Biology subjects

Liang, K.

Publications and source records attributed to Liang, K..

At least 19 recordsLinked to original sources

bioRxiv2026

Population-scale dietary signatures of the oral microbiome

Diet is an environmental factor that influences oral microbial communities. How specific foods, nutrients and dietary patterns relate to microbial diversity, species composition and functional potential remains incompletely characterised. Here, we combined detailed dietary records with buccal metagenomic profiles from 5,824 Human Phenotype Project participants. Using these data, we examined diet-oral microbiome associations with prediction models and covariate-adjusted analyses. Plant-based and guideline-based dietary patterns showed similar associations across oral microbial species. However, species within the same genus could show opposite associations with a dietary pattern. For example, a whole-food plant-based diet score was positively associated with Streptococcus sanguinis but negatively with S. gordonii and S. oralis. Some diet-oral microbiome associations were replicated at the genus level in an independent US National Health and Nutrition Examination Survey cohort of 4,667 participants. We map dietary associations with oral microbial diversity, species composition and functional potential, revealing shared microbial signatures across dietary patterns.

microbiology↗

bioRxiv2026

Immune Reconstitution and Antigenic Exposure History Shape Virus-Specific Humoral Immunity in People with HIV

CD4+ T-cell recovery is widely used to assess immune reconstitution in people with HIV, but its relationship to virus-specific humoral immunity across pathogens remains unclear. We characterized neutralizing activity against SARS-CoV-2, HIV-1, and influenza viruses in ART-treated, virologically suppressed individuals spanning distinct CD4+ T-cell levels. BA.5 was the dominant SARS-CoV-2 neutralization target across CD4 strata, whereas D614G neutralization increased with greater immune reconstitution. This gradient was largely absent for the antigenically divergent NB.1.8.1 and XFG variants. HIV-1 neutralization was inversely associated with CD4+ T-cell count, while influenza showed strain-dependent patterns. Neutralization-to-protection bridging preserved a CD4-associated gradient for D614G but not for highly immune-evasive variants. These findings show that immune reconstitution does not translate uniformly into antiviral humoral function. Instead, antibody profiles reflect host immune status, prior antigenic exposure, and viral antigenic evolution, supporting pathogen-specific functional assessment alongside conventional immune monitoring.

immunology↗

bioRxiv2026

Daikenchuto modulates gut microbial metabolism to mitigate irinotecan-induced enterotoxicity

Gut microbiota metabolic remodeling is a pivotal determinant in irinotecan-induced enterotoxicity and epithelial damage, although the underlying mechanisms remain unclear. Herein, we discovered that Daikenchuto (DKT), a traditional Chinese prescription for intestinal disorders, alleviated irinotecan-induced enterotoxicity without compromising its anti-tumor efficacy by improving weight loss, diarrhea, intestinal inflammation, and barrier damage, and these effects were partially dependent on gut microbiota. DKT significantly restored microbial tryptophan metabolism in irinotecan-treated rats, which was characterized by the enrichment of Limosilactobacillus reuteri, and elevated levels of indole-3-ethanol (IE) and indole-3-propionic acid (IPA). Multi-omics analysis further revealed a positive correlation between L. reuteri and IE and IPA. Consistent with this, DKT promoted L. reuteri proliferation, leading to the conversion of tryptophan to IE and IPA, which improved epithelial barrier damage in the irinotecan-treated Caco-2 cells. In addition, DKT suppressed the growth of Loop 1 {beta}-glucuronidase ({beta}-GUS)-producing bacteria, such as Escherichia coli. Furthermore, the main constituents of DKT selectively inhibited Loop 1 {beta}-GUS activity independent of the gut microbiota, which reduced the intra-luminal level of 7-ethyl-10-hydroxycamptothecin, the toxic metabolite of irinotecan. Taken together, this study reveals a dual gut microbiota-driven mechanism by which DKT mitigates irinotecan-induced enterotoxicity, which provides a promising strategy for managing chemotherapy-related enterotoxicity.

pharmacology and toxicology↗

bioRxiv2026

Mutation-Resolved Drug Sensitivity Atlas Reveals Broad RAS(ON) Inhibitor Vulnerabilities and a STAT3 Co-Dependency in NRAS-Mutant Melanoma

NRAS-mutated melanoma remains a major unmet clinical need, with no approved targeted therapy and rapid progression on standard treatment. Tri-complex RAS(ON) inhibitors such as daraxonrasib (RMC-6236) and RMC-7977 have shown early clinical activity, but the mutation-specific sensitivity landscape and adaptive resistance programs in melanoma remain undefined. To address this, we generated an isogenic 3D melanoma platform and performed a saturation mutagenesis screen across 95 NRAS missense variants (>99% of clinically recurrent variants), profiling oncogenic fitness and responses to six RAS-targeting agents in spheroids and xenografts. RMC-6236 and RMC-7977 showed the broadest activity and stratified recurrent NRAS mutants into hypersensitive (G12 variants and Q61R/K/L; [~]95% of cases), moderately sensitive (G13D/R/V; [~]4%), and resistant (G60E and Q61P; [~]1%) classes. Structural analyses supported distinct mechanisms underlying reduced susceptibility in a restricted subset of variants. In sensitive genotypes, RAS(ON) inhibition elicited an adaptive cytokine- and RTK-associated survival program converging on STAT3. Co-inhibition of STAT3 enhanced apoptosis, suppressed MYC, and induced tumor regression in NRAS-mutant melanoma models. Together, these findings define a mutation-resolved therapeutic landscape for NRAS-mutant melanoma and identify adaptive STAT3 signaling as a rational target for combination therapy. Statement of Translational SignificanceNRAS-mutated melanoma lacks effective targeted treatments, and clinical responses to immunotherapy are suboptimal. This study presents the first comprehensive drug sensitivity map across 95 NRAS mutations in melanoma, identifying the pan-RAS(ON) inhibitors RMC-6236 and RMC-7977 as broadly effective agents. Multiple mutants with reduced susceptibility are identified, providing mutation-informed guidance for patient selection and clinical trial stratification. Mechanistic analyses reveal that RTK/cytokine-driven STAT3 activation functions as a key survival pathway under RAS(ON) blockade, and its inhibition markedly enhances the efficacy of pan-RAS(ON) inhibitors. These findings support mutation-guided use of RAS(ON) inhibition and highlight STAT3 co-targeting as a rational strategy to strengthen and prolong therapeutic responses in NRAS-mutated melanoma. Highlights- A functional and therapeutic atlas defines 95 recurrent and nonrecurrent NRAS missense variants in melanoma - RMC-6236 and RMC-7977 show broad but genotype-selective activity across major NRAS mutations - A restricted subset of recurrent NRAS mutants shows reduced susceptibility to RAS(ON) inhibition - RAS(ON) inhibition induces an adaptive STAT3 survival program that is therapeutically targetable

cancer biology↗

bioRxiv2025

Armoring STEAP1 CAR T cells with IL-18 potentiates antitumor activity in Ewing sarcoma

BackgroundEwing sarcoma (EwS) is a highly aggressive cancer driven by the EWS::FLI1 fusion oncoprotein affecting children, adolescents, and young adults. Six transmembrane epithelial antigen 1 (STEAP1) is a cell surface antigen transcriptionally controlled by EWS::FLI1 that is broadly expressed in EwS, positioning it as a rational immunotherapy target. However, translating CAR T therapy to solid tumors requires overcoming barriers to potency while maintaining safety. MethodsAnalyses of transcriptome and proteome data were performed to evaluate the effects of EWS::FLI1 perturbation on STEAP1 expression at the transcript and protein levels in EwS models. STEAP1 expression was validated in EwS patient tissues by immunohistochemistry. Second-generation STEAP1-BB{zeta} CAR T cells were tested in orthotopic and disseminated EwS xenograft models. To enhance antitumor activity, an IL-18-armored STEAP1 CAR was engineered. Dose-dependent therapeutic efficacy and safety were evaluated through measurement of tumor burden, survival, and observation for gross toxicities. ResultsSTEAP1 was expressed in [~]97% of primary EwS tumors and directly associated with EWS::FLI1 fusion protein expression in EwS cell lines. In orthotopic EwS models, STEAP1 CAR T cells induced complete tumor regression at 5 x 106 cells. In disseminated disease models, responses were dose-dependent with no evidence of antigen loss. Notably, IL-18 armored STEAP1 CAR T cells achieved complete responses in [~]80% of mice at a reduced dose of 106 cells without overt toxicity. ConclusionsThese data establish STEAP1 as a clinically relevant and highly expressed target in EwS and demonstrate that IL-18 armoring significantly improves CAR T cell efficacy by enhancing potency evident through antitumor activity at reduced cell dose. STEAP1 CAR T cells are currently under evaluation in a first-in-human phase 1/2 dose-escalation clinical trial for metastatic castration-resistant prostate cancer (NCT06236139) and these studies support future clinical translation of STEAP1 CAR T cell therapy for relapsed/refractory EwS.

cancer biology↗

bioRxiv2025

A cortical signature of very preterm birth across development and its association with neurodevelopmental outcomes

Gestational age plays a crucial role in neurodevelopment, and individuals born very preterm (VPT; <32 weeks gestation) are at elevated risk for cognitive, behavioural and psychiatric problems across the lifespan. Better understanding of the impact of very preterm birth on cortical maturation trajectories could inform mechanistic insights into the origins of these sequelae. Here we compared cortical morphology between VPT individuals and full-term controls in three datasets spanning birth, childhood and adulthood. We identified a consistent cortical signature of VPT birth, characterized by reduced surface area and cortical folding in the frontal, temporal, parietal and insular regions, which persisted across development. Furthermore, in two large infant cohorts, we found that this cortical signature was significantly associated with neonatal clinical factors and with poorer motor outcomes at follow-up, suggesting its potential as a neuroimaging marker for long-term neurodevelopmental risk. Given that early motor development plays a key role in shaping infants interactions with the environment and supporting later cognitive and behavioural development, our findings provide insights into the neurobiological pathways linking VPT birth to subsequent neurodevelopmental difficulties.

neuroscience↗

bioRxiv2025

Chemo-mechanotherapy of fibrosis: dynamic control of biological materials through tissue-architecture-dependent crosslink disruption

Extracellular matrix (ECM) stiffness drives cell fate, but tissues are nonlinear and difficult to modify chemically without harming patients. Here, we show that nonlinear mechanical responses of fibrous and porous tissues can be controlled by mechanically modulating crosslinks. Through integrated in vivo, in vitro, and computational approaches, we found that physiological dynamic stretching disrupts pathological advanced glycation end-product (AGE) crosslink-induced fibrogenesis in an architecture-dependent manner. This was effective in lung-like porous scaffolds but not in liver-like fibrous matrices, revealing a critical structure-property relationship. Computational and in vitro models established that this modulates cell-ECM feedback, and that controlling mechanical crosslinking modulates key nonlinearity of networked solids. This discovery inspired a non-invasive, "mechanotherapuetic" ventilation protocol, which reversed pulmonary fibrosis in mice by physically disrupting ECM pathological crosslinks. The therapeutic efficacy was further amplified when combined with pharmacological AGE inhibition. These findings establish design principles for dynamically reprogrammable biological materials and mechano-targeted therapies.

bioengineering↗

bioRxiv2025

T cell AIM2 Exacerbates Lung Inflammation in OVA-LPS and HDM-induced Asthma Models

Asthma is a complex airway inflammatory disease characterized by immune dysregulation, with diverse cellular contributors to inflammation that result in airway hyperresponsiveness (AHR) and excessive immune responses. The role of the inflammasome in asthma is conflicted. AIM2 is an innate immune receptor that activates the inflammasome through DNA binding. The clinical relevance of AIM2 in asthma is supported by analysis of blood or endobronchial biopsies from patients with severe asthma, showing increased AIM2 but not NLRP3 expression. We investigated the role of AIM2 in allergic asthma using ovalbumin (OVA)-LPS and house dust mite (HDM)- induced models. AIM2 expression was elevated in lung homogenates and bronchoalveolar lavage fluid (BALF) cells from allergen-induced groups compared to controls. In the OVA-LPS model, deletion of Aim2 led to reduced airway smooth muscle actin expression and DNA damage, contributing to decreased AHR and lung inflammation in whole body Aim2-/- mice. Surprisingly, cell-specific deletion in CD4+ T cells but not regulatory T cells or myeloid cells significantly affected AHR, indicating AIM2 in CD4+ T cells is a main driver of pathogenesis. Additionally, in HDM-induced asthma, Aim2-/- mice also exhibited reduced AHR. Cell-specific deletion reveals that AIM2 in CD4+ T cells promotes AHR and cytokine production, while AIM2 in myeloid cells modulates IgG1 levels and IL-13-producing CD4+ T cells, and the percentage of alveolar macrophages in BALF. These findings reveal that AIM2 differentially regulates HDM-induced allergic asthma through distinct exacerbating roles in T cells and myeloid cells, highlighting its potential as a therapeutic target. SignificanceAllergic asthma is a complex, heterogeneous disease characterized by airway inflammation and hyper-responsiveness. AIM2, an inflammasome activated by DNA, has emerged as a critical regulator of inflammatory diseases. In humans, AIM2 expression is elevated in severe asthma. In vivo studies highlight AIM2 as a key modulator of allergic asthma in both OVA-LPS and HDM- induced models. Surprisingly, its functional relevance in both models is mediated by its intrinsic role in T cells, while a modest role in myeloid cells is restricted to the HDM model. AIM2 promotes airway hyper-responsiveness and lung inflammation through enhancing type II cytokines, immune subpopulations and DNA damage response. These findings suggest AIM2 as a biomarker and therapeutic target for managing asthma, particularly in severe asthma subtypes.

immunology↗

bioRxiv2025

Differential patterns of cortical expansion in fetal and preterm brain development

The human cerebral cortex undergoes a complex developmental process during gestation, characterised by rapid cortical expansion and gyrification. This study investigates in vivo cortical growth trajectories using longitudinal MRI data from fetal and preterm cohorts. We employed anatomically constrained multimodal surface matching (aMSM) to quantify cortical surface area expansion and compare in-utero versus ex-utero cortical growth using cortical surface data from 22 to 44 weeks post-menstrual age (PMA), acquired as part of the Developing Human Connectome Project (dHCP). Our findings revealed distinct regional and temporal growth patterns during the 2nd and 3rdrd trimesters of healthy fetal cortical expansion. Ex utero brain development following preterm birth was shown to follow a modified trajectory compared to normal gestation, with potential implications for cortical organisation. Our methodology, combining biomechanically constrained surface registration with high quality fetal and neonatal imaging, provides a powerful framework for understanding early cortical development and deviations associated with preterm birth.

neuroscience↗

bioRxiv2025

Motifs of brain cortical folding from birth to adulthood: structural asymmetry and folding-functional links

Cortical folding of brain is widely regarded as an interplay between genetic programming and biomechanical forces, closely linked to cytoarchitectonic regionalisation. Abnormal folding patterns are frequently observed in neurodevelopmental conditions and psychiatric disorders. However, significant inter-individual variability of secondary and tertiary folds obscures detection of shape biomarkers and confounds investigation of folding-functional relationships. Here we investigate cortical folding heterogeneity at fine scale, using novel hierarchical surface registration (MSM-HT) to parse cortical folding patterns into a representative family of distinct anatomical templates. By applying this technique both to young adults from the Human Connectome Project (HCP) and neonates in the Developing HCP and Brain Imaging in Babies (BIBS) cohorts, we identify and characterize common lobe-wise folding patterns: observing consistency across both age groups, with neonatal samples showing less variation. Crucially, we highlight significant hemispheric asymmetry within the temporal lobe for both adults and neonates, and show that improved correspondence of shape does not translate to improved areal correspondence, affirming previous studies that have pointed to dissociation of folding and functional organisation. This study provides a critical step towards understanding brain asymmetry and complex relationships between folding and function, offering a robust framework to generalise the uncovered cortical folding motifs across datasets and developmental stages.

neuroscience↗

bioRxiv2024

A high-throughput, microplate reader-based method to monitor in vitro HIV latency reversal in the absence of flow cytometry

J-Lat cells are derivatives of the Jurkat CD4+ T cell line that contain a non-infectious, inducible HIV provirus with a GFP tag. While these cells have substantially advanced our understanding of HIV latency, their use by many laboratories in low and middle-income countries is restricted by limited access to flow cytometry. To overcome this barrier, we describe a modified J-Lat assay using a standard microplate reader that detects HIV-GFP expression following treatment with latency-reversing agents (LRAs). We show that HIV reactivation by control LRAs like prostratin and romidepsin is readily detected with dose dependence and with significant correlation and sensitivity to standard flow cytometry. For example, 10 {micro}M prostratin induced a 20.1 {+/-} 3.3-fold increase in GFP fluorescence in the microplate reader assay, which corresponded to 64.2 {+/-} 5.0% GFP-positive cells detected by flow cytometery. Similarly, 0.3 {micro}M prostratin induced a 1.7 {+/-} 1.2-fold increase compared to 8.7 {+/-} 5.7% GFP-positive cells detected. Using this method, we screen 79 epigenetic modifiers and identify molibresib, quisinostat, and CUDC-101 as novel LRAs. This microplate reader-based method offers accessibility to researchers in resource-limited regions to work with J-Lat cells and more actively participate in global HIV cure research efforts. HighlightsO_LIJ-Lat T-cell lines are important to HIV cure research but require flow cytometry C_LIO_LIWe describe a method to work with J-Lat cells using a standard microplate reader C_LIO_LIThis assay can detect control LRAs similar to flow cytometry and discover new LRAs C_LIO_LIThis assay allows low-resourced laboratories to contribute to HIV cure research C_LI

microbiology↗

bioRxiv2024

Non-destructive viability assessment of cancer cell spheroids using dynamic optical coherence tomography with trypan blue validation

3D cell cultures are widely used in biomedical research for the recapitulation of in vivo microenvironments. Viability assessment and monitoring of these intricate conformations remain an open problem as standard cell viability protocols based on colorimetry or microscopy are not directly applicable to intact 3D samples. Optical coherence tomography (OCT) has been explored extensively for subsurface structural and quasi-functional analysis of 3D cell cultures and tissue. Recent studies of dynamic OCT as a source of cellular contrast have found qualitative associations with necrosis in cell spheroids, suggesting potential as a viability marker. We present empirical and validated evidence for dynamic OCT as a quantitative indicator of cell viability in 3D cultures. We analysed over 240 MCF-7 cancer cell spheroids with dynamic OCT and corresponding viability measurements using the trypan blue exclusion assay. Significant effects of common reagents Dimethyl sulfoxide (DMSO) and Phosphate-Buffered Saline (PBS) on OCT readouts were noted. We proposed a regression-based OCT brightness normalisation technique that removed reagent-induced OCT intensity biases and helped improve correspondence to the viability assay. These results offer a quantitative biological foundation for further advances of dynamic OCT as a novel non-invasive modality for 3D culture monitoring.

bioengineering↗

bioRxiv2024

hESCs-derived organoids achieve liver zonation by LSEC modulation

Liver zonation, essential for diverse physiological functions, is lacking in existing organoid models, hindering their ability to recapitulate liver development and pathogenesis. Addressing this gap, we explored the feasibility of achieving zonated organoid by co-culturing human embryonic stem cells (hESCs) derived hepatocytes with hESCs derived liver sinusoidal endothelial cells (LSECs) exhibiting characteristics of either the liver lobules pericentral (PC) or periportal (PP) regions. Introducing zonated LSECs with variable WNT2 signaling subtly regulate hepatocyte zonation, resulting in noticeable metabolic function changes. Considering the lipid metabolism variations in PC and PP organoids, we constructed biomimetic zonated non-alcoholic fatty liver disease (NAFLD) organoids and revealed that glucagon-like peptide-1 receptor agonist (GLP-1RA) target LSECs, but not hepatocytes, indicating potential therapeutic mechanisms of GLP-1RA in NAFLD alleviation. This study highlights the crucial role of non-parenchymal cells in organoids for recapitulating niche heterogeneity, offering further insights for drug discovery and in vitro modeling of organ heterogeneity. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=184 SRC="FIGDIR/small/592562v1_figu1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@1907c9eorg.highwire.dtl.DTLVardef@e5a76borg.highwire.dtl.DTLVardef@152a1dcorg.highwire.dtl.DTLVardef@981f_HPS_FORMAT_FIGEXP M_FIG Graphical AbstractSchematic of hESCs-derived liver zonation organoids C_FIG

bioengineering↗

bioRxiv2024

Enzyme Bioink for the 3D Printing of Biocatalytic Materials

The field of 3D biofabrication faces major challenges on the road to printing fully functional tissues and organs. One of them is adding functionality to the newly formed tissue for replicating an active biochemical environment. Native extracellular matrices sequester numerous bioactive species, making the microenvironment biochemically active. On the other hand, most 3D-printed constructs have limited activity, serving merely as mechanical scaffolding. Here we demonstrate active scaffolding through the integration of biocatalytic enzymes within the bioink. Enzymes are an attractive class of biocompatible and substrate-specific bioactive agents that can improve tissue regeneration outcomes. However, the difficulty in the application remains in providing enzymes at the targeted site in adequate amounts over an extended time. In this work, a durable biocatalytic active enzyme bioink for 3D extrusion-based bioprinting is developed by covalently attaching the globular enzyme horseradish peroxidase (HRP) to a gelatin methacrylate (Gel-MA) biopolymer scaffold. Upon introducing methacrylate groups on the surface of the enzyme, it undergoes photo-crosslinking in a post-printing step with the methacrylate groups of Gel-MA without compromising its activity. As a result, HRP becomes a fixed part of the hydrogel network and achieves higher stability inside the gel which results in a higher concentration and catalytic activity for a longer time than solely entrapping the protein inside the hydrogel. We also demonstrate the cytocompatibility of this enzyme bioink and show its printing capabilities for precise applications in the field of tissue engineering. Our approach offers a promising solution to enhance the bioactive properties of 3D-printed constructs, representing a critical step towards achieving functional biofabricated tissues.

bioengineering↗

bioRxiv2023

Fluorescent Peptide-based Probe for the Detection of Alpha-synuclein Aggregates in the Gut

BackgroundParkinsons disease (PD) is diagnosed clinically by motor symptoms, with no molecular diagnostic test currently available. By the time motor symptoms manifest, significant irreversible neurodegeneration has already occurred, limiting the effectiveness of neuroprotective therapies and drug interventions. Recent identification of pathological alpha-synuclein (-syn) aggregates in the gastrointestinal (GI) tract of prodromal PD patients offer a potential avenue for early disease diagnosis. This study aims to explore specific fluorescence labelling of -syn aggregates in the GI tract using a peptide-based probe for early diagnosis of PD. MethodsWe used primary hippocampal neuronal cells and wild-type mouse tissues with the addition of pre-formed -syn fibrils to identify the most suitable peptide fluorescent probe (P1) for staining -syn aggregates in cells and tissues. We validated the probe labelling in GI tract tissues from three mouse models, including PFF-injected mice and two transgenic PD mouse strains. We quantified labelling accuracy by confocal imaging and protein analysis. ResultsWe found that P1 labelled -syn aggregates with high accuracy (87% in comparison to Serine129-phosphorylated -syn antibody) and high specificity for labelling their aggregated forms over monomeric forms. In GI tract tissues, P1 labelled -syn aggregates across tissue layers (mucosa, sub-mucosa, muscularis externa) and achieved comparable performance to antibody staining. Higher degree of probe labelling was found in older mice due to increased accumulation of -syn aggregates with ageing. Notably, -syn aggregates were readily detectable in the colonic mucosae using P1, indicating the potential use of this probe for early PD diagnosis during colonic examinations like colonoscopy. ConclusionWe have developed a peptide-based fluorescent probe and demonstrated its rapid and specific labelling of -syn aggregates. We highlight the probes ability to label these aggregates rapidly over -syn monomers and survey the abundance of -syn aggregates throughout the entire length of the GI tract. These support the further development of P1 as a specific fluorescent imaging biomarker for colonic -syn aggregates for the early detection of PD.

neuroscience↗

bioRxiv2023

CZ CELLxGENE Discover: A single-cell data platform for scalable exploration, analysis and modeling of aggregated data

Hundreds of millions of single cells have been analyzed to date using high throughput transcriptomic methods, thanks to technological advances driving the increasingly rapid generation of single-cell data. This provides an exciting opportunity for unlocking new insights into health and disease, made possible by meta-analysis that span diverse datasets building on recent advances in large language models and other machine learning approaches. Despite the promise of these and emerging analytical tools for analyzing large amounts of data, a major challenge remains the sheer number of datasets and inconsistent format, data models and accessibility. Many datasets are available via unique portals platforms that often lack interoperability. Here, we present CZ CellxGene Discover (cellxgene.cziscience.com), a data platform that provides curated and interoperable data. This single-cell data resource, available via a free-to-use online data portal, hosts a growing corpus of community contributed data that spans more than 50 million unique cells. Curated, standardized, and associated with consistent cell-level metadata, this collection of interoperable single-cell transcriptomic data is the largest of its kind. A suite of tools and features enables accessibility and reusability of the data via both computational and visual interfaces to allow researchers to rapidly explore individual datasets and perform cross-corpus analysis. This functionality is enabling meta-analyses of tens of millions of cells across studies and tissues and providing global views of human cells at the resolution of single cells.

cell biology↗

bioRxiv2023

Tutorial: guidelines for manual cell type annotation of single-cell multi-omics datasets using interactive software

Assigning cell identity to clusters of single cells is an essential step towards extracting biological insights from many genomics datasets. Although annotation workflows for datasets built with a single modality are well established, limitations exist in annotating cell types in datasets with multiple modalities due to the need for a framework to exploit them jointly. While, in principle, different modalities could convey complementary information about cell identity, it is unclear to what extent they can be combined to improve the accuracy and resolution of cell type annotations. Here, we present a conceptual framework to examine and jointly interrogate distinct modalities to identify cell types. We integrated our framework into a series of vignettes, using immune cells as a well-studied example, and demonstrate cell type annotation workflows ranging from using single-cell RNA-seq datasets alone, to using multiple modalities such as single-cell Multiome (RNA and chromatin accessibility), CITE-seq (RNA and surface proteins). In some cases, one or other single modality is superior to the other for identification of specific cell types, in others combining the two modalities improves resolution and the ability to identify finer subpopulations. Finally, we use interactive software from CZ CELLxGENE community tools to visualize and integrate histological and spatial transcriptomic data.

bioinformatics↗

bioRxiv2023

Quantitative Geometric Modeling of Blood Cells from X-ray Histotomograms of Whole Zebrafish Larvae

Tissue phenotyping is foundational to understanding and assessing the cellular aspects of disease in organismal context and an important adjunct to molecular studies in the dissection of gene function, chemical effects, and disease. As a first step toward computational tissue phenotyping, we explore the potential of cellular phenotyping from 3-Dimensional (3D), 0.74 {micro}m isotropic voxel resolution, whole zebrafish larval images derived from X-ray histotomography, a form of micro-CT customized for histopathology. As proof of principle towards computational tissue phenotyping of cells, we created a semi-automated mechanism for the segmentation of blood cells in the vascular spaces of zebrafish larvae, followed by modeling and extraction of quantitative geometric parameters. Manually segmented cells were used to train a random forest classifier for blood cells, enabling the use of a generalized cellular segmentation algorithm for the accurate segmentation of blood cells. These models were used to create an automated data segmentation and analysis pipeline to guide the steps in a 3D workflow including blood cell region prediction, cell boundary extraction, and statistical characterization of 3D geometric and cytological features. We were able to distinguish blood cells at two stages in development (4- and 5-days-post-fertilization) and wild-type vs. polA2 huli hutu (hht) mutants. The application of geometric modeling across cell types to and across organisms and sample types may comprise a valuable foundation for computational phenotyping that is more open, informative, rapid, objective, and reproducible.

systems biology↗