Biology subjects

Yuan, M.

Publications and source records attributed to Yuan, M..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Directed evolution of a stem-helix targeting antibody enables MERS-CoV cross-neutralization through enhanced binding affinity

Broadly neutralizing antibodies (bnAbs) targeting conserved regions of the betacoronavirus spike are important for pan-betacoronavirus protection and pandemic preparedness. Here, we report on the isolation of a human monoclonal antibody, CC65.1, from a SARS-CoV-2 convalescent donor that targets the conserved S2 stem helix region. CC65.1 neutralizes various sarbecoviruses, including SARS-CoV-2, and binds the MERS-CoV spike but lacks MERS-CoV-neutralizing activity due to insufficient binding affinity. We utilized directed evolution to enhance the binding affinity of CC65.1 for the MERS-CoV S2 stem helix, yielding engineered antibody variants with newly acquired MERS-CoV-neutralizing activity. High-resolution structural analysis reveals key paratope mutations that optimize binding and stabilize epitope engagement. Our findings demonstrate the potential of rational antibody engineering to expand bnAb breadth across divergent betacoronaviruses. This work supports the development of engineered bnAbs and S2-targeted vaccines for broad betacoronavirus countermeasures and highlights strategies to achieve cross-lineage immunity for future pandemic threats. Author SummaryThe persistent emergence of new SARS-CoV-2 variants of concern that evade neutralizing antibody responses and other zoonotic betacoronaviruses with pandemic potential have provided strong motivation to develop broadly neutralizing antibodies (bnAbs) that target more conserved regions of the spike protein in sarbecoviruses and other betacoronaviruses. Here, we employed a directed evolution strategy to engineer the sarbecovirus-neutralizing antibody CC65.1, which targets the conserved S2 stem helix, to enhance its binding affinity with the MERS-CoV stem helix region, thereby conferring MERS-CoV neutralization. High-resolution structural studies of engineered CC65.1 revealed that key mutations reshape the paratope to better accommodate and stabilize the MERS-CoV S2 stem helix, resulting in increased binding affinity and neutralization potency. This study emphasizes the critical role of affinity maturation in expanding neutralization breadth and provides valuable insights for design of bnAbs to prevent and treat pandemic threats by betacoronaviruses.

immunology↗

bioRxiv2025

Reduced legacy precipitation decreases microbial community growth efficiency and alters soil organic carbon in a California grassland

Changes in global patterns can leave a lasting legacy in semi-arid grasslands by reshaping microbial growth dynamics and carbon cycling during the first wet-up in the autumn--a period known for intense microbial activity and significant carbon emissions. To study the lasting impacts of decreased winter rain, we implemented two precipitation regimes (100% vs. 50% mean annual precipitation) in California Mediterranean-climate grassland field plots. After the dry season, soils were rewetted in the laboratory with H218O, and sampled at 0 h, 3 h, 24 h, 48 h, 72 h, and 168 h post rewet. We quantified CO2 efflux; measured microbial growth and mortality via quantitative 18O stable isotope probing and 16S rRNA gene amplicon sequencing; and characterized the soil organic carbon chemical composition, metagenomes, and metatranscriptomes. We found that reduced winter precipitation imposed a strong legacy effect on microbial turnover; despite maintaining similar respiration rates, microbial growth declined by [~]1 order of magnitude, yielding decreased community growth efficiency (CGE = gross community growth/net respiration), and microbial mortality declined by [~]2 orders of magnitude. Soil organic carbon also shifted from lipid-like, amino-sugar-like, and protein-like compounds (indicative of microbial necromass) to more oxidized lignin-like and tannin-like compounds (indicative of decomposing plant-derived compounds). Meta-omics revealed distinct metabolic strategies linked to CGE. At high-CGE, microbes appeared to consume more energetically favorable N-rich necromass (released via high microbial turnover), this allowed for increased amino acids and peptidoglycan biosynthesis and greater aromatic compound degradation, fueling further energy production and growth efficiency. At low-CGE, communities had elevated carbohydrate metabolism and lipid turnover, consistent with increased investment in plant detritus degradation and membrane repair and maintenance rather than growth. Together, our findings demonstrate that reduced winter rainfall decreases microbial turnover following rewetting. Persistent decreases in CGE due to reduced winter rainfall result in consistent carbon loss as CO2, which, if sustained over multiple years, could ultimately lead to a net decline in total soil organic carbon.

microbiology↗

bioRxiv2025

Therapeutic Potential of a Tectorigenin Derivative (TED) in Herpetic Stromal Keratitis: Antiviral and lmmunomodulatory Mechanisms

ObjectivesIn this study, the anti-HSV-1 effects of TED were investigated in vitro and in vivo, its therapeutic efficacy against herpetic stromal keratitis (HSK) was evaluated, and its mechanism of action was examined. MethodsWe assessed the cytotoxicity and anti-HSV-1 activity of TED in Vero cells using CCK-8 and plaque assays. The HSK model mice received TED (2.5, 5, or 15 mg/kg), and symptom progression was monitored. The therapeutic effects were evaluated through HE staining, corneal immunofluorescence, and HSV-1 gB quantification. Mechanistic studies were performed to examine the expression of TLR pathway genes, CD4+/CD8+ T-cell infiltration in the cornea and draining lymph nodes, and dendritic cell activation. ResultsTED showed potent anti-HSV-1 activity in vitro and ameliorated HSK in mice, improving body weight and reducing corneal pathology and the incidence of encephalitis. It decreased HSV-1 loads in the cornea, trigeminal ganglion, and brain while modulating cytokines (downregulating IFN-/{gamma}, TNF-, and IL-1{beta} and upregulating IL-10). TED suppressed the TLR pathway (TLR2/3/9, TRAF6, IRF3, and NF-{kappa}B) in the corneal epithelium and reduced CD4+/CD8+ T-cell and dendritic cell infiltration while increasing the number of CD4+ T cells in the lymph nodes. ConclusionsTED has significant anti-HSV-1 activity and effectively treats HSK by reducing viral loads, improving symptoms, and modulating immune responses through TLR pathway inhibition and immune cell regulation, suggesting its potential as an HSK therapeutic.

pharmacology and toxicology↗

bioRxiv2025

Designing smart spatial omics experiments with S2Omics

Spatial omics technologies have transformed biomedical research by enabling high-resolution molecular profiling while preserving the native tissue architecture. These advances provide unprecedented insights into tissue structure and function. However, the high cost and time-intensive nature of spatial omics experiments necessitate careful experimental design, particularly in selecting regions of interest (ROIs) from large tissue sections. Currently, ROI selection is performed manually, which introduces subjectivity, inconsistency, and a lack of reproducibility. Previous studies have shown strong correlations between spatial molecular patterns and histological features, suggesting that readily available and cost-effective histology images can be leveraged to guide spatial omics experiments. Here, we present S2Omics, an end-to-end workflow that automatically selects ROIs from histology images with the goal of maximizing molecular information content in the ROIs. Through comprehensive evaluations across multiple spatial omics platforms and tissue types, we demonstrate that S2Omics enables systematic and reproducible ROI selection and enhances the robustness and impact of downstream biological discovery.

genomics↗

bioRxiv2025

Optimizing Polygenic Scores for Complex Morphological Traits: A Case Study in Nasal Shape Prediction

Polygenic scores (PGS) facilitate the prediction of an individuals phenotype from their genotype. Typically, PGS methods apply regularization or use a clumping and thresholding (C+T) approach to handle SNP inclusion. To achieve good prediction accuracy, these approaches rely on effect size estimates from well-powered genome-wide association studies (GWAS). However, this is currently not feasible for morphological shape when phenotyped as univariate traits. Here, we introduce a novel framework to enhance polygenic prediction through three key components: (1)leveraging multivariate GWAS summary statistics for improved SNP selection, (2) defining genetically informative phenotypes, and (3) benchmarking PGS methods to select the optimal model. Our approach integrates multivariate GWAS, which performs an omnibus test against all phenotypic variables jointly with increased power. Specifically, our approach leverages P values from multivariate GWAS to improve SNP selection while maintaining the effect size estimates for the univariate trait under investigation, allowing the use of current PGS tools. We evaluated our proposed method for predicting 3D nasal morphology using a dataset of 52,896 individuals of European ancestry from the UK Biobank. Using the C+T method, SNP selection based on multivariate GWAS resulted in significantly improved phenotypic prediction (P = 9.74e-5) for eigen-shapes, with a mean variance explained of 3.88% (SD = 1.59%) compared to 2.02% (SD = 1.10%) using a traditional univariate approach in the test set (n = 2,896). We also tested whether heritability-optimized phenotypes were more predictable than eigen-shapes derived from principal component analysis (PCA). On average, with SNP selection based on multivariate GWAS using the C+T method, heritability-optimized phenotypes yielded greater predictive performance, with PGS scores explaining 2.72%-10.37% of phenotypic variance, compared to 1.05%-6.84% for eigen-shapes. Furthermore, benchmarking several PGS methods revealed that LDpred2 consistently achieved the best performance for predicting nasal morphology. Our results demonstrate that combining multivariate GWAS P values with optimized phenotypes and advanced PGS models leads to more accurate polygenic prediction for complex morphological traits.

bioinformatics↗

bioRxiv2025

Apical extracellular matrix regulates fold morphogenesis in the Drosophila wing disc

Tissue folding is a fundamental process occurring often in animal organ development. Here, we study the progression of fold shape and the underlying mechanics in the development of the Drosophila wing disc. We present a 3D segmentation of the apical surface of the wing disc proper from larval stages, when folds grow, to early pupariation, when the tissue unfolds and remodels into a bilayer. We establish morphological metrics to quantify and resolve fold shape in this dataset, introducing a definition of fold depth and width that can be used to characterize folds on a curved surface. Furthermore, we identify fibrous extracellular matrix on the apical side (aECM) that physically connects the two opposing sides of the folds. By modeling a tissue fold with a lateral vertex model endowed by an adhesive layer representing the aECM, we predict that unfolding in the wing disc is preceded by the removal of aECM. Using genetic perturbations, we confirm that aECM adhesion affects fold stability and mechanics: loss of aECM leads to abnormal fold shape and unfolding dynamics, whereas failure to remove aECM at pupariation inhibits unfolding. Finally, we show that these aECM perturbations in larval stages cause morphological phenotypes in the adult wing, demonstrating that the fold morphology of the wing disc helps to define adult wing shape. In total, our work establishes a key mechanical role for aECM in wing disc growth and morphogenesis and advances our general understanding of how epithelial tissue folds can be mechanically stabilized during development.

developmental biology↗

bioRxiv2025

Structural and functional analysis of VYD222: a broadly neutralizing antibody against SARS-CoV-2 variants

Extensive mutations in SARS-CoV-2 spike protein have rendered most therapeutic monoclonal antibodies (mAbs) ineffective. However, here we describe VYD222 (pemivibart), a human mAb re-engineered from ADG20 (adintrevimab), which maintains potency despite substantial virus evolution. VYD222 received FDA Emergency Use Authorization for pre-exposure prophylaxis of COVID-19 in certain immunocompromised adults and adolescents. Here we show potent neutralization of this antibody against a broad range of emerging variants, including Omicron KP.3 and KP.3.1.1. X-ray crystal structures of VYD222 complexed with the receptor-binding domains of prototype SARS-CoV-2 and Omicron BA.5 demonstrate the binding epitope spans from the receptor binding site to the conserved CR3022 site. Notably, many of the matured residues between ADG20 and VYD222 occur outside the paratopic region. Deep mutational scanning indicates that SARS-CoV-2s ability to escape VYD222 is constrained by structural compatibility and the need to maintain receptor binding. These findings provide crucial insights into the escape-resistant neutralization of VYD222 against a broad panel of clinically relevant SARS-CoV-2 variants and offer valuable guidance for risk assessment of emergent variants.

biophysics↗

bioRxiv2025

In Vivo Evolution of Monoclonal Antibody CR3022 to Achieve Cross-Neutralization of SARS-CoV-2 and Implications for Vaccine Strategies Against SARS-Related Viruses

The epitope that monoclonal CR3022 binds to represents a promising target for broad protection against a wide range of human and zoonotic coronaviruses. We developed a powerful model to evaluate antibody affinity maturation in vivo using immunoglobulin (Ig)-humanized mice that express the predicted germline heavy chain of antibody CR3022. SARS-CoV/SARS-CoV-2 sequential immunization led to the convergent evolution of the germline CR3022 through somatic hypermutation (SHM) that resembled the affinity-matured CR3022 from a human, but now also adapted to key variants and divergent sarbecoviruses. While simple prime-boost strategies drove CR3022-epitope targeting, an intensive vaccination protocol elicited dominant responses to other epitopes. X-ray crystal structures revealed that SARS-CoV-2-neutralizing CR3022-like antibodies exhibit enhanced affinity by increasing polar and electrostatic interactions. Overall, these findings show CR3022-like clones can be readily adapted through SHM to increase breadth and potency to sarbecoviruses by relatively minor shifts in affinity with appropriate vaccination strategies.

immunology↗

bioRxiv2025

Hedyotis Diffusae Herba Mitigates Rotenone-Induced Neurotoxicity via Akt Pathway in SH-SY5Y Cells

Hedyotis Diffusae Herba (HDH), known in traditional Chinese medicine for its heat-clearing and detoxifying properties, has been widely used to manage inflammation-related conditions. However, its neuroprotective potential and mechanism in the context of Parkinsons disease (PD) remain unclear.Network pharmacology and molecular docking were applied to predict the interactions between HDH components and PD-associated targets. Molecular dynamics simulations assessed the binding stability of major compounds to core targets. Rotenone-induced SH-SY5Y cell injury served as an in vitro PD model to evaluate HDHs biological effects. Cell viability, reactive oxygen species (ROS), IL-6 secretion, and Akt phosphorylation were assessed by CCK-8 assay, ROS detection kit, ELISA, and western blot, respectively. MK2206, an Akt inhibitor, was used to validate pathway involvement.Seven bioactive compounds were identified in HDH, among which stigmasterol and quercetin exhibited strong binding affinities with AKT1, IL-6, and JUN. Simulations confirmed stable interactions. HDH significantly increased cell viability and decreased intracellular ROS and IL-6 levels in rotenone-treated SH-SY5Y cells. Akt phosphorylation was restored by HDH, and the effect was blocked by MK2206, indicating Akt pathway participation.HDH exerts neuroprotective effects against rotenone-induced toxicity via antioxidant and anti-inflammatory activities and Akt pathway activation. These findings provide mechanistic insight and pharmacological support for HDH as a potential candidate in complementary therapy for PD.

cell biology↗

bioRxiv2025

Loss of vitamin C biosynthesis protects from a parasitic infection

The ability to synthesize essential molecules is sometimes lost in evolution. A classic example is ascorbate (Vitamin C), which is synthesized in most animals by L-Gulonolactone Oxidase (GULO), an enzyme lost multiple independent times in animal evolution. This event is thought to be evolutionarily neutral, however, GULO-deficient animals including humans need to obtain ascorbate from their diet and are susceptible to ascorbate deficiency and scurvy. We therefore hypothesized that this disadvantage of GULO loss is offset by physiological benefits. Here we show that ascorbate deficiency protects mice from schistosomiasis, a debilitating parasitic disease which afflicts 250 million people. Schistosoma mansoni worms required host ascorbate to produce eggs in vivo. Consequently, ascorbate-deficient mice were protected from schistosomiasis pathologies and transmission. Intermittent ascorbate deficiency protected Gulo-deficient mice from both scurvy and schistosomiasis mortality. The effects of ascorbate on schistosome reproduction were mediated by ascorbate-dependent histone demethylation which promoted vitellocyte development in female schistosomes. We propose that vitamin deficiencies are not always detrimental but can protect animals from pathogens which need to obtain vitamins from their host.

biochemistry↗

bioRxiv2025

A Patient-Specific 3D Printed Carotid Artery Model Integrating Vascular Structure, Flow and Endothelium Responses

The progression of atherosclerosis is driven by the interplay between vascular anatomy, hemodynamic forces, and endothelial responses. However, existing in vitro vascular models have yet to integrate all these elements into a cohesive, patient-specific system. Here, we present the first instance of direct 3D printing of a miniaturized, patient-specific carotid artery model that recapitulates anatomical-dependent hemodynamic changes and vascular cell remodeling. Phase-contrast MRI scans from a healthy donor were used to generate miniaturized 3D carotid artery models, which were analyzed via computational fluid dynamics (CFD) and particle imaging velocimetry (PIV) to validate the preservation of physiological hemodynamic properties. Using digital light processing (DLP) 3D printing, we fabricated the miniaturized carotid artery vessel using GelMA, containing embedded human aortic smooth muscle cells and an endothelialized lumen. Perfusion culture replicated physiological arterial shear stress of up to 10 dynes cm-{superscript 2}, resulting in differential endothelial cell alignment and inflammatory monocyte adhesion corresponding to laminar and turbulent flow regions within the carotid artery. This model serves as a powerful platform to investigate how anatomical variation influences susceptibility to atherosclerosis through its impact on local flow dynamics.

bioengineering↗

bioRxiv2025

Improving Multi-Trait Genomic Prediction Efficiency Through The Incorporation Of Synthetic Traits Selected Based on Co-heritability

Genomic prediction (GP) is an essential tool in the field of plant breeding to accelerate the cultivar development pipeline by predicting the performance of unphenotyped lines. The precision of prediction is constrained by the heritability of the target trait when applying a single-trait genomic prediction model. To overcome this limitation, a multi-trait genomic prediction model leveraging high-heritability secondary traits co-heritable with the target trait can boost predictive ability for the target trait. However, this is practically challenging because it requires additional phenotyping effort and prior knowledge of trait co-heritability. This study aimed to assess the efficiency of multi-trait genomic prediction models powered by secondary traits derived from high-throughput phenotyping data when predicting important leaf functional target traits, i.e., nitrogen (N) content and specific leaf area (SLA) in diverse sorghum accessions. Since these traits can be predicted from hyperspectral reflectance data, there is significant potential for other wavelengths within the existing dataset to meet the criteria needed to improve prediction accuracy using multi-trait approaches. Therefore, experiments were performed on traditional direct measures of leaf N content and SLA, plus partial least squares regression predictions of them (Leaf N-PLSR, SLA-PLSR), i.e., four target traits in total. Three secondary, "synthetic traits" (S1, S2, S3), each a ratio of two wavelengths within the hyperspectral data, were identified based on high co-heritability with a given target trait. Single-trait GBLUP (Genomic Best Linear Unbiased Predictor) was fitted as a baseline model, followed by three multi-trait GBLUP models using synthetic traits and target traits together. Model performance was assessed using k-fold (k=5) cross-validation (CV), which consisted of single-trait, CV1, and CV2 schemes. The synthetic traits high genetic correlation and heritability met the requirements for their use as secondary traits. There was a significant increase in accuracy when synthetic traits were used in the multi-trait genomic prediction model compared to a single trait alone for all four target traits. It improved prediction accuracy while using secondary traits derived from hyperspectral high-throughput phenotyping data in the multi-trait genomic prediction model, suggesting that this approach could be broadly applied in a post-hoc fashion to many datasets without any additional phenotyping effort. Our analysis highlights a practical approach to improve multi-trait genomic prediction model performance using synthetic traits with no intrinsic biological meaning selected through co-heritability estimation.

genetics↗

bioRxiv2025

Genomic analysis uncovers unique haplotype signatures from subspecies and agronomic types associated with blanchability in groundnut

Blanchability, defined as the ease of seed coat removal after roasting, is a vital trait for enhancing processing efficiency and product quality in groundnut (Arachis hypogaea L.). To enable a comprehensive haplotype-level genetic dissection of this trait, SNPs derived from whole-genome resequencing (WGRS) were used to perform genome-wide association study (GWAS) using multi-locus models (BLINK and FarmCPU) on a diverse groundnut mini-core collection phenotyped across two crop seasons. A total of 26 significant SNP-trait associations (STAs) were identified across multiple chromosomes, with major loci on chromosomes Ah05, Ah06, and Ah17, some of which were further validated using KASP (Kompetitive Allele-Specific PCR) markers. Candidate genes, such as those involved in cell wall biosynthesis (e.g., galactoside 2-alpha-L-fucosyltransferase-like protein, protein kinase superfamily members, and glycerophosphoryl diester phosphodiesterase 3), were found to be within linkage disequilibrium (LD) of the identified STAs, suggesting their plausible association with blanchability. Haplo-pheno analyses identified superior high-blanchability haplotypes; Ah05HapBL3, Ah06HapBL5, Ah06HapBL10, and Ah17HapBL6, which were predominantly found in the fastigiata subspecies (including Valencia and Spanish bunch agronomic types) from South Asia and South America, while the low-blanchability haplotypes were from hypogaea subspecies (including Virginia runner and Virginia bunch agronomic types) from Africa. Overall, this study provides valuable insights for customizing blanchability through haplotype-based breeding of processing-grade cultivars thereby improving groundnut value chains to meet diverse industrial demands.

genomics↗

bioRxiv2025

AF9/KLF2 gene regulatory circuit links histone lactylation to breast cancer metastasis

Histone lysine L-lactylation (hereafter referred to as histone Kla) is a novel epigenetic mark induced by glycolytic metabolism, serving as a link between metabolic reprogramming and epigenetic regulation. In this study, we uncover an epigenetic-genetic transcriptional regulatory circuit involving AF9 and KLF2 that drives luminal breast cancer progression. AF9, identified as a reader of histone H3 lysine 9 lactylation (H3K9la), promotes KLF2 expression, while KLF2, functioning as a transcription factor for AF9, forms a positive feedback loop that amplifies lactylation-dependent effects. This circuit activates tumor-associated pathways, including TGF{beta}1, glucose and lactate transporters, and metabolic enzymes essential for glycolysis and serine biosynthesis, driving tumorigenesis and metastasis. Spatial and single-cell transcriptomics show AF9-positive tumor cells enriched in regions of active lactylation, correlated with immune evasion through interactions with M2 macrophages. Together, AF9, H3K9la, and KLF2 integrate metabolism, epigenetics, and signaling to promote tumor growth and metastasis, highlighting AF9s central role as a histone lactylation reader and a potential therapeutic target in breast cancer. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/660498v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@56b216org.highwire.dtl.DTLVardef@1c5cbc1org.highwire.dtl.DTLVardef@c42a5corg.highwire.dtl.DTLVardef@b912ec_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Cis-regulation of gene expression between sexes and life stages in Rumex hastatulus

The potential for conflict between sexes and life stages while sharing predominantly the same genome has important evolutionary consequences. In dioecious angiosperms, genes beneficial for the haploid pollen stage may reduce the fitness of diploid offspring of both males and females. However, we still lack an understanding of the extent of shared genetic architecture for gene expression between the sexes or life stages in plants, a key component for predicting the potential for conflict. We performed expression quantitative trait loci (eQTL) mapping to test if standing variation affects sexes and life stages differently using a population sample of the dioecious outcrossing plant Rumex hastatulus. We compared effect sizes and allele frequencies of cis-eQTLs in male and female leaf tissues and pollen and tested for genotype-by-sex interactions for gene expression. We found stronger shared genetic architecture between sexes than between life stages, suggesting greater potential for ongoing sexual conflict in leaves, which have been shown to be sexually dimorphic in earlier studies. In contrast, conflict over optimal gene expression between pollen and leaves may be easily resolved due to their distinct genetic architectures. Additionally, our burden of rare allele test suggested a signature of stabilizing selection against extreme gene expression in leaves. Our study highlights the use of eQTLs to investigate selection on gene expression and the evolution of conflict between sexes and life stages in dioecious species.

evolutionary biology↗

bioRxiv2025

Structural insights into VRC01-class bnAb precursors with diverse light chains elicited in the IAVI G001 human vaccine trial

The development of germline-targeting vaccines represents a potentially transformative strategy to elicit broadly neutralizing antibodies (bnAbs) against HIV and other antigenically diverse pathogens. Here, we report on structural characterization of vaccine-elicited VRC01-class bnAb precursors in the IAVI G001 Phase 1 clinical trial with the eOD-GT8 60mer nanoparticle as immunogen. High-resolution X-ray structures of eOD-GT8 monomer complexed with Fabs of five VRC01-class bnAb precursors with >90% germline identity revealed a conserved mode of binding to the HIV CD4-binding site (CD4bs) via IGHV1-2-encoded heavy chains, mirroring mature bnAb interactions. The light-chain V-gene diversity emulated VRC01 bnAbs and stabilized antigen engagement, while their conserved five-residue LCDR3 motifs prevented steric clashes. Notably, the VRC01-class bnAb precursors accommodated the N276 glycan, a key barrier in HIV Env recognition, through structural rearrangements in HCDR3 or LCDR1, despite its absence in the immunogen. Surface Plasmon Resonance (SPR) analysis showed that 87% of elicited antibodies retained glycan binding capacity, albeit with reduced affinity. These findings validate the ability of eOD-GT8 60mer nanoparticles to prime VRC01-class bnAb precursors with native-like paratopes but with intrinsic glycan adaptability. Structural mimicry of mature bnAbs was observed even with limited somatic hypermutation, indicating that critical features are encoded in the germline repertoire. The structures highlight how germline-encoded features drive bnAb-like recognition at early stages. This work provides molecular evidence supporting germline-targeting in humans and provides guidance for designing booster immunogens to shepherd affinity maturation toward broad neutralization.

immunology↗

bioRxiv2025

Diversity, connectivity and negative interactions define robust microbiome networks across land, stream, and sea

In this era of rapid global change, factors influencing the stability of ecosystems and their functions have come into the spotlight. For decades the relationship between stability and complexity has been investigated in modeled and empirical systems, yet results remain largely context dependent. To overcome this we leverage a multiscale inventory of fungi and bacteria ranging from single sites along an environmental gradient, to habitats inclusive of land, sea and stream, to an entire watershed. We use networks to assess the relationship between microbiome complexity and robustness and identify fundamental principles of stability. We demonstrate that while some facets of complexity are positively associated with robustness, others are not. Beyond positive biodiversity x robustness relationships we find that the number of "gatekeeper" species or those that are highly connected and central within their networks, and the proportion of predicted negative interactions are universal indicators of robust microbiomes. With the potential promise of microbiome engineering to address global challenges ranging from human to ecosystem health we identify properties of microbiomes for future experimental studies that may enhance their stability. We emphasize that features beyond biodiversity and additional characteristics beyond stability such as adaptability should be considered in these efforts.

ecology↗

bioRxiv2024

High-Throughput Targeted Drug Screening for NF1-associated High-Grade Gliomas with ATRX Deficiency

Neurofibromatosis type 1 (NF1)-associated high-grade gliomas (HGGs) harboring ATRX mutations exhibit an aggressive clinical phenotype, driven by heightened genomic instability and metabolic reprogramming. Existing therapies, including chemotherapy and radiotherapy, are limited by resistance mechanisms and formation of secondary malignancy, underscoring the need for novel therapeutic strategies. Here, we report the results of a high-throughput screening of 10,000 small molecules aimed at identifying compounds selectively targeting vulnerabilities associated with concurrent ATRX and NF1 loss. Among the screened compounds, K784-6195 (ChemDiv ID) emerged as a promising candidate, exhibiting marked selective cytotoxicity in NF1-associated glioma cell lines with ATRX deficiency (IC50 = 4.84 {micro}M). In comparison, wild-type ATRX sporadic glioma cell lines (U251) exhibited significantly reduced sensitivity to K784-6195 (IC50 = 37.03 {micro}M). However, ATRX knockout U251 glioma cells recapitulating concurrent ATRX and NF1 loss exhibited heightened susceptibility to K784-6195 (IC50 = 20-23 {micro}M) compared to their wild-type counterpart. Metabolomic analysis revealed that K784-6195 treatment impairs metabolic pathways, including the pentose phosphate pathway, glutamine metabolism, and redox homeostasis, leading to oxidative stress and impaired cell survival. These findings highlight K784-6195 as a promising candidate for therapeutic development, offering a targeted approach for the treatment of NF-1 associated HGGs with ATRX deficiency.

cancer biology↗