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Borrelia (or Borreliella ) burgdorferi,the causative agent of Lyme disease,is a motile and invasive zoonotic pathogen adept at navigating between its arthropod vector and mammalian host. While motility and chemotaxis are well known to be essential for its enzootic cycle,the role of each methyl-accepting chemotaxis proteins (MCPs) in the infectious cycle of B . burgdorferi remains unclear. In this study,we show that mcp5,a gene encoding one of the most abundant MCPs in B . burgdorferi,is differentially expressed in response to environmental signals and at distinct stages of the pathogen’s enzootic cycle. Notably,mcp5 expression is regulated by the Hk1-Rrp1 and Rrp2-RpoN-RpoS pathways,two key regulatory pathways that are critical for the spirochete’s colonization of the tick vector and mammalian host,respectively. Infection experiments with an mcp5 mutant revealed that spirochetes lacking MCP5 were unable to establish infections in either C3H/HeN mice or Severe Combined Immunodeficiency (SCID) mice,which are deficient in adaptive immunity,underscoring MCP5’s critical role in mammalian infection. However,the mcp5 mutant was able to establish infection and disseminate in NOD SCID Gamma (NSG) mice,which are deficient in both adaptive and most innate immune responses,suggesting that MCP5 plays an important role in evading host innate immunity. Moreover,NK cell depletion in C3H and SCID mice restored the infectivity of the mcp5 mutant,further highlighting MCP5’s role in evading NK cell-associated immunity. Co-culture assays with NK cells and macrophages revealed that the mcp5 mutant enhanced interferon-gamma production by NK cells. In the tick vector,the mcp5 mutants survived feeding but failed to transmit to mice. These findings reveal that MCP5,regulated by both the Rrp1 and Rrp2 pathways,is critical for establishing infection in mammalian hosts by evading NK cell-mediated host innate immunity and is important for the transmission of spirochetes from ticks to mammalian hosts. This work provides a foundation for further elucidation of chemotactic signals sensed by MCP5 that facilitate B . burgdorferi in evading host defenses. View Publication

LRRK2 is a kinase whose activity is linked to Parkinson’s disease. This study identifies a pathway that links LRRK2 activation to lysosome perturbations. This pathway involves the process known as CASM and culminates in an interaction between LRRK2 and GABARAP at the surface of lysosomes. View Publication

Many respiratory viruses attack the airway epithelium and cause a wide spectrum of diseases for which we have limited therapies. To date,a few primary human stem cell-based models of the proximal airway have been reported for drug discovery but scaling them up to a higher throughput platform remains a significant challenge. As a result,most of the drug screening assays for respiratory viruses are performed on commercial cell line-based 2D cultures that provide limited translational ability. We optimized a primary human stem cell-based mucociliary airway epithelium model of SARS-CoV-2 infection,in 96-well air–liquid-interface (ALI) format,which is amenable to moderate throughput drug screening. We tested the model against SARS-CoV-2 parental strain (Wuhan) and variants Beta,Delta,and Omicron. We applied this model to screen 2100 compounds from targeted drug libraries using a high throughput-high content image-based quantification method. The model recapitulated the heterogeneity of infection among patients with SARS-CoV-2 parental strain and variants. While there were heterogeneous responses across variants for host factor targeting compounds,the two direct-acting antivirals we tested,Remdesivir and Paxlovid,showed consistent efficacy in reducing infection across all variants and donors. Using the model,we characterized a new antiviral drug effective against both the parental strain and the Omicron variant. This study demonstrates that the 96-well ALI model of primary human mucociliary epithelium can recapitulate the heterogeneity of infection among different donors and SARS-CoV-2 variants and can be used for moderate throughput screening. Compounds that target host factors showed variability among patients in response to SARS-CoV-2,while direct-acting antivirals were effective against SARS-CoV-2 despite the heterogeneity of patients tested. View Publication

Pseudomonas aeruginosa is a Gram-negative bacterium that is notorious for airway infections in cystic fibrosis (CF) subjects. Bacterial quorum sensing (QS) coordinates virulence factor expression and biofilm formation at population level. Better understanding of QS in the bacterium-host interaction is required. Here,we set up a new P. aeruginosa infection model,using 2D upper airway nasal organoids that were derived from 3D organoids. Using dual RNA-sequencing,we dissected the interaction between organoid epithelial cells and WT or QS-mutant P. aeruginosa strains. Since only a single healthy individual and a single CF subject were used as donors for the organoids,conclusions about CF-specific effects could not be deduced. However,P. aeruginosa induced epithelial inflammation,whereas QS signaling did not affect the epithelial airway cells. Conversely,the epithelium influenced infection-related processes of P. aeruginosa,including QS-mediated regulation. Comparison of our model with samples from the airways of CF subjects indicated that our model recapitulates important aspects of infection in vivo. Hence,the 2D airway organoid infection model is relevant and may help to reduce the future burden of P. aeruginosa infections in CF. The online version contains supplementary material available at 10.1038/s41598-024-82500-w. View Publication

PRDX2 is significantly expressed in various cancers and is associated with the proliferation of tumor cells. Nonetheless,the precise mechanism of PRDX2 in tumor immunity remains incompletely understood. This study aims to investigate the impact of PRDX2,which is highly expressed in lung adenocarcinoma,on T cells in the tumor immune microenvironment,and its immune action target to promote the immune escape of lung cancer cells,to provide a theoretical basis for lung adenocarcinoma treatment with PRDX2 as the target. Mouse animal models to verify the effect of Conoidin A treatment on tumor growth and T cell infiltration. Flow cytometry and Western blot verified tumor cell apoptosis in the in vitro co-culture system as well as granzyme B and perforin expression in T cells. RNA-Seq was used to obtain the downstream immune molecule. si-RNA knockdown of Galectin-9 was co-cultured with T cells in vitro. Immunofluorescence and Western blot verified that PRDX2 regulates Galectin-9 expression through HDAC3. PRDX2 expression was negatively correlated with CD8 + T cell expression in LUAD patients. Inhibition of PRDX2 significantly enhanced T-cell killing of LUAD cells and reduced tumor load in both in vitro and in vivo models. Mechanistically,Conoidin A or shRNA_PRDX2 decreased Galectin-9 expression by down-regulating the phosphorylation of HDAC3,consequently enhancing the infiltration and function of CD8 + T cells. This study reveals the role of the PRDX2/HDAC3/Galectin-9 axis in LUAD immune escape and indicates Galectin-9 as a promising target for immunotherapy. The online version contains supplementary material available at 10.1186/s12967-024-05888-z. View Publication

Melanoma brain metastasis is linked to dismal prognosis and low overall survival and is detected in up to 80% of patients at autopsy. Circulating tumor cells (CTC) are the smallest functional units of cancer and precursors of fatal metastasis. We previously used an unbiased multilevel approach to discover a unique ribosomal protein large/small subunit (RPL/RPS) CTC gene signature associated with melanoma brain metastasis. In this study,we hypothesized that CTC-driven melanoma brain metastasis secondary metastasis (“metastasis of metastasis” per clinical scenarios) has targeted organ specificity for the liver. We injected parallel cohorts of immunodeficient and newly developed humanized NBSGW (huNBSGW) mice with cells from CTC-derived melanoma brain metastasis to identify secondary metastatic patterns. We found the presence of a melanoma brain–liver metastasis axis in huNBSGW mice. Furthermore,RNA sequencing analysis of tissues showed a significant upregulation of the RPL/RPS CTC gene signature linked to metastatic spread to the liver. Additional RNA sequencing of CTCs from huNBSGW blood revealed extensive CTC clustering with human B cells in these mice. CTC:B-cell clusters were also upregulated in the blood of patients with primary melanoma and maintained either in CTC-driven melanoma brain metastasis or melanoma brain metastasis CTC–derived cells promoting liver metastasis. CTC-generated tumor tissues were interrogated at single-cell gene and protein expression levels (10x Genomics Xenium and HALO spatial biology platforms,respectively). Collectively,our findings suggest that heterotypic CTC:B-cell interactions can be critical at multiple stages of metastasis. This study provides important insights into the relevance of prometastatic CTC:B-cell clusters in melanoma progression,extends the importance of the CTC RPL/RPS gene signature beyond primary metastasis/melanoma brain metastasis driving targeted organ specificity for liver metastasis (“metastasis of metastasis”),and identifies new targets for clinical melanoma metastasis therapies. View Publication

Growing evidence shows that the reprogramming of fatty acid (FA) metabolism plays a key role in HER2-positive (HER2 +) breast cancer (BC) aggressiveness,therapy resistance and cancer stemness. In particular,HER2 + BC has been defined as a "lipogenic disease" due to the functional and bi-directional crosstalk occurring between HER2-mediated oncogenic signaling and FA biosynthesis via FA synthase activity. In this context,the functional role exerted by the reprogramming of CD36-mediated FA uptake in HER2 + BC poor prognosis and therapy resistance remains unclear. In this study,we aimed to elucidate whether enhanced CD36 in mesenchymal HER2 + cancer stem cells (CSCs) is directly involved in anti-HER2 treatment refractoriness in HER2 + BC and to design future metabolism-based approaches targeting both FA reprogramming and the “root” of cancer. Molecular,biological and functional characterization of CD36-mediated FA uptake was investigated in HER2 + BC patients,cell lines,epithelial and mesenchymal CSCs. Cell proliferation was analyzed by SRB assay upon treatment with lapatinib,CD36 inhibitor,or Wnt antagonist/agonist. Engineered cell models were generated via lentivirus infection and transient silencing. CSC-like properties and tumorigenesis of HER2 + BC cells with or without CD36 depletion were examined by mammosphere forming efficiency assay,flow cytometry,cell sorting,ALDH activity assay and xenograft mouse model. FA uptake was examined by flow cytometry with FA BODIPY FL C16. Intratumor expression of CSC subsets was evaluated via multiplex immunostaining and immunolocalization analysis. Molecular data demonstrated that CD36 is significantly upmodulated on treatment in therapy resistant HER2 + BC patients and its expression levels in BC cells is correlated with FA uptake. We provided evidence of a consistent enrichment of CD36 in HER2 + epithelial-mesenchymal transition (EMT)-like CSCs from all tested resistant cell models that mechanistically occurs via Wnt signaling pathway activation. Consistently,both in vitro and in vivo dual blockade of CD36 and HER2 increased the anti-CSC efficacy of anti-HER2 drugs favoring the transition of the therapy resistant mesenchymal CSCs into therapy-sensitive mesenchymal-epithelial transition (MET)-like epithelial state. In addition,expression of CD36 in intratumor HER2 + mesenchymal CSCs is significantly associated with resistance to trastuzumab in HER2 + BC patients. These results support the metabolo-oncogenic nature of CD36-mediated FA uptake in HER2 + therapy-refractory BC. Our study provides evidence that targeting CD36 might be an effective metabolic therapeutic strategy in the treatment of this malignancy. The online version contains supplementary material available at 10.1186/s13046-025-03276-z. View Publication

Neurons derived from induced pluripotent stem cells (h-iPSC-Ns) provide an invaluable model for studying the physiological aspects of human neuronal development under healthy and pathological conditions. However,multiple studies have demonstrated that h-iPSC-Ns exhibit a high degree of functional and epigenetic diversity. Due to the imprecise characterization and significant variation among the currently available maturation protocols,it is essential to establish a set of criteria to standardize models and accurately characterize and define the developmental properties of human neurons derived from iPSCs. In this study,we conducted comprehensive cellular and network level analysis of the functional development of human neurons,generated from iPSCs obtained from healthy young female peripheral blood mononuclear cells by BDNF and GDNF treatment. We provide a thorough description of the maturation process of h-iPSC-Ns over a 10-week in vitro period using conventional whole-cell patch clamp and dynamic clamp techniques,alongside with morphometry and immunocytochemistry. Additionally,we utilized calcium imaging to monitor the progression of synaptic activity and network communication. At the single cell level,human neurons exhibited gradually decreasing membrane resistance in parallel with improved excitability. By the fifth week of maturation,firing profiles were consistent with those of mature regular firing type of neurons. At the network level,fast glutamatergic and depolarizing GABAergic synaptic connections were abundant together with synchronized network activity from the sixth week of maturation. Alterations in the expression of GABA A receptor subunits were also observed during the process of maturation. The sequence of differentiation events was consistent,providing a robust temporal framework to execute experiments at defined stages of neuronal maturation as well as to use a specific set of experiments to assess a culture’s maturation. The uncovered progression of differentiation events provides a powerful tool to aid the planning and designing of targeted experiments during defined stages of neuronal maturation. View Publication

Chordoma is a slow-growing,primary malignant bone tumor that arises from notochordal tissue in the midline of the axial skeleton. Surgical excision with negative margins is the mainstay of treatment,but high local recurrence rates are reported even with negative margins. High-dose radiation therapy (RT),such as with proton or carbon ions,has been used as an alternative to surgery,but late local failure remains a problem. B7-H3 is an immune checkpoint,transmembrane protein that is dysregulated in many cancers,including chordoma. This study explores the efficacy of B7-H3 chimeric antigen receptor T (CAR-T) therapy in vitro and in vivo. Chordoma cancer stem cells (CCSCs) were identified using flow cytometry,sphere formation,and western blot analysis. The expression of B7-H3 in paraffin-embedded chordoma tissue was determined by immunohistochemical staining,and the expression of B7-H3 in chordoma cells was measured by flow cytometry. Retroviral particles containing either B7-H3 or CD19 CAR-expressing virus were transduced into T cells derived from peripheral blood mononuclear cells isolated from healthy human donor blood to prepare CAR-T cells. Animal bioluminescent imaging was used to evaluate the killing effect of CAR-T cells on chordoma cells in vivo. An irradiator was used for all irradiation (IR) experiments. The combination of B7-H3 CAR-T cell therapy and IR has a greater killing effect on killing radiation-resistant CCSCs and bulk chordoma cells compared with CAR-T cell or IR monotherapy. Additionally,increased expression of B7-H3 antigens on CCSCs and bulk tumor cells is associated with enhanced CAR-T cell killing in vitro and in vivo xenograft mouse models. Upregulation of B7-H3 expression by IR increases CCSCs sensitivity to B7-H3 CAR-T cell-mediated killing. Our preliminary data show that IR and B7-H3 CAR-T cell therapy is synergistically more effective than either IR or CAR-T cell monotherapy in killing chordoma cells in vitro and in a xenograft mouse model. These results provide preclinical evidence for further developing this combinatorial RT and B7-H3 CAR-T cell therapy model in chordoma View Publication

GABA B receptor (GABA B R) activation is known to alleviate pain by reducing neuronal excitability,primarily through inhibition of high voltage‐activated (HVA) calcium (Ca V 2.2) channels and potentiating G protein–coupled inwardly rectifying potassium (GIRK) channels. Although the analgesic properties of small molecules and peptides have been primarily tested on isolated murine dorsal root ganglion (DRG) neurons,emerging strategies to develop,study,and characterise human pluripotent stem cell (hPSC)‐derived sensory neurons present a promising alternative. In this study,hPSCs were efficiently differentiated into peripheral DRG‐induced sensory neurons (iSNs) using a combined chemical and transcription factor‐driven approach via a neural crest cell intermediate. Molecular characterisation and transcriptomic analysis confirmed the expression of key DRG markers such as BRN3A,ISLET1,and PRPH,in addition to GABA B R and ion channels including Ca V 2.2 and GIRK1 in iSNs. Functional characterisation of GABA B R was conducted using whole‐cell patch clamp electrophysiology,assessing neuronal excitability under current‐clamp conditions in the absence and presence of GABA B R agonists baclofen and α‐conotoxin Vc1.1. Both baclofen (100 μM) and Vc1.1 (1 μM) significantly reduced membrane excitability by hyperpolarising the resting membrane potential and increasing the rheobase for action potential firing. In voltage‐clamp mode,baclofen and Vc1.1 inhibited HVA Ca 2+ channel currents,which were attenuated by the selective GABA B R antagonist CGP 55845. However,modulation of GIRK channels by GABA B Rs was not observed in the presence of baclofen or Vc1.1,suggesting that functional GIRK1/2 channels were not coupled to GABA B Rs in hPSC‐derived iSNs. This study is the first to report GABA B R modulation of membrane excitability in iSNs by baclofen and Vc1.1,highlighting their potential as a future model for studying analgesic compounds. View Publication

Hematopoietic stem and progenitor cells (HSPCs) are critical for the treatment of blood diseases in clinic. However,the limited source of HSPCs severely hinders their clinical application. In the embryo,hematopoietic stem cells (HSCs) arise from hemogenic endothelial (HE) cells lining the major arteries in vivo. In this work,by engineering vascular niche endothelial cells (VN-ECs),we generated functional HSPCs in vitro from ECs at various sites,including the aorta-gonad-mesonephros (AGM) region and the placenta. Firstly,we converted mouse embryonic HE cells from the AGM region (aHE) into induced HSPCs (iHSPCs),which have the abilities for multilineage differentiation and self-renewal. Mechanistically,we found that VN-ECs can promote the generation of iHSPCs via secretion of CX3CL1 and IL1A. Next,through VN-EC co-culture,we showed that placental HE (pHE) cells,a type of extra-embryonic HE cells,were successfully converted into iHSPCs (pHE-iHSPCs),which have multilineage differentiation capacity,but exhibit limited self-renewal ability. Furthermore,comparative transcriptome analysis of aHE-iHSPCs and pHE-iHSPCs showed that aHE-iHSPCs highly expressed HSC-specific and self-renewal-related genes. Moreover,experimental validation showed that retinoic acid (RA) treatment promoted the transformation of pHE cells into iHSPCs that have self-renewal ability. Collectively,our results suggested that pHE cells possess the potential to transform into self-renewing iHSPCs through RA treatment,which will facilitate the clinical application of placental endothelial cells in hematopoietic cell generation. Subject terms: Haematopoietic stem cells,Haematopoietic stem cells View Publication

CDK4/6 inhibitors have significantly improved the survival of patients with HR-positive/HER2-negative breast cancer,becoming a first-line treatment option. However,the development of resistance to these inhibitors is inevitable. To address this challenge,novel strategies are required to overcome resistance,necessitating a deeper understanding of its mechanisms. Recent research has identified several dysregulated genes in CDK4/6 inhibitors-resistant breast cancer,but the underlying mechanism is complex due to tumor heterogeneity and warrants further investigation. RNA sequencing and KEGG pathway analysis was carried out to identify the mainly dysregulated genes in CDK4/6 inhibitors-resistant breast cancer cells. The effects of CXCR4 knockdown and overexpression via siRNAs and plasmids transfection were examined by mammosphere formation,RT-qPCR,flow cytometry,MTT and colony formation assays. The regulation mechanisms were analyzed by RT-qPCR,western blotting and immunofluorescence experiments. Mouse xenografts were used to analyze the role of CXCR4 in regulation palbociclib sensitivity in vivo. Additionally,we collected the clinical samples and performed immunohistochemistry to analyze the clinical significance of CXCR4. In our study,we focused on cancer stem cells,a critical contributor to cancer metastasis and therapy resistance,and detected an upregulation of stemness in our established palbociclib-resistant ER-positive breast cancer cells. Additionally,our research pinpointed CXCR4 as a pivotal gene responsible for maintaining cancer stemness and promoting palbociclib resistance. Mechanistically,CXCR4 activates the WNT5A/β-catenin signaling pathway by enhancing the expression of WNT5A and β-catenin,facilitating the nuclear translocation of β-catenin protein. Targeting CXCR4 using siRNAs or small molecular inhibitors effectively reduces cancer stemness and reverses palbociclib resistance both in vitro and in vivo. Clinical sample analysis further underscores the overactivation of the CXCR4/WNT5A/β-catenin axis in palbociclib-resistant breast cancer,suggesting CXCR4 as a potential biomarker for predicting resistance to CDK4/6 inhibitors. Collectively,our study demonstrates that CXCR4 overexpression plays a vital role in maintaining breast cancer stemness and promoting resistance to CDK4/6 inhibitors through the activation of the WNT5A/β-catenin pathway. Targeting CXCR4 may offer a promising therapeutic approach for advanced CDK4/6 inhibitor-resistant ER-positive breast cancer. The online version contains supplementary material available at 10.1186/s13058-025-01965-3. View Publication