four different analysis methods for handling data with various waveforms. Results are easily viewed and exported for any selected range of data. This free-to-use application is open-source and can be deployed on macOS computers by users without coding experience. AvailabilityThe source code for the latest version of easyClock is available at https://github.com/HungryFly/easyClock_for_CircadianRhythms. To download the installation package and access version updates, please refer to https://github.com/Dr-WUBINBIN/easyClock/releases.

bioinformatics↗

bioRxiv2025

Spectral theory of stochastic gene expression: a Hilbert space framework

A survey of the literature reveals notable discrepancies among the purported exact results for the spectra of stochastic gene expression models. For self-repressing gene circuits, previous studies ([Phys. Rev. Lett. 99, 108103 (2007)], [Phys. Rev. E 83,062902 (2011)], [J. Chem. Phys. 160, 074105 (2024)], and [bioRxiv 2025.02.05.635946 (2025)]) have provided different exact solutions for the eigenvalues of the generator matrix. In this work, we propose a unified Hilbert space framework for the spectral theory of stochastic gene expression. Based on this framework, we analytically derive the spectra for models of constitutive, bursty, and autoregulated gene expression. The eigenvalues and eigenvectors obtained are then used to construct an exact spectral representation of the time-dependent distribution of gene product numbers. The spectral gap between the zero eigenvalue and the first nonzero eigenvalue, which reflects the relaxation rate of the system towards its steady state, is then compared with the prediction of the deterministic model, and we find that deterministic modeling fails to capture the relaxation rate when autoregulation is strong. In particular, our results demonstrate that for infinite-dimensional operators such as in stochastic gene expression models, many conclusions in linear algebra do not apply, and one must rely on the modern theory of functional analysis.

molecular biology↗

bioRxiv2025

A Reductive Uric Acid Degradation Pathway in Anaerobic Bacteria

Uric acid is a key intermediate in purine degradation across diverse organisms, while its accumulation in humans leads to inflammation and gout disease. Aerobic organisms degrade uric acid via a well-known "oxidative pathway" involving dearomatization of the purine core catalyzed by uric acid oxidases or dehydrogenases. The ability to degrade uric acid is also widespread in anaerobic bacteria, including gut bacteria, although the mechanisms are incompletely understood. Here, we report the biochemical characterization of a recently identified uric acid degradation gene cluster from Escherichia coli, and show that it encodes a "reductive pathway" for uric acid degradation. In this pathway, uric acid is first reduced to isoxanthine (2,8-dioxopurine) by a xanthine dehydrogenase homolog (XdhD), followed by dearomatization of the purine core catalyzed by a flavin-dependent reductase (YgfK). Stepwise cleavage of the pyrimidine and imidazole rings forms 2,3-diureidopropionate, and stepwise cleavage of the 2- and 3-ureido groups then forms 2,3-diaminopropionate, which is cleaved by a pyridoxal 5-phosphate-dependent lyase (YgeX) to pyruvate and ammonia. Detection of isoxanthine in clinical serum samples suggests it is a physiologically relevant circulating metabolite. A probiotic E coli Nissle strain was engineered for constitutive overexpression of the gene cluster, and oral administration in a uricase-knockout hyperuricemic mouse model significantly reduced the serum uric acid level and alleviated associated kidney injury, suggesting a potential route towards uricolytic probiotics.

biochemistry↗

bioRxiv2025

Small Molecule Modulators of TOX protein to Re-invigorate T cell Activity

The TOX protein (thymocyte selection-associated high mobility group box) is a critical transcription factor implicated in both T acute lymphoblastic leukemia (T-ALL) and CD8+ T cell exhaustion. Gene perturbation studies suggest that inhibiting TOX may have therapeutic implications for both leukemia and T cell exhaustion. However, due to its complex molecular mechanisms and intrinsically disordered structure, TOX has not been effectively targeted by small molecules to date. In this study, we used small molecule microarray (SMM) screening and biochemical assays to identify a series of TOX protein-protein interaction (PPI) inhibitors. We identified KI-TOX-A3 as a TOX protein binder and potent TOX PPI inhibitor. In T-ALL, KI-TOX-A3 revealed selective cytotoxicity and proteosome-dependent TOX degradation. In CD8+ T cells, KI-TOX-A3 potently reversed T cell exhaustion by decreasing surface inhibitory receptors, increasing expression of effector cytokines, and enhancing cancer cell killing activity. We also demonstrate the utility of KI-TOX-A3 to probe potential epigenetic regulatory mechanisms of TOX via KAT7 acetylation in T cells.

biochemistry↗

bioRxiv2025

Unveiling Protein-DNA Interdependency: Harnessing Unified Multimodal Sequence Modeling, Understanding and Generation

The interdependent orchestration of proteins, coding DNA sequences (CDS), and adjacent regulatory DNA elements underpins biological functionality, where evolutionary constraints shape codon usage, transcriptional regulation, and structural stability. We present ProDMM, a multimodal framework that deciphers these systemic relationships through unified sequence modeling. Integrating a context-aware encoder with conditional generation, our architecture captures codependent patterns between protein motifs and cis-regulatory syntax. ProDMMs encoder demonstrates superior predictive capabilities in forecasting pathway-level phenotypes and protein expression profiles, outperforming conventional single-modality approaches. Its decoder generates synthetically optimized regulatory elements by resolving spatial dependencies between coding sequences and adjacent non-coding regions, enabling transcriptional fine-tuning unavailable to sequence-agnostic methods. By resolving how localized CDS-NCDS-protein interdependencies propagate to system-level phenotypes, ProDMM establishes a paradigm for holistic biological sequence engineering. This approach enables coordinated optimization of translation efficiency, enzymatic activity, and pathway flux, offering transformative potential for designing tailored biosynthesis systems and advancing sustainable bioproduction strategies.

bioinformatics↗

bioRxiv2025

Discovery of Expression-Governing Residues in Proteins

Understanding how amino acids influence protein expression is crucial for advancements in biotechnology and synthetic biology. In this study, we introduce Venus-TIGER, a deep learning model designed to accurately identify amino acids critical for expression. By constructing a two-dimensional matrix that links model representations to experimental fitness, Venus-TIGER achieves improved predictive accuracy and enhanced extrapolation capability. We validated our approach on both public deep mutational scanning datasets and low-throughput experimental datasets, demonstrating notable performance compared to traditional methods. Venus-TIGER exhibits robust trans-ferability in zero-shot predicting scenarios and enhanced predictive performance in few-shot learning, even with limited experimental data. This capability is particularly valuable for protein design aimed at enhancing expression, where generating large datasets can be costly and time-consuming. Additionally, we conducted a statistical analysis to identify expression-associated features, such as sequence and structural preferences, distinguishing between those linked to high and low expression. Our investigation also revealed a correlation among stability, activity and expression, providing insight into their interconnected roles and underlying mechanisms.

bioengineering↗

bioRxiv2024

A TROP2/Claudin Program Mediates Immune Exclusion to Impede Checkpoint Blockade in Breast Cancer

BackgroundImmune exclusion inhibits anti-tumor immunity and response to immunotherapy, but its mechanisms remain poorly defined. In triple-negative breast cancer (TNBC), an aggressive and generally immune-rich subtype, an immune-cold microenvironment predicts poor prognosis due to a limited response to chemotherapy and immune checkpoint inhibitors. This study aimed to identify mechanisms regulating immune infiltration in TNBC. MethodsWe performed spatial transcriptomic analysis comparing immune-enriched versus immune-cold treatment-naive TNBCs. Functional analyses, including loss-of-function and reconstitution experiments, were conducted to investigate the role of Trophoblast Cell-Surface Antigen 2 (TROP2), a key target of anti-cancer Antibody Drug Conjugates (ADCs), in promoting TNBC progression. A humanized TROP2 syngeneic TNBC model was used to assess the effects of TROP2-targeting in combination with anti-PD1 therapy. Additionally, data from patients treated with immune checkpoint blockade were used to test hypotheses from the preclinical findings. ResultsWe reveal that TROP2 controls barrier-mediated immune exclusion in TNBC through Claudin 7 association and tight junction regulation. TROP2 expression is inversely correlated with T cell infiltration and predicts poor outcomes in TNBC. We demonstrate that TROP2 is sufficient to drive tumor progression in vivo in a CD8 T cell-dependent manner, while its loss deregulates expression and localization of multiple tight junction proteins, enabling T cell infiltration. We show that TROP2 targeting via hRS7, the antibody component of the ADC Sacituzumab govitecan (SG), enhances the anti-PD1 response and improves T cell accessibility and effector function. Correspondingly, TROP2 expression is highly associated with lack of response to anti-PD1 therapy in human breast cancer. ConclusionsThis study defines a new mechanism of barrier-mediated immune exclusion in cancer controlled by TROP2-dependent tight junctions. This mechanism drives tumor progression but can be targeted via TROP2-directed therapy to activate anti-tumor immunity and enhance immunotherapy response. What is already known on this topicBarrier-mediated immune exclusion is emerging as a mechanism of immune evasion in cancer such as triple-negative breast cancer (TNBC), but its molecular underpinnings remain poorly understood. TROP2 is a surface glycoprotein targeted by antibody-drug conjugates such as Sacituzumab govitecan, yet its functional role beyond drug delivery has been unclear. What this study addsThis study identifies TROP2 as a key regulator of tight junction-mediated immune exclusion in TNBC, independent of its intracellular signaling function. TROP2 promotes an immune-cold tumor microenvironment by enforcing mechanical barriers that limit T cell infiltration. How this study might affect research, practice or policyThese findings establish TROP2 as a functional driver of immune evasion and provide a mechanistic rationale for combining TROP2-targeting therapies with immune checkpoint inhibitors to overcome resistance in immune-excluded tumors.

cancer biology↗

bioRxiv2024

TurboID-based proximity labeling discovers ABCF2 as an adhesion receptor for the zoonotic pathogen Pasteurella multocida

Pasteurella multocida is a zoonotic pathogen that can cause fatal infections in both animals and humans. A significant number of putative adhesive factors have been predicted to contribute to the pathogenesis of P. multocida, but their interactive proteins on host cells remain unclear. In this study, we experimentally verified the roles of three previously proposed proteins (PlpE, PtfA, Hsf-2) in the adherence of P. multocida. Through turboID-based proximity labeling screening, we identified ATP-binding cassette sub-family F member 2 (ABCF2) as a host interactive protein for PlpE/PtfA/Hsf-2. Crucial amino acid residues in PlpE, PtfA, and/or Hsf-2 that are essential for interacting with ABCF2 included Asp-123 (PlpE), Lys-88 (PtfA), Asp-136 (PtfA), Ala-464 (Hsf-2), Glu-473 (Hsf-2), and Arg-489 (Hsf-2). Knocking down or knocking out ABCF2 significantly reduced the adherence and invasion of P. multocida to host cells, while overexpression of ABCF2 markedly increased these effects. However, ABCF2 did not contribute to the adherence of other bacterial species such as Klebsiella pneumoniae and Bordetella bronchiseptica. Additionally, we demonstrated that P. multocida infection upregulated the expression of host ABCF2 by activating the p38 MAPK and NF-{kappa}B signaling pathways. Furthermore, we showed that ABCF2 was involved in the P. multocida-induced p53-dependent apoptotic signaling pathway. To the best of our knowledge, this is the first identification of ABCF2 as a host factor contributing to the adherence of P. multocida and only the second report of ABCF2s involvement in bacterial pathogenesis. ImportanceP. multocida can cause fatal infections in both animals and humans, yet the mechanisms related to its pathogenesis remain to be fully explored. In this study, we identified ABCF2 as a crucial host interactive protein for three adhesive proteins encoded by P. multocida and experimentally verified its role in the adherence and invasion of P. multocida. Furthermore, we elucidated how P. multocida modulates ABCF2 during its infection and revealed p53-dependent apoptosis as a downstream effect of ABCF2 during P. multocida infection. Given the absence of reports on ABCF2 contributing to the pathogenesis of P. multocida and only one previous report on the involvement of ABCF2 in bacterial pathogenesis prior to this study, this research could be valuable for comprehending the interactions between bacteria and hosts during bacterial infections.

microbiology↗