bioRxiv Science⌕ Search

Biology subjects

Wang, C.

Publications and source records attributed to Wang, C..

At least 757 records · Page 42Linked to original sources

Omicron-specific mRNA vaccine elicits potent immune responses in mice, hamsters, and nonhuman primates

SARS-CoV-2 has infected more than 400 million people around the globe and caused millions of deaths. Since its identification in November 2021, Omicron, a highly transmissible variant, has become the dominant variant in most countries. Omicrons highly mutated spike protein, the main target of vaccine development, significantly compromises the immune protection from current vaccination. We develop an mRNA vaccine (SOmicron-6P) based on an Omicron-specific sequence. In mice, SOmicron-6P shows superior neutralizing antibodies inducing abilities to a clinically approved inactivated virus vaccine, a clinically approved protein subunit vaccine, and an mRNA vaccine (SWT-2P) with the same sequence of BNT162b2 RNA. Significantly, SOmicron-6P induces a 14.4[~]27.7-fold and a 28.3[~]50.3-fold increase of neutralizing activity against the pseudovirus of Omicron and authentic Omicron compared to SWT-2P, respectively. In addition, two doses SOmicron-6P significantly protects Syrian hamsters against challenge with SARS-CoV-2 Omicron variant and elicits high titers of nAbs in a dose-dependent manner in macaques. Our results suggest that SOmicron-6P offers advantages over current vaccines, and it will be helpful for those with weak immunity.

microbiology↗

The chromatin landscape of Th17 cells reveals mechanisms of diversification of regulatory and pro-inflammatory states

Th17 cells are a heterogenous cell population consisting of non-pathogenic Th17 cells (npTh17) that contribute to tissue homeostasis and pathogenic Th17 cells (pTh17) that are potent mediators of tissue inflammation. To reveal regulatory mechanisms underlying Th17 heterogeneity, we performed combined ATAC-seq and RNA-seq and discovered substantial differences in the chromatin landscape of npTh17 and pTh17 cells both in vitro and in vivo. Compared to other CD4+ T cell subsets, npTh17 cells share accessible chromatin programs with Tregs, and pTh17 cells have an intermediate profile spanning features of npTh17 cells and Th1 cells. Integrating single-cell ATAC-seq and single-cell RNA-seq, we inferred self-reinforcing and mutually exclusive regulatory networks controlling the different cell states and predicted transcription factors (TFs) shaping the chromatin landscape of Th17 cell pathogenicity. We validated one novel TF, BACH2, which promotes immunomodulatory npTh17 programs and restrains pro-inflammatory Th1-like programs in Th17 cells and showed genetic evidence for protective variants in the human BACH2 locus associated with multiple sclerosis. Our work uncovered mechanisms that regulate Th17 heterogeneity, revealed shared regulatory programs with other CD4+ T cell subsets, and identified novel drivers of Th17 pathogenicity as potential targets to mitigate autoimmunity.

immunology↗

Single-cell Gene Regulation Network Interference by Large-scale Data Integration

Single-cell ATAC-seq (scATAC-seq) has proven to be a state-of-art approach to investigating gene regulation at the single-cell level. However, existing methods cannot precisely uncover cell-type-specific binding of transcription regulators (TRs) and construct gene regulation networks (GRNs) in single-cell. ChIP-seq has been widely used to profile TR binding sites in the past decades. Here, we developed SCRIP, an integrative method to infer single-cell TR activity and targets based on the integration of scATAC-seq and a large-scale TR ChIP-seq reference. Our method showed improved performance in evaluating TR binding activity compared to the existing motif-based methods and reached a higher consistency with matched TR expressions. Besides, our method enables identifying TR target genes as well as building GRNs at the single-cell resolution based on a regulatory potential model. We demonstrate SCRIPs utility in accurate cell-type clustering, lineage tracing, and inferring cell-type-specific GRNs in multiple biological systems. SCRIP is freely available at https://github.com/wanglabtongji/SCRIP.

bioinformatics↗

An integrated strain-level analytic pipeline utilizing longitudinal metagenomic data

The development of sequencing technology and analytic tools have advanced our insights into the complexity of microbiome. Since different strains within species may display great phenotypic variability, studying within-species variations enhances the understanding of microbial biological processes. However, most existing methods for strain-level analysis do not allow for the simultaneous interrogation of strain proportions and genome-wide variants in longitudinal metagenomic samples. In this study, we introduce LongStrain, an integrated pipeline for the analysis of metagenomic data from individuals with longitudinal or repeated samples. Our algorithm improves the efficiency and accuracy of strain identification by jointly modeling the strain proportion and genomic variants in combined multiple samples within individuals. With simulation studies of a microbial community and single species, we show that LongStrain is superior to three extensively used methods in variant calling and proportion estimation. Furthermore, we illustrate the potential applications of LongStrain in the real data analysis of The Environmental Determinants of Diabetes in the Young (TEDDY) study and a gastric intestinal metaplasia microbiome study. We investigate the association between the dynamic change of strain proportions and early life events, such as birth delivery mode, antibiotic treatment, and weaning. By joint analysis of phylogeny and strain transition, we also identify a subspecies clade of Bifidobacterium longum which is significantly correlated with breastfeeding.

bioinformatics↗

Comprehensive dissection of immune microenvironment in the progression of early gastric cancer at spatial and single-cell resolution

While the changes of tumor immune microenvironment (TME) have critical implications for most tumor progression, works that could reveal the compositions and immunity features of TME are needed. Profiling gastric malignant cells at single-cells resolution has shown the transcriptional heterogeneity is represented at different states of gastric cancer, implying that diverse cell states may exist, including immune cells, and all components in TME make some balances in early gastric cancer (EGC) progression. However, it remains unclear how immune cells contributing malignancy of gastritis, constituting general characteristics of gastric TME. Furthermore, the role of specific interactions among cells in gastric TME remains to be illustrated. Here, we performed spatial transcriptomes and single-cell RNA-seq analysis across 18 gastric samples, identifying 17 celltypes and reconstructing their location information. We found that immune cells represented different degree of dysregulations during the progression from non-atrophic gastritis (NAG), atrophic gastritis (AG) to EGC, including imbalance of cytotoxic and inhibitory effects in T cells, maturation inhibition in B cells and malignant genes up-regulated obviously in myeloid cells. Besides, pathway activities showed that hypoxia, reactive oxygen species and fatty metabolism signaling were activated from AG stage, which may accelerate progression of EGC. Moreover, cellular interactions further identified the roles of hypoxia in gastric TME. Overall, the multi-omics data presented in this study offer a comprehensive view of immune cell types, states changes and locations within the gastric tissues during the progression from NAG, AG to EGC, advancing our understanding of the composition and immunity of different gastric states, offering diagnostic and preventive thoughts for EGC.

cancer biology↗

An ACE2-blocking antibody confers broad neutralization and protection against Omicron and other SARS-CoV-2 variants

The ongoing evolution of SARS-CoV-2 has resulted in the emergence of Omicron, which displays striking immune escape potential. Many of its mutations localize to the spike protein ACE2 receptor-binding domain, annulling the neutralizing activity of most therapeutic monoclonal antibodies. Here we describe a receptor-blocking human monoclonal antibody, 87G7, that retains ultrapotent neutralization against SARS-CoV-2 variants including the Alpha, Beta, Gamma, Delta and Omicron (BA.1/BA.2) Variants-of-Concern (VOCs). Structural analysis reveals that 87G7 targets a patch of hydrophobic residues in the ACE2-binding site that are highly conserved in SARS-CoV-2 variants, explaining its broad neutralization capacity. 87G7 protects mice and/or hamsters against challenge with all current SARS-CoV-2 VOCs. Our findings may aid the development of sustainable antibody-based strategies against COVID-19 that are more resilient to SARS-CoV-2 antigenic diversity. One sentence summaryA human monoclonal antibody confers broad neutralization and protection against Omicron and other SARS-CoV-2 variants

microbiology↗

Spatially Resolved Transcriptomics for Evaluation of Intracranial Vessels in a Rabbit Model: Proof of Concept

BackgroundBetter understanding of vessel biology and vascular pathophysiology is needed to improve understanding of cerebrovascular disorders. Tissue from diseased vessels can offer the best data. Rabbit models can be effective for studying intracranial vessels, filling gaps resulting from difficulties acquiring human tissue. Spatially-resolved transcriptomics (SRT) in particular hold promise for studying such models as they build on RNA sequencing methods, augmenting such data with histopathology. MethodsRabbit brains with intact arteries were flash frozen, cryosectioned, and stained with H&E to confirm adequate inclusion of intracranial vessels before proceeding with tissue optimization and gene expression analysis using the Visium SRT platform. SRT results were analyzed with k-means clustering analysis, and differential gene expression was examined, comparing arteries to veins. ResultsCryosections were successfully mounted on Visium proprietary slides. Quality control thresholds were met. Optimum permeabilization was determined to be 24 minutes for the tissue optimization step. In analysis of SRT data, k-means clustering distinguished vascular tissue from parenchyma. When comparing gene expression traits, the most differentially expressed genes were those found in smooth muscle cells. These genes were more commonly expressed in arteries compared to veins. ConclusionsIntracranial vessels from model rabbits can be processed and analyzed with the Visium SRT platform. Face validity is found in the ability of SRT data to distinguish vessels from parenchymal tissue and differential expression analysis accurately distinguishing arteries from veins. SRT should be considered for future animal model investigations into cerebrovascular diseases.

cell biology↗

An automated pipeline for extracting quantitative histological metrics for voxelwise MRI-histology comparisons

The acquisition of MRI and histology in the same post-mortem tissue sample enables direct correlation between MRI and histologically-derived parameters. However, there still lacks a standardised automated pipeline to process histology data, with most studies relying on heavy manual intervention. Here, we introduce an automated pipeline to extract a quantitative histological measure for staining density (stain area fraction) from multiple immunohistochemical (IHC) stains. The pipeline is designed to directly address key IHC artefacts related to tissue staining and slide digitisation. Here, the pipeline was applied to post-mortem human brain data from multiple subjects, relating MRI parameters (FA, MD, R2*, R1) to IHC slides stained for myelin, neurofilaments, microglia and activated microglia. Utilising high-quality MRI-histology coregistrations, we then performed whole-slide voxelwise comparisons (simple correlations, partial correlations and multiple regression analyses) between multimodal MRI- and IHC-derived parameters. The pipeline was found to be reproducible, robust to artefacts and generalisable across multiple IHC stains. Our partial correlation results suggest that some simple MRI-SAF correlations should be interpreted with caution, due to the co-localisation of certain tissue features (e.g. myelin and neurofilaments). Further, we find activated microglia to consistently be the strongest predictor of DTI FA, which may suggest sensitivity of diffusion MRI to neuroinflammation. Taken together, these results show the utility of this approach in carefully curating IHC data and performing multimodal analyses to better understand microstructural relationships with MRI.

neuroscience↗

Heterotrimeric G protein α subunit (GPA1) regulates the response to low-nitrogen stress in Arabidopsis by interacting with AtNRT1.4 and AtATG8a

Efficient nitrogen absorption and utilization are important factors for higher plants to increase yield and reduce eutrophication (caused by excessive use of nitrogen fertilizers). Heterotrimeric G proteins, including three subunits of , {beta}, and {gamma}, participate in the pathway regulating nitrogen absorption and utilization in plants. However, the regulatory mechanism remains largely obscured. In this study, our results revealed that the G protein subunit (AtGPA1) mutant gpa1-4 was tolerant to low-nitrogen stress in Arabidopsis. AtGPA1 was shown to directly interact with a nitrate transporter (AtNRT1.4) and a key autophagy-related protein (AtATG8a) on the plasma membrane using the yeast hybrid system and pull-down assay (in vitro) and BiFC assay (in vivo). GUS staining and subcellular localization showed that AtGPA1 and AtNRT1.4 were co-expressed in roots and leaf veins and on the plasma membrane. Under low-nitrate conditions, the single mutant gpa1-4 and NRT1.4RNAi plants (AtNRT1.4RNA interference plants) and the double mutant NRT1.4RNAi/gpa1-4 plants (AtNRT1.4RNA interference plants on a gpa1-4 background) were healthier than the wild type plants. Moreover, the phenotype of the double mutant NRT1.4RNAi/gpa1-4 plants was closer to that of the NRT1.4RNAi plants compared to that of the gpa1-4 mutants. The results of the nitrate efflux rate assay in roots were consistent with the phenotypic changes under low-nitrogen conditions. These results indicated that AtGPA1 is an upstream factor that regulated the response to low-nitrogen stress through interaction with AtNRT1.4. In addition, we found that transgenic plants overexpressing AtATG8a were more tolerant to low-nitrogen stress, and their phenotype was similar to that of gpa1-4 mutants and double mutant ATG8aOX/gpa1-4 plants (AtATG8a overexpressing plants on a gpa1-4 mutant background). Further, autophagosome observations were consistent with the phenotypes in mutant plants, indicating that AtGPA1 regulated the response to low-nitrogen stress in Arabidopsis plants by affecting the autophagosome assembly. Our findings may provide a new model for improving nitrogen-use efficiency through genetical modification to boost crop yields. One sentence summaryAtGPA1 negative regulates low nitrogen stress response by interaction with a nitrate transporter, AtNRT1.4 and an autophagy-related protein, AtATG8a in Arabidopsis.

physiology↗

Harringtonine has the effects of double blocking SARS-CoV-2 membrane fusion

Fusion with host cell membrane is the main mechanism of infection of SARS-CoV-2. Here, we propose a new strategy to double block SARS-CoV-2 membrane fusion by using Harringtonine (HT), a small-molecule antagonist. By using cell membrane chromatography (CMC), we found that HT specifically targeted the SARS-CoV-2 S protein and host cell TMPRSS2, and then confirmed that HT can inhibit pseudotyped virus membrane fusion. Furthermore, HT successfully blocked SARS-CoV-2 infection, especially in the delta and Omicron mutant. Since HT is a small-molecule antagonist, it is minimally affected by the continuous variation of SARS-CoV-2. Our findings show that HT is a potential small-molecule antagonist with a new mechanism of action against SARS-CoV-2 infection, and thus HT mainly targets the S protein, and thus, greatly reduces the damage of the S proteins autotoxicity to the organ system, has promising advantages in the clinical treatment of COVID-19.

pharmacology and toxicology↗

Close relatives of MERS-CoV in bats use ACE2 as their functional receptors

Middle East Respiratory Syndrome coronavirus (MERS-CoV) and several bat coronaviruses employ Dipeptidyl peptidase-4 (DPP4) as their functional receptors1-4. However, the receptor for NeoCoV, the closest MERS-CoV relative yet discovered in bats, remains enigmatic5. In this study, we unexpectedly found that NeoCoV and its close relative, PDF-2180-CoV, can efficiently use some types of bat Angiotensin-converting enzyme 2 (ACE2) and, less favorably, human ACE2 for entry. The two viruses use their spikes S1 subunit carboxyl-terminal domains (S1-CTD) for high-affinity and species-specific ACE2 binding. Cryo-electron microscopy analysis revealed a novel coronavirus-ACE2 binding interface and a protein-glycan interaction, distinct from other known ACE2-using viruses. We identified a molecular determinant close to the viral binding interface that restricts human ACE2 from supporting NeoCoV infection, especially around residue Asp338. Conversely, NeoCoV efficiently infects human ACE2 expressing cells after a T510F mutation on the receptor-binding motif (RBM). Notably, the infection could not be cross-neutralized by antibodies targeting SARS-CoV-2 or MERS-CoV. Our study demonstrates the first case of ACE2 usage in MERS-related viruses, shedding light on a potential bio-safety threat of the human emergence of an ACE2 using "MERS-CoV-2" with both high fatality and transmission rate.

microbiology↗

Reduced inflammatory response and promoted multiciliated cell differentiation in mice protected by defective interfering influenza virus

Influenza defective interfering (DI) viruses have long been considered promising antiviral candidates because of their ability to interfere with replication-competent viruses and to induce antiviral immunity. However, the mechanisms underlying DI-mediated antiviral immunity have not been extensively explored. Here, we demonstrated interferon (IFN) independent protection conferred by influenza DI virus against homologous virus infection in mice deficient in type I and III IFN signaling. By integrating transcriptional and post-transcriptional regulatory data we identified unique host signatures in response to DI co-infection. DI-treated mice exhibited reduced viral transcription, less intense inflammatory and innate immune responses, and primed multiciliated cell differentiation in their lungs at an early stage of infection, even in the absence of type I or III IFNs. Overall, our study provides mechanistic insight into the protection mediated by DIs, implying a unifying theme involving inflammation and multiciliogenesis in maintaining respiratory homeostasis, and reveals their IFN-independent antiviral activity.

microbiology↗

SARS-CoV-2 Viral Genes Compromise Survival and Functions of Human Pluripotent Stem Cell-derived Cardiomyocytes via Reducing Cellular ATP Level

Cardiac manifestations are commonly observed in COVID-19 patients and prominently contributed to overall mortality. Human myocardium could be infected by SARS-CoV-2, and human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) are susceptible to SARS-CoV-2 infection. However, molecular mechanisms of SARS-CoV-2 gene-induced injury and dysfunction of human CMs remain elusive. Here, we find overexpression of three SARS-CoV-2 coding genes, Nsp6, Nsp8 and M, could globally compromise transcriptome of hPSC-CMs. Integrated transcriptomic analyses of hPSC-CMs infected by SARS-CoV-2 with hPSC-CMs of Nsp6, Nsp8 or M overexpression identified concordantly activated genes enriched into apoptosis and immune/inflammation responses, whereas reduced genes related to heart contraction and functions. Further, Nsp6, Nsp8 or M overexpression induce prominent apoptosis and electrical dysfunctions of hPSC-CMs. Global interactome analysis find Nsp6, Nsp8 and M all interact with ATPase subunits, leading to significantly reduced cellular ATP level of hPSC-CMs. Finally, we find two FDA-approved drugs, ivermectin and meclizine, could enhance the ATP level, and ameliorate cell death and dysfunctions of hPSC-CMs overexpressing Nsp6, Nsp8 or M. Overall, we uncover the global detrimental impacts of SARS-CoV-2 genes Nsp6, Nsp8 and M on the whole transcriptome and interactome of hPSC-CMs, define the crucial role of ATP level reduced by SARS-CoV-2 genes in CM death and functional abnormalities, and explore the potentially pharmaceutical approaches to ameliorate SARS-CoV-2 genes-induced CM injury and abnormalities.

molecular biology↗

Quantitative proteomics of the CDK9 interactome reveals a novel function of the HSP90-CDC37-P-TEFb complex for BETi-induced HIV-1 latency reactivation

Brd4 has been intensively investigated as a promising drug target because of its implicated functions in oncogenesis, inflammation and HIV-1 transcription. The formation of the Brd4-P-TEFb (CDK9/Cyclin T1) complex and its regulation of transcriptional elongation is critical for HIV latency reactivation and expression of many oncogenes. To further investigate the mechanism of the Brd4-P-TEFb complex in controlling elongation, mass spectrometry-based quantitative proteomics of the CDK9 interactome was performed. Upon treatment with the selective BET bromodomain inhibitor (BETi) JQ1, 535 proteins were successfully identified with high confidence as CDK9-interacting proteins. Among them, that increased bindings of HSP90 and CDC37 to CDK9 were particularly striking, and our data suggest that the HSP90-CDC37-P-TEFb complex is involved in controlling P-TEFbs dynamic equilibrium during BETi-induced HIV-1 latency reactivation. Furthermore, the HSP90-CDC37-P-TEFb complex directly regulates HIV-1 transcription and relies on the recruitment by heat shock factor 1 (HSF1) for binding to the HIV-1 promoter. These results advance the understanding of HSP90-CDC37-P-TEFb in HIV-1 latency reversal and enlighten the development of potential strategies to eradicate HIV-1 using a combination of targeted drugs.

molecular biology↗

Single cell profiling of γδ hepatosplenic T-cell lymphoma unravels tumor cell heterogeneity associated with disease progression

Hepatosplenic T-cell lymphoma (HSTCL), mostly derived from {gamma}{delta} T cells, is a rare but very aggressive lymphoma with poor outcomes. The molecular pathogenesis driving HSTCL is largely unknown while only limited treatment options are available. In this study, by performing paired single cell RNA-seq and T cell receptor (TCR) sequencing on biopsies from a HSTCL patient pre- and post-chemotherapy treatments, we characterized unique gene expressing signatures of malignant {gamma}{delta} T cells, with a set of marker genes were newly identified in HSTCL (AREG, PLEKHA5, VCAM1 etc.). Although the malignant {gamma}{delta} T cells were expanded from a single TCR clonotype according to their TCR identities, they evolved into two transcriptional distinct tumor subtypes during the disease progression. The Tumor_1 subtype was dominant in pre-treatment samples with highly aggressive phenotypes. While the Tumor_2 had relative mild cancer hallmark signatures but expressed genes associated with tumor survival signal and drug resistance (IL32, TOX2, AIF1, AKAP12 etc.), and finally became the main tumor subtype post-treatment. We further dissected the tumor microenvironment of the HSTCL and noticed that CD8 memory T cells were clonal expanded post-treatment. In addition, we discovered dynamically rewiring cell-cell interaction networks during the treatment. The tumor cells had reduced communications with the microenvironment post-treatment. Our study reveals heterogenous and dynamic tumor and microenvironment underlying pathogenesis of HSTCL and may contribute to identify novel targets for diagnosis and cure of HSTCL in the future.

cancer biology↗

SELINA: Single-cell Assignment using Multiple-Adversarial Domain Adaptation Network with Large-scale References

The rapid accumulation of single-cell RNA-seq data has provided rich resources to characterize various human cell types. Cell type annotation is the critical step in analyzing single-cell RNA-seq data. However, accurate cell type annotation based on public references is challenging due to the inconsistent annotations, batch effects, and poor characterization of rare cell types. Here, we introduce SELINA (single cELl identity NAvigator), an integrative annotation transferring framework for automatic cell type annotation. SELINA optimizes the annotation for minority cell types by synthetic minority over-sampling, removes batch effects among reference datasets using a multiple-adversarial domain adaptation network (MADA), and fits the query data with reference data using an autoencoder. Finally, SELINA affords a comprehensive and uniform reference atlas with 1.7 million cells covering 230 major human cell types. We demonstrated the robustness and superiority of SELINA in most human tissues compared to existing methods. SELINA provided a one-stop solution for human single-cell RNA-seq data annotation with the potential to extend for other species.

bioinformatics↗

FRET monitoring of transcription factor activities in living bacteria

Bacteria adapt to the constantly changing environments largely by transcriptional regulation through the activities of various transcription factors (TFs). However, techniques that monitor the in situ TF-promoter interactions in living bacteria are lacking. Herein, we developed a whole-cell TF-promoter binding assay based on the intermolecular Forster resonance energy transfer (FRET) between a fluorescent unnatural amino acid CouA which is genetically encoded into defined sites in TFs and the live cell fluorescent nucleic acid stain SYTO 9. We show that this new FRET pair monitors the intricate TF-promoter interactions elicited by various types of signal transduction systems with specificity and sensitivity. Furthermore, the assay is applicable to identify novel modulators of the regulatory systems of interest and monitor TF activities in bacteria colonized in C. elegans. In conclusion, we established a tractable and sensitive TF-promoter binding assay in living bacteria which not only complements currently available approaches for DNA-protein interactions but also provides novel opportunities for functional annotation of bacterial signal transduction systems and studies of the bacteria-host interface.

molecular biology↗

Cell- and non-cell-autonomous ARF3 coordinates meristem proliferation and organ patterning in Arabidopsis

In cell-cell communication, non-cell-autonomous transcription factors play vital roles in controlling plant stem cell fate. We previously reported that AUXIN RESPONSE FACTOR 3 (ARF3), a member of the ARF family with critical roles in floral meristem maintenance and determinacy, has a distinct accumulation pattern that differs from the expression domain of its encoding gene in the shoot apical meristem (SAM). However, the biological meaning of this difference is obscure. Here, we demonstrate that ARF3 expression is mainly activated at the periphery of the SAM by auxin, where ARF3 cell-autonomously regulates the expression of meristem-organ boundary-specific genes, such as CUP-SHAPED COTYLEDON1-3 (CUC1-3), BLADE ON PETIOLE1-2 (BOP1-2) and TARGETS UNDER ETTIN CONTROL3 (TEC3) to determine organ patterning. We also show that ARF3 is translocated into the organizing center, where it represses cytokinin activity and WUSCHEL expression to regulate meristem activity non-cell-autonomously. Therefore, ARF3 acts as a molecular link that mediates the interaction of auxin and cytokinin signaling in the SAM while coordinating the balance between meristem maintenance and organogenesis. Our findings reveal an ARF3-mediated coordination mechanism through cell-cell communication in dynamic SAM maintenance.

developmental biology↗