Biology subjects

Song, W.

Publications and source records attributed to Song, W..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Enhanced liver regeneration via targeted mRNA delivery for partial in vivo reprogramming

Recent studies suggest that injury-induced dedifferentiation, which leads to the formation of injury-responsive cells, contributes significantly to tissue repair across various organs, including the liver. Utilizing Yamanaka factors (Oct4, Sox2, Klf4, and c-Myc: OSKM) for in vivo partial reprogramming generates injury-responsive cells in the intestine, mirroring those derived from injury-induced dedifferentiation. Thus, the transgene induction of OSKM or viral delivery of Oct4, Sox2, and Klf4 shows promise in facilitating tissue regeneration in the intestine, liver, skeletal muscle, and retina. Herein, we demonstrated that transient OSKM induction produces two distinct liver progenitor-like cell populations. One of these populations resembles liver progenitor-like cells (LPLCs) generated by acute acetaminophen (APAP) injury without triggering immune responses. To explore in vivo reprogramming as a viable strategy for tissue regeneration, we employed lipid nanoparticles (LNP) carrying OSKM mRNA (OSKM mRNA-LNP) to stimulate LPLCs formation. Notably, the production of Sox9+ LPLCs, and OSKM-induced dedifferentiation, was closely correlated with successful tissue regeneration in the liver post APAP injury. Thus, the OSKM mRNA-LNP approach represents a promising therapeutic intervention for the repair of acute liver injuries.

physiology↗

bioRxiv2025

Female sex hormones enhance gonococcal colonization at the endocervix by modifying cervical mucus

Neisseria gonorrhoeae is a human-exclusive pathogen that causes gonorrhea. Gonococci (GC) initiate female infections by colonizing the cervix, which can remain asymptomatic, cause cervicitis, or ascend to the upper female reproductive tract (FRT), leading to severe tissue damage. The FRT undergoes sex hormone-mediated changes during the menstrual cycle, which have long been implicated in the vulnerability to GC infection. One of the major changes is the increase and decrease in the production of the gel-forming mucin MUC5B by the endocervix in response to the level of estradiol (E2). This study examined the impact of sex hormones on GC infection of the human cervix, utilizing a human cervical tissue explant model. Tissue explants were treated without and with E2 alone or in combination with progesterone (E2+P4) to mimic various menstrual cycle phases. Treatment of E2 or E2+P4 enhanced GC colonization at the endocervix exclusively, but did not affect epithelial transmigration. While both treatments increased the number of GC microcolonies, E2+P4 increased GC colony size on the endocervical epithelium. These increases were independent of GC host receptors, carcinoembryonic antigen-related cell adhesion molecules. GC effectively diffused through cervical mucus to interact with the cervical epithelium under all hormone conditions and through mucin hydrogels with different MUC5B and MUC5AC compositions. Mucus gels collected from cervical explants and animal mucin mixtures enhanced GC aggregation in vitro. GC diffusion through mucin-hydrogels and aggregation in the presence of cervical mucus or animal mucins decreased as the MUC5B concentration increased. Our results suggest that female sex hormones promote GC colonization at the human endocervix by modulating the cervical mucus production, regulating womens susceptibility to GC infection, and further reveal the ability of GC to evade the mucus defense barrier for infection. Author SummaryNeisseria gonorrhoeae is a bacterial pathogen that primarily infects the human genital and female reproductive tracts, causing gonorrhea. While this bacterium can infect both men and women, the infection can lead to severe and permanent damage to womens reproductive systems. Currently, the relationship of gonococcal infection with the menstrual cycle is unknown. Here, we utilize a human cervical tissue explant model that mimics gonococcal infection in women to examine the impact of female sex hormones that drive the menstrual cycle on gonococcal infection. We found that estrogen alone or in combination with progesterone enhanced gonococcal colonization, increasing both the number and size of bacterial microcolonies on the cervical luminal surface, through regulating mucus production. Gonococci effectively penetrate through mucus layers to reach cervical epithelial cells and also prefer to aggregate with each other in the presence of mucus. Our results reveal that hormone-regulated mucus production changes the vulnerability of women to gonococcal infection, and that gonococci convert the mucus defense barrier into a colonization facilitator.

microbiology↗

bioRxiv2025

A T-cell Intrinsic Role for APOL1 Risk Alleles in Allograft Rejection

African Americans have an increased risk of kidney disease due to exonic variants in Apolipoprotein-L1 (G1 and G2). These prevalent variants have also been linked with kidney rejection, but outside of association with African ancestry, underpinning causal mechanisms are unknown. We investigated T-cell function using transgenic mice with physiologic expression of wild type (G0-), G1-, or G2-APOL1. Mice with variant APOL1 showed greater CD8+T-cell activation with expansion of a central memory (TCM) subset. Stimulated G1-CD8+T-cells showed enhanced proliferation and cytokine production, which reversed with APOL1 inhibition. In MHC-mismatched cardiac transplants, G1-mice demonstrated greater CD8+T-cell infiltration and reduced survival. Bulk transcriptome of G1-CD8+T-cells, and single-cell transcriptome of graft infiltrating TCMs, showed enrichment of canonical T-cell receptor (TCR) pathways including Ca2+-signaling. G1-CD8+T-cells demonstrated baseline ER-Ca2+ depletion followed by sustained increases in cytosolic-Ca2+ upon TCR stimulation. G1-CD8+T-cells were more sensitive to Ca2+ chelation, or store-operated Ca2+ entry inhibition, and relatively resistant to calcineurin antagonism vs. G0-CD8+T-cells. Analogously, in a kidney transplant cohort, APOL1-variant recipients developed rejection when they had elevated peripheral TCMs before transplantation and despite significantly higher tacrolimus levels vs G0/G0-AAs with rejection. In summary, we unravel an excitatory T-cell intrinsic mechanism for APOL1 exonic variants, causally linking them with kidney rejection.

immunology↗

bioRxiv2025

Vascularized Bioengineered Kidney Using Decellularized Scaffold Recellularized with human Placenta-Derived Angiogenic stem Cells and Kidney Organoids

A bioengineered kidney using a decellularized kidney scaffold (DKS) offers a promising solution to the kidney shortage. However, the transplantation of bioengineered kidneys using DKS recellularized with human endothelial, renal cells or others has not yet successfully achieved the vascular and renal reconstruction in vivo. In this study, we identified another type of stem cells, designated as human placenta-derived angiogenic stem cells (hPASCs), which serve as seeding cells for the vascularization of DKS. These hPASCs encompass angiogenic subpopulations, exhibit both stem cell properties and the capacity for vascular differentiation. Human fetal kidney organoids (KIO) were established as a source of renal parenchymal cells, comprising renal, immune, and vascular cell populations. We developed a vascularized bioengineered kidney by recellularizing DKS with hPASCs and KIO using a circulation perfusion culture system. The hPASCs bioengineered kidney demonstrated enhanced angiogenesis and reconstructed renal architecture in vivo, by transplantation into rat models of renal subcapsular and partial nephrectomy. Furthermore, immunofluorescence and single-cell analyses revealed that the hPASCs revascularized bioengineered kidney regenerated both vascular and renal parenchymal cells within the host. This study offers another strategy for kidney bioengineering and regeneration.

bioengineering↗

bioRxiv2025

Translational landscape during Seed Germination at Sub-Codon resolution

Seed germination is crucial for agricultural reproduction. A deep understanding of this process can secure healthy growth at the early phases of plant development and therefore the yield. Recent research indicates that germination is a complex process involving translational regulation. A large group of seed stored mRNAs together with newly synthesized transcripts are regulated by post-transcriptional mechanisms and selectively translated at different stages to support the germination process. To investigate the mechanism of translational control, we performed ribosome profiling on mRNAs of distinct physiological stages during Arabidopsis thaliana seed germination. The 3-nucleotide periodicity of the ribosome association on mRNAs identified indicates their translational potential. Dry seeds, in which translation is on hold are characterized by a unique ribosome association landscape with high association at the 5 and 3 UTR, compared to physiological stages that show active translation. Start codon specific stalling of ribosomes in dry seeds is associated with an adenine enriched sequence motif. Throughout germination codons encoding glycine, aspartate, tyrosine and proline are the most frequent ribosome pausing sites. Moreover, the non-coding RNAs which we identified as associated to ribosomes are indeed translated as was revealed by investigating total seed proteome data. Seed specific upstream Open Reading Frames (uORFs) are identified which may be associated to translational control of adaptative response during early seed germination. Altogether, we present a first ribosome profiling analysis across seed germination that illuminates various regulatory mechanisms that potentially contribute to the seeds survival strategy.

plant biology↗

bioRxiv2025

A Hotspot Phosphorylation Site on SHP2 Drives Oncoprotein Activation and Drug Resistance

SHP2 is a phosphatase and a critical mediator of receptor tyrosine kinase (RTK)-driven RAS/mitogen-activated protein kinase (MAPK) signaling. Despite promising preclinical data, SHP2 inhibitors have shown minimal clinical efficacy, with no defined clinical mechanisms of primary resistance. Here, we elucidate phosphorylation of SHP2 at tyrosine 62 (pY62) as a hotspot phosphorylation site in the proteome and RTK-driven tumor types in patients. We demonstrate that SRC family kinases directly phosphorylate SHP2 at Y62, downstream of but not directly phosphorylated by RTKs. Using biochemical and biophysical analyses, we show that SHP2 Y62D enforces an open, active conformation, resulting in constitutive phosphatase activation that is sufficient to activate MAPK signaling and confer resistance to allosteric SHP2 inhibitors. These findings establish that SHP2 pY62 is a phosphorylation hotspot phenocopying mutational activation, a mechanism of primary resistance to SHP2 inhibitors, and a cancer drug target distinct from wildtype SHP2. Statement of significanceThis study identifies phosphorylation of SHP2 at tyrosine 62 (pY62) as a conserved mechanism of resistance to allosteric SHP2 inhibitors. By stabilizing an open, active SHP2 conformation, pY62 phenocopies oncogenic PTPN11 mutations and sustains MAPK signaling across cancer types. These findings redefine SHP2 inhibitor resistance as a phosphorylation-driven, target-intrinsic process, nominate pY62 as a potential biomarker for therapeutic response, and propose phosphorylated SHP2 as a distinct drug target.

cancer biology↗

bioRxiv2025

Enhancing Strain-level Phage-Host Prediction through Experimentally Vali-dated Negatives and Feature Optimization Strategies

BackgroundAccurate prediction of phage-host interactions at the strain level is critical for understanding microbial ecology and for developing phage-based therapeutics. However, existing models are limited by the lack of experimentally validated negative interactions and inconsistencies in data construction strategies. ResultsIn this study, we present a large-scale phage-host interaction dataset comprising 13,000 experimentally verified links between 125 Klebsiella pneumoniae((K. pneumoniae) phages and 104 K. pneumoniae strains. Using this unique resource, we systematically evaluate the impact of negative data construction methods, feature extraction strategies, and machine learning algorithms on predictive performance. We show that randomly generated negatives significantly inflate model accuracy, while models trained on experimental negatives yield more realistic and robust results. Furthermore, protein-derived features outperform DNA-based features across various data conditions. Notably, models using only tail protein sequences achieve performance comparable to those using full-genome sequences, offering a time-efficient alternative without compromising accuracy. Finally, interpretable machine learning reveals amino acid preferences in both phages and hosts that align with known infection mechanisms and suggest novel determinants such as anti-transcriptional proteins. ConclusionsOur findings highlight best practices for constructing high-fidelity strain-level phage-host prediction models. The dataset and insights presented here provide a valuable benchmark for future studies and lay the foundation for more biologically grounded, interpretable modeling frameworks in viromics and microbiome research.

bioinformatics↗

bioRxiv2025

Antigenic and Virological Characteristics of SARS-CoV-2 Variant BA.3.2, XFG, and NB.1.8.1

The emergence of the SARS-CoV-2 saltation variant BA.3.2, which harbors over 50 mutations relative to its ancestral BA.3 lineage, has raised concerns about its potential to drive outbreaks similar to BA.2.86/JN.1. Concurrently, variants such as NB.1.8.1, LF.7.9, XEC.25.1, XFH, and XFG exhibit enhanced growth advantages over LP.8.1.1, necessitating a comparative analysis of their antigenic and virological characteristics. Here, we evaluated the infectivity, ACE2-binding efficiency, and immune evasion of these variants. Pseudovirus assays revealed BA.3.2s robust antibody evasion, including resistance to Class 1/4 monoclonal antibodies; however, its ACE2 engagement efficiency was markedly reduced due to a closed spike conformation, leading to low infectivity. While XFG and LF.7.9 demonstrated strong immune escape associated with A475V and N487D mutations, their reduced receptor-binding efficiency suggested a need for compensatory adaptations. In contrast, NB.1.8.1 retained high ACE2 affinity and humoral immune evasion, supporting its potential for future dominance. Collectively, BA.3.2s current profile limits its ability to compete with emerging variants like NB.1.8.1. Sustained monitoring of BA.3.2s evolution-- particularly for mutations stabilizing an open RBD conformation or enhancing escape from Class 1 antibodies--is essential to assess its outbreak potential.

immunology↗

bioRxiv2025

Targeting mTORC2 in lung squamous cell carcinoma improves anti-tumor immunity through the PSGL-1-VISTA axis

Targeted therapies have improved survival for lung adenocarcinoma patients. However, similar advances are lacking for lung squamous carcinoma (LUSC). Advances in immunotherapy have shown some promise, but the overall response rate remains low in LUSC. Here, we demonstrate that the mTORC2 signaling pathway represents an actionable target in LUSC to improve anti-tumor immune responses. We show that genetic alterations affecting the mTORC2 pathway are common among patients with LUSC tumors, and targeting mTORC2 reduces LUSC tumor growth in mouse models. Transcriptomics reveal that mTORC2-deficient LUSC cells exhibit reduced expression of glycolytic and hypoxia-related genes. In agreement, loss of mTORC2 signaling decreases lactate levels in tumor-interstitial fluid, creating reduced acidity within the tumor microenvironment. Interestingly, mTORC2-deficient LUSC cells also exhibited reduced expression of the pH-sensitive VISTA ligand PSGL-1 in a HIF-2 dependent mechanism. LUSC patients, but not those with LUAD, display a positive correlation in expression between HIF-2 and PSGL-1, suggesting a distinct association among mTORC2, HIF-2, and immune responses in LUSC. Indeed, mTORC2 loss-of-function enhanced CD8+ T cell activation in tumors, while use of anti-VISTA immunotherapy reduced LUSC tumor burden only in the presence of intact mTORC2 signaling. Collectively, these data describe an important role of mTORC2 signaling in LUSC tumors and demonstrate the therapeutic potential of targeting the mTORC2/PSGL-1/VISTA axis in patients that are non-responsive to current therapies.

cancer biology↗

bioRxiv2025

The multiomics landscape of small peptides encoded by long non-coding RNA-derived sORFs in rice

Long non-coding RNAs (lncRNAs), representing the non-coding RNA regions, constitute a significant portion of the genomes in complex organisms. Recent studies suggest that some lncRNAs have the capability to encode peptides. However, the presence of the lncRNA-derived sORFs-encoded polypeotides (LSEPs) in plants is not well understood. In this study, we developed a multi-omics approach that encompasses transcriptomics, translatomics (Ribo-seq), and proteomics to identify of LSEPs in rice. Among the 2764 identified lncRNAs, 42.69% were found to be bound by the ribosome, indicating a potential for encoding. Optimized small peptide extraction protocol was further developed, and the small peptides from rice leaves were extracted and subjected to LC-MS/MS analysis, leading to the identification of a total of 403 LSEPs across four constructed search databases. This work confirms the peptide-coding ability of lncRNAs in plants. Collectively, our study establishes an efficient multi-omics method for identifiying small peptides encoded by lncRNAs, which may be valuable for large-scare screening of LSEPs in plants.

plant biology↗

bioRxiv2025

High-throughput Monoclonal Antibody Screening from Immunized Rabbits via Droplet Microfluidics

The discovery of monoclonal antibodies (mAbs) is critical to advancing therapeutics, diagnostics, and biomedical research. While mouse-derived mAbs dominate current applications, their limitations--short serum half-life, human immunogenicity, and restricted recognition of human-specific antigens--underscore the need for alternative sources. Rabbit-derived mAbs have been gaining significant traction with their superior antigen-binding affinity, broader epitope diversity, and higher yield potential. However, the absence of well-defined surface markers on rabbit B cells has hindered efficient enrichment strategies, limiting the exploration of this valuable antibody repertoire. In this study, we present an integrated workflow that combines magnetic negative selection with high-throughput droplet microfluidics to overcome these barriers. By optimizing a pan B cell enrichment protocol using a tailored antibody cocktail, we achieved a notable boost in IgG secretion and B cell enrichment. Through two complementary droplet-encapsulated assays using particle aggregation for soluble antigens and reporter cells for membrane-bound antigens, we identified target cells capable of secreting high-affinity IgGs. Subsequent sequencing, in vitro antibody production and characterization confirmed the high affinity rate of the discovered antibodies, outperforming rates previously reported. The use of droplet microfluidics streamlines the analysis of rabbit IgG repertoires, providing a robust platform for rabbit single B cell antibody discovery with promising applications in precision medicines and diagnostics.

molecular biology↗

bioRxiv2025

Structure of an oxygen-induced tubular nanocompartment in Pyrococcus furiosus

Reactive oxygen species (ROS) pose a significant threat to biological molecules, prompting organisms to develop systems that buffer oxidative stress and contain iron, which otherwise amplifies ROS production. Understanding oxidative stress responses requires identifying the key proteins involved and their cellular organization. Here, we combined proteomics and cryo-EM to investigate the response of the anaerobic hyperthermophilic archaeon Pyrococcus furiosus to oxygen exposure. Proteome analysis revealed a significant upregulation of the oxidoreductase Rubrerythrin (Rbr) under oxidative stress. Cryo-electron tomograms showed the formation of prominent oxidative stress-induced tubules (OSITs). Single-particle cryo-EM and mass spectrometry of enriched OSITs identified them as stacked rings of Rbr homotetramers. The 3.3 [A] structure demonstrates that rubredoxin-like domains mediate homotetramer assembly, suggesting that their oxidation drives OSIT formation. Within OSITs, we discovered virus-like particles formed by a ferritin-like/encapsulin fusion protein with iron hydroxide cores, uncovering a sophisticated organelle that protects P. furiosus from ROS through advanced compartmentalization.

molecular biology↗

bioRxiv2025

Sky islands of Southwest China. II: Unraveling hidden species diversity of talpid moles using phylogenomics and skull-based deep learning

The sky islands of Southwest China, characterized by dramatic topographical and climatic variations, are prominent hotspots of biodiversity and endemism. Organisms inhabiting middle-to-high elevation habitats in this region are geographically isolated within distinct mountain chains, which over geological time have been subjected to isolation-by-distance and isolation-by-environment. These processes have led to profound allopatric diversification and strong phylogeographic structuring, resulting in a plethora of genetically distinct cryptic species, as is becoming increasingly evident for many small mammal families. However, morphological conservatism can pose significant challenges in delineating these clades within species complexes. In this study, we leverage artificial intelligence technologies to unravel the hidden species diversity of moles (family Talpidae) in Southwest Chinas sky islands. We first employed ultraconserved elements (UCEs) to investigate the evolutionary history of talpid moles, conducted molecular species delimitation using mitochondrial and multi-locus genes, and utilized both traditional and geometric morphometrics to examine their morphological disparity. To address the challenges of morphology based cryptic species identification, we developed a deep learning Hierarchical Identification of Species NETwork (HIS-NET) to create an image-based model that analyzes four different views of the skull/mandible to distinguish genera and species hierarchically. HIS-NET not only achieved expert-level accuracy in species identification but also effectively distinguished between cryptic and known species, aiding in the identification of key morphological variation intervals. Our results support the recognition of allopatrically distributed taxa in Euroscaptor and Parascaptor as full species, thereby confirming that species diversity in this region remains underestimated. Beyond advancing our understanding of speciation in this unique and fragile ecosystem, our study serves as a proof-of-concept, demonstrating the power of deep learning in unraveling hidden biodiversity within this and other species complexes.

zoology↗

bioRxiv2024

Development of a monoclonal antibody against duck IFN-γ protein and the application for Intracellular Cytokine Staining

ABSTRACTInterferon-{gamma} (IFN-{gamma}), a member of the type II IFN family, is a crucial cytokine in the immune system and serves as an important indicator of immune response. Intracellular Cytokine Staining (ICS) is a technique used to analyze the production of cytokines within individual cells, and it has a wide range of applications in the fields of immunological monitoring, vaccine trials, and the study of infectious diseases. This study aimed to prepare monoclonal antibodies against duck IFN-{gamma} protein and to establish an ICS protocol for detecting the duck IFN-{gamma} protein. The duIFN-{gamma}-His or duIFN-{gamma}-Fc gene was cloned into the pEE12.4 expression vector and expressed as a recombinant protein of size 20.2 KDa or 54.9 KDa in 293F cells. The purified recombinant proteins were inoculated into BALB/c mice to generate splenic lymphocytes capable of secreting anti-duIFN-{gamma} antibodies, and hybridoma cells were obtained after fusion with SP2/0 cells. A new hybridoma cell line named 24H4, which stably secreted IgG3 {kappa} subtype antibody against duck IFN-{gamma}. This monoclonal antibody (mAb) was identified by Western Blot to recognize duck IFN-{gamma} antibodies, and the indirect ELISA results showed that its ability to recognize IFN-{gamma} protein reached 0.001 g/ml. The established ICS method was used to stain PBMCs after ConA stimulation, and duck IFN-{gamma} protein was successfully detected by flow cytometry, indicating that the ICS method was successfully established. This study we use the monoclonal antibody, 24H4, provides a crucial tool for subsequent research on duck cellular immune responses.

immunology↗

bioRxiv2024

Virological and antigenic characteristics of SARS-CoV-2 variants LF.7.2.1, NP.1, and LP.8.1

XEC and KP.3.1.1 have surpassed KP.3 to become the globally dominant lineages due to their unique NTD mutations. However, several emerging JN.1 sublineages, such as LF.7.2.1, MC.10.1, NP.1, and, especially, LP.8.1, have demonstrated superior growth advantages compared to XEC. It is critical to access the virological and antigenic characteristics of these emerging SARS-CoV-2 variants. Here, we found that LF.7.2.1 is significantly more immune invasive than XEC, primarily due to the A475V mutation, which enabled the evasion of Class 1 neutralizing antibodies. However, LF.7.2.1s weak ACE2 binding affinity substantially impaired its fitness. Likewise, MC.10.1 and NP.1 exhibited strong antibody immune evasion due to the A435S mutation, but their limited ACE2 engagement efficiency restricted their growth advantage, suggesting that A435S may regulate the Spike conformation, similar to the NTD glycosylation mutations found in KP.3.1.1 and XEC. Most importantly, we found that LP.8.1 showed comparable humoral immune evasion to XEC but demonstrated much increased ACE2 engagement efficiency, supporting its rapid growth. These findings highlight the trade-off between immune evasion and ACE2 engagement efficiency in SARS-CoV-2 evolution, and underscore the importance of monitoring LP.8.1 and its descend lineages.

immunology↗

bioRxiv2024

The dual ubiquitin binding mode of SPRTN secures rapid spatiotemporal proteolysis of DNA-protein crosslinks

DNA-protein crosslinks (DPCs) are endogenous and chemotherapy-induced genotoxic DNA lesions and, if not repaired, lead to embryonic lethality, neurodegeneration, premature ageing, and cancer. DPCs are heavily polyubiquitinated, and the SPRTN protease and 26S proteasome emerged as two central enzymes for DPC proteolysis. The proteasome recognises its substrates by their ubiquitination status. How SPRTN protease, an essential enzyme for DPC proteolysis, achieves specificity for DPCs still needs to be discovered. We found that the N-terminal SPRTN catalytic region (SprT) possesses a ubiquitin-binding domain named the Ubiquitin interface of SprT Domain (USD). Using multiple biochemical, biophysical, and structural approaches, we reveal that USD binds ubiquitin chains. SPRTN binding to ubiquitin chains via USD leads to [~] 67-fold higher activation of SPRTN proteolysis towards polyubiquitinated DPCs than the unmodified DPCs. This study reveals the ubiquitination of DPCs is the key signal for SPRTNs substrate specificity and rapid proteolysis.

biochemistry↗

bioRxiv2024

A tumor-secreted protein utilizes glucagon release to cause host wasting

Tumor-host interaction plays a critical role in malignant tumor-induced organ wasting across multiple species. Despite known regulation of regional wasting of individual peripheral organs by tumors, whether and how tumors utilize critical host catabolic hormone(s) to simultaneously induce systemic host wasting, however, is largely unknown. Using the conserved yki3SA-tumor model in Drosophila, we discovered that tumors increase the production of adipokinetic hormone (Akh), a glucagon-like catabolic hormone, to cause systemic host wasting, including muscle dysfunction, lipid loss, hyperglycemia, and ovary atrophy. We next integrated RNAi screening and Gal4-LexA dual expression system to identify that yki3SA-gut tumors secrete Pvf1 to remotely activate its receptor Pvr in Akh-producing cells (APCs), ultimately promoting Akh production. The underlying molecular mechanisms involved the Pvf1-Pvr axis that triggers Mmp2-dependent ECM remodeling of APCs and enhances innervation from the excitatory cholinergic neurons. Interestingly, we also confirmed the similar mechanisms governing tumor-induced glucagon release and organ wasting in mammals. Blockade of either glucagon or PDGFR (homolog of Pvr) action efficiently ameliorated organ wasting in the presence of malignant tumors. Therefore, our results demonstrate that tumors remotely promote neural-associated Akh/glucagon production via Pvf1-Pvr axis to cause systemic host wasting.

physiology↗

bioRxiv2024

Enhanced immune evasion of SARS-CoV-2 KP.3.1.1 and XEC through NTD glycosylation

KP.3.1.1 has surpassed KP.3 to become the new globally dominant strain, while XEC, a recombinant variant of KS.1.1/KP.3.3, is rapidly expanding across Europe and North America. Notably, both variants carry mutations, S31del of KP.3.1.1 and T22N of XEC, that could introduce new N-linked glycans on the Spike N-terminal domain (NTD), emphasizing the urgent need to assess their potential changes in viral characteristics. Here, we found that both KP.3.1.1 and XEC maintained the high ACE2-Spike binding affinity and pseudovirus infectivity of KP.3. Importantly, compared to KP.3, KP.3.1.1, and especially XEC, could further evade the neutralizing antibodies in convalescent plasma, even those elicited by KP.2-like breakthrough infections. Interestingly, both variants demonstrated increased resistance against monoclonal neutralizing antibodies targeting various epitopes on the receptor-binding domain (RBD). These suggest that the additional NTD glycosylation of KP.3.1.1 and XEC could enhance immune evasion via allosteric effects, and supports the future prevalence of XEC.

immunology↗