Biology subjects

Singh, Y.

Publications and source records attributed to Singh, Y..

At least 19 recordsLinked to original sources

bioRxiv2026

Scale-resolved correlation functions unify spatial omics across platforms and resolutions

Spatial omics platforms populate a multidimensional parameter space and differ in resolution, panel size, sensitivity, and modality. This diversity has led to platform-specific analyses whose results are rarely comparable. Here we present SCOTE (Spatial COvariance TEnsors), a computational framework that quantifies spatial relationships of all feature pairs across all length scales, for molecule coordinates and binned counts alike. Measuring the same quantity, with statistical errors, across platforms, samples, and patients, SCOTE separates measurement effects from biology, with platform artifacts appearing as identifiable, scale-localized features. SCOTE's molecule-level functions resolved a knockout effect in mouse spleen that cell-level analyses missed, and could show that tissue area and replicates, not molecule depth, set the statistical error. To match the growth of spatial omics data sets, SCOTE runs efficiently on CPUs and GPUs, and processes a billion-molecule whole-transcriptome section at all length scales, with uncertainties, in 26 minutes on a single GPU.

bioinformatics↗

bioRxiv2026

Ageing of the Upper Airway Epithelial Niche Limits Tissue-Resident T Cell Immunity

Respiratory tract infections are a major cause of morbidity and mortality among older adults worldwide. Yet, how ageing shapes protective immunity within the upper respiratory tract (URT) remains poorly understood. Here, we profiled the nasal immune landscape of young adults and older adults with and without frailty, using high-dimensional cytometry, proteomics, single-cell transcriptomics and T cell receptor (TCR) sequencing. Ageing was associated with a selective reduction of tissue-resident memory T (Trm) cells, independent of effector T cell numbers, inflammageing levels or frailty and was accompanied by a decline in T cell receptor repertoire stability. Trm cells from older adults also showed decreased steady-state IFN{gamma} expression, accompanied by reduced antiviral transcriptional programs in the mucosa. Mechanistically, in vitro PBMC-epithelium co-culture models revealed that older adults have a reduced capacity for Trm differentiation, which was associated with a diminished epithelial TGF-{beta} secretion, driven by reduced expression in ciliated epithelial cells. Together, these findings reveal that URT immunity deteriorates with age due to disrupted epithelial-immune crosstalk. This identifies the epithelial niche as a key regulator of mucosal immune ageing and suggests that enhancing TGF{beta} signaling may improve the effectiveness of mucosal airway vaccination strategies in older populations.

immunology↗

bioRxiv2026

The E. coli DEAD box ATPase CsdA, is a NAD+ capped RNA binding protein

5' nicotinamide adenine dinucleotide (NAD+) caps are one of the most common metabolites derived non-canonical caps reported on bacterial RNAs. Multiple decapping proteins are known to regulate the stability of NAD+ capped transcripts. However, no other proteins have been identified that preferentially interact with these NAD+ caps, and mechanistic details of the cap-dependent recognition remain poorly understood. Using an affinity capture approach, we identified multiple E. coli proteins that selectively recognize NAD+ caps, including the ATP-dependent RNA helicase, CsdA. CsdA preferentially interacts directly with NAD+ capped RNAs and can discriminate between 5' NAD+ capped and 5' triphosphate end transcripts. Binding to NAD+ capped RNA versus 5' triphosphate RNA more greatly enhances the ATPase activity of CsdA and the presence of NAD+ caps on transcripts modulates the ability of CsdA to form RNA condensates. Furthermore, we find that CsdA enhances the decapping activity of the NADH hydrolase NudC, suggesting CsdA plays a role in regulating the degradation of NAD+ capped transcripts. CsdA is the first identified NAD+ cap reader protein and its preference for binding NAD+ capped RNA provides a mechanism by which E. coli cells link RNA stability to the identity of the 5' cap. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/730015v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@115a057org.highwire.dtl.DTLVardef@d1c2c6org.highwire.dtl.DTLVardef@14a6d2dorg.highwire.dtl.DTLVardef@145ccff_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2026

A cell surface proteomic atlas reveals socioeconomic status associated immune diversity

Socioeconomic status (SES) is a potent determinant of immune variation, yet unbiased approaches to holistically map the effect of SES on the immune system are lacking. We developed a high-dimensional flow cytometry-based profiling approach to analyse 331 cell surface proteins across 33 immune cell subsets within an SES-stratified Senegalese cohort, alongside a European cohort (Netherlands). We identified 108 SES-related markers across the immune system, revealing that lower SES individuals exhibited downregulation of surface proteins, affecting in particular adhesins, chemokine and complement receptors. Conversely, lower SES was associated with hallmarks of chronic activation and exhaustion including upregulation of immune checkpoints. Metabolic profiling demonstrated that while lower SES individuals displayed elevated baseline RNA transcription, higher SES individuals exhibited superior protein translation rates. We validated these SES-related immune trends in an independent cohort and provide an interactive online resource for exploring this surface protein atlas on immune cell subsets. Taken together, these findings provide a global overview of how the cell surface proteome varies by SES, and identify molecular changes that can affect vaccine efficacy and disease outcomes.

immunology↗

bioRxiv2025

Urinary Exosomal miRNA Profiling Reveals Sensitive Non-Invasive Diagnosis of Bladder Cancer

UnstructuredmiRNAs represent a transformative advancement in both research and clinical management of urinary bladder cancer (UBC), emerging as clinically significant molecular targets with the potential to revolutionize existing diagnostic standards. This study exploited the robust stability of miRNAs and profiled urinary miRNAs in UBC patients and controls through miRNA sequencing, revealing an expanded and altered miRNA repertoire in cancer samples. Validation in an independent cohort revealed fold changes for miR-6724-5p, miR-1273h-5p, miR-7704, miR-200-5p, and miR-10400-5p ranged from [~]46 to [~]2,777 (p < 0.01). Stage-specific analyses highlighted dynamic miRNA expression linked to tumor progression. Diagnostic evaluation identified an optimal three-miRNA panel comprising miR-6724-5p, miR-10400-5p, and miR-7704, achieving diagnostic accuracies (AUC > 70%) and high sensitivity (>90%). These data demonstrate the potential of urinary mature miRNAs as robust biomarkers for non-invasive detection and monitoring of UBC in early stages, supporting their translation into clinical diagnostic assays pending larger prospective studies. StructuredO_ST_ABSBackgroundC_ST_ABSUrinary microRNAs (miRNAs) are promising candidates due to their molecular stability and disease-specific expression. miRNAs represent a transformative advancement in both research and clinical management of urinary bladder cancer (UBC), emerging as actionable molecular targets with the potential to revolutionize existing diagnostic standards. MethodsSmall RNA sequencing was performed on urine samples from UBC patients and healthy controls to profile miRNA expression. Mature miRNAs were prioritized by exclusion of precursor forms using computational filtering. Validation by quantitative RT-PCR was conducted on an independent, age-matched cohort (n = 45). Diagnostic potential of candidate miRNAs was assessed by receiver operating characteristic (ROC) curves and area under the curve (AUC) analyses. ResultsSequencing identified 865 known and 11 novel miRNAs, with UBC samples showing greater miRNA diversity (708 known miRNAs) compared to controls (540). Ten miRNAs were significantly dysregulated in UBC (p < 0.05). Validation revealed fold changes for miR-6724-5p, miR-1273h-5p, miR-7704, miR-200-5p, and miR-10400-5p ranged from [~]46 to [~]2,777 (p < 0.01). Stage-specific analyses highlighted dynamic miRNA expression linked to tumor progression. A three-miRNA panel (miR-6724-5p, miR-10400-5p, miR-7704) demonstrated superior diagnostic performance (AUC > 70%, sensitivity > 90%). ConclusionMature urinary miRNAs exhibit reproducible, stage-specific dysregulation in UBC and a combinatorial panel offers sensitive, specific non-invasive detection. These findings warrant further multicenter validation for clinical application.

cancer biology↗

bioRxiv2025

CardioWAS Pathway-Based RNA-Seq and Genome Integration Platform for CVD Omics-Wide Associations

The integration of transcriptomic and genomic data is essential for dissecting the molecular basis of complex cardiovascular diseases (CVD). Existing resources primarily focus on differential gene expression at the individual gene level, with limited support for pathway-level interpretation or genomic integration. We introduce CARDIOWAS (Cardiovascular Omics-Wide Association Analysis Platform), the first Shiny-based, cardiovascular-specific platform that performs pathway-centric expression profiling in conjunction with Genome-Wide Association Study (GWAS) integration. CARDIOWAS systematically aggregates and harmonizes RNA-seq data from 18 NCBI GEO studies, comprising 419 heart failure (HF) and 208 control samples, and applies robust batch correction followed by DESeq2-based differential expression analysis. Gene-level statistics are translated into pathway effect sizes using curated KEGG and Reactome annotations, enabling systematic evaluation of disease-relevant biological modules. CARDIOWAS extends beyond transcriptomic profiling by incorporating GWAS-identified loci, mapping variants to proximal genes and pathways, and leveraging machine learning models to highlight transcriptome-variant-pathway associations. Both germline and somatic variant contributions can be interrogated, providing a framework to link non-coding variation with altered pathway activity. Application of the platform identified 12 HF-specific and 19 CAD-enriched pathways, implicating inflammatory, metabolic, and signaling processes central to disease biology. Implemented as a user-friendly Shiny interface, CARDIOWAS allows researchers to upload transcriptomic data, visualize perturbed pathways, evaluate variant burden, and prioritize druggable targets. By uniting large-scale RNA-seq data with GWAS evidence in a pathway-centric framework, CARDIOWAS represents a novel, reproducible, and accessible tool for precision medicine in CVD and offers a resource for omics-driven hypothesis generation and translational research.

bioinformatics↗

bioRxiv2025

Non-Invasive Diagnostic Evaluation of Urinary Exosomal Let-7c Cluster Expression in Bladder Cancer Using Machine Learning Approaches

BackgroundBladder cancer (BCa) diagnosis typically relies on invasive cystoscopy, which is effective but costly and uncomfortable. Urinary microRNAs (miRNAs), especially exosomal ones, are promising non-invasive biomarkers due to their stability in biological fluids and disease specificity. However, challenges such as population variability, methodological inconsistencies and normalization issues hinder their clinical translation, emphasizing the need for innovative approaches to enhance diagnostic performance. ObjectiveTo evaluate the diagnostic potential of urinary exosomal let-7c cluster (let-7c-5p, miR-99a-5p and miR-125b-5p) in BCa patients by integrating miRNA expression data with Machine Learning (ML) models. MethodsUrine samples were collected from 66 participants, including 50 BCa patients and 16 healthy controls (HC). Exosomal miRNAs were isolated and quantified using Quantitative Real-Time-Polymerase-Chain-Reaction (qRT-PCR). Statistical analysis and hypothesis tests were conducted to explore the nature and diagnostic relevance of individual biomarkers. A logistic regression classifier was applied to evaluate both the combined and differential diagnostic capabilities of the selected biomarkers. Accuracy, precision, recall and AU-ROC scores were used to assess model performance. Bioinformatics analysis was performed to identify pathways associated with the features prioritized by the ML models, ensuring their relevance to BCa. ResultsThe result revealed significant differentiation between BCa patients and HC, with miR-99a-5p (p=0.013, AU-ROC=0.71) and miR-125b-5p (p=0.047, AU-ROC=0.64) demonstrating reliable diagnostic performance (let-7c-5p showed weaker discrimination, AU-ROC=0.65, p>0.1). The logistic regression ML model achieved an accuracy of 80.0% (AU-ROC=0.86, recall=100%) in distinguishing cancer from HC and 53.3% (AU-ROC=0.63) when applied to miRNA-only grade classification. When clinical variables were integrated with miRNA expression, performance improved to 73.3% accuracy (AU-ROC=0.61) for high-versus low-grade differentiation. Across Ta-T2, miR-99a-5p displayed relatively better separation, whereas let-7c-5p and miR-125b-5p showed weak stage-related differences. The integration of bioinformatics analysis confirmed the biological relevance of these miRNAs in BCa-related pathways, including PI3K-Akt, p53, NF-{kappa}B and RAS/MAPK signaling, with hub genes such as TP53, MYC, EGFR, and CCND1 identified, further validating the diagnostic utility of the selected biomarkers. ConclusionUrinary let-7c cluster miRNAs demonstrate promising diagnostic potential when analyzed with ML models, offering a non-invasive alternative to conventional methods. These findings highlight the promise of ML-based approaches alongside molecular markers for advancing clinical diagnostics in BCa.

molecular biology↗

bioRxiv2025

The Ca2+ Channel CYCLIC NUCLEOTIDE GATED CHANNEL13 (CNGC13) regulates systemic wound signalling and immunity against Spodoptera herbivory

Insect herbivory elicits rapid and complex signalling responses in plants, including membrane depolarization, cytosolic Ca2+ elevation and activation of jasmonate-mediated defense pathways in local and systemic leaves. These early events are orchestrated by calcium-permeable channels and regulatory components that generate stimulus-specific cytosolic Ca2+ signatures. However, the molecular mechanisms that generate long-distance Ca2+ propagation and systemic immune activation on herbivory remain poorly defined. Here, we identify CYCLIC NUCLEOTIDE GATED CHANNEL13 (CNGC13) as a novel plasma membrane-localized, phloem-expressed Ca2+ channel that is essential for systemic wound signalling and defense against lepidopteran pest, Spodoptera litura in Arabidopsis thaliana. CNGC13 is rapidly induced by wounding and herbivory, mediates cytosolic Ca2+ influx, and is required for efficient propagation of Ca2+ signals from wounded to distal leaves. Loss of CNGC13 compromises the thioglucosidase-dependent breakdown of aliphatic glucosinolates into aglucones/isothiocyanates within the vascular tissue, which are essential for wounding-induced systemic Ca2+ wave propagation. Consequently, cngc13 mutants display impaired systemic jasmonate accumulation in distal leaves, reduced glucosinolate levels and enhanced herbivore susceptibility. CNGC13 is also required for AtPep-induced Ca2+ elevation and Reactive Oxygen Species (ROS) signalling and interacts with the receptor kinase, PEPR2, implicating it in DAMP-mediated immune responses. Although CNGC13 and CNGC19 function cooperatively in herbivore defense, they do not physically interact, suggesting independent but converging roles. Our study identifies CNGC13 as a vasculature-localized Ca2+-permeable channel that functions downstream of PEPR2 receptor, to sustain systemic signalling, operating in a distinct yet converging pathway alongside known glutamate receptor-like channels during long-distance wound responses. SignificancePlants must detect and respond to insect herbivory rapidly by activating systemic immunity to trigger defense responses. Calcium (Ca2+) signalling plays a central role in this defense network, yet the identities and specific functions of Ca2+ channels involved in long-distance herbivory signalling remain poorly understood. Here, we identify the plasma membrane-localized channel CYCLIC NUCLEOTIDE GATED CHANNEL13 (CNGC13) as a key integrator of mechanical damage perception, ricca factor-mediated systemic signalling, and jasmonate-dependent defense against Spodoptera herbivory in Arabidopsis. CNGC13 facilitates systemic Ca2+ wave propagation, activates jasmonate and glucosinolate biosynthesis, and promotes the perception of damage-associated molecular pattern (DAMP) molecules to confer herbivore resistance. This work uncovers a previously uncharacterized calcium channel that plays a crucial dual role in systemic wound signalling.

plant biology↗

bioRxiv2025

A novel AAA+ ATPase required for sporulation and stress response in Bacillus anthracis

AAA+ proteins function as molecular machines that utilize ATP to perform diverse cellular functions, including protein homeostasis, stress regulation, and cell cycle/developmental processes. In this study, we identified a novel AAA+ ATPase BAS PrkA in B. anthracis Sterne 34F2 which has 88 % protein homology to Bacillus subtilis PrkA. Conserved domain analysis confirms BAS PrkA has an N-terminal AAA+ ATPase domain with characteristic Walker A and Walker B motifs and a conserved secondary region of homology (SRH) domain, along with a C-terminal cAMP-dependent protein kinase domain. Based on Alpha Fold3 predicted structure, we classified BAS PrkA as part of Clade III of the AAA+ superfamily. Contrary to the reported enzymatic activity in B. subtilis PrkA, we observed that BAS PrkA has negligible protease and kinase activity under in-vitro conditions. Nonetheless, BAS PrkA plays a significant role in regulating sporulation. It is temporally expressed during Stages II to VI during sporulation. A null mutant of BAS PrkA exhibits severe sporulation defects, with reduced spore viability, and down regulation of genes related to spore-coat formation. These phenotypes were restored in a complementation strain expressing BAS PrkA ectopically. Additionally, the null mutant strain showed compromised growth under ionic-osmotic stress conditions. Analysis of the BAS PrkA interactome revealed enrichment of two proteins, ProA and EzrA, that are implicated in osmotic stress response and the sporulation process, respectively. These findings show that BAS PrkA plays a critical role in sporulation and osmotic stress response in B. anthracis.

microbiology↗

bioRxiv2024

A clinical mutation in uvrA, a DNA repair gene, confers survival advantage to Mycobacterium tuberculosis in the host

DNA repair pathways play an essential role in maintaining the genomic integrity of bacteria, and a perturbation in their biological activity helps bacteria survive under duress. In drug-resistant clinical strains, we identified a Q135K mutation in the uvrA gene, a DNA repair pathway gene. To delineate the role of uvrA and the Q135K mutation, we generated the gene replacement mutant of UvrA (Rv{Delta}uvrA) in Mycobacterium tuberculosis H37Rv (Mtb-Rv). While the lack of UvrA function in Rv{Delta}uvrA could be restored upon complementation with uvrA, the uvrA-Q135K mutant identified in clinical drug-resistant strains failed to do so. This was reflected in higher mutation rates in Rv{Delta}uvrA and Rv{Delta}uvrA::uvrAQ135A, compared with wild-type Rv or Rv{Delta}uvrA::uvrA complemented strains in the presence and absence of oxidative stress. Killing kinetics experiments with anti-TB drugs showed increased survival of Rv{Delta}uvrA and Rv{Delta}uvrA::uvrAQ135K, strains compared with Rv or Rv{Delta}uvrA::uvrA. Importantly, Rv{Delta}uvrA and Rv{Delta}uvrA::uvrAQ135K showed enhanced survival in peritoneal macrophages and murine infection model of infection. Together, data suggests that acquiring Q135K mutation benefits the pathogen, which helps enhance the hosts survival adaptability. Author SummaryDNA repair mechanisms in an organism are necessary for correcting the errors generated during replication or when it is damaged/modified due to insults. As a GC organism, Mtb is highly prone to host-mediated attacks on its genome, which, if uncorrected, can impact its genome integrity. The drug-resistant clinical strains of Mtb harbor Q135K mutation in uvrA, the first enzyme in the nucleotide excision repair pathway. With the help of genetic, molecular, and murine challenge experiments, we show that the UvrA-Q135K mutation abrogates the enzymes activity, compromising the Mtb strain harboring the mutation in the oxidative and nitrosative stress. On the contrary, the mutation in UvrA imparts survival advantage in activated macrophages and murine infection models. Results presented argue that identified mutation helps in better adaptability in the host, which may include faster acquisition of drug resistance.

microbiology↗

bioRxiv2023

Bimodular Architecture of Bacterial Effector SAP05 Drives Ubiquitin-Independent Targeted Protein Degradation

In eukaryotes, targeted protein degradation (TPD) typically depends on a series of interactions among ubiquitin ligases that transfer ubiquitin molecules to substrates leading to degradation by the 26S proteasome. We previously discovered that the bacterial effector protein SAP05 mediates ubiquitin-independent TPD. SAP05 forms a ternary complex via interactions with the von Willebrand Factor Type A (vWA) domain of the proteasomal ubiquitin receptor Rpn10 and the Zinc-finger (ZnF) domains of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) and GATA BINDING FACTOR (GATA) transcription factors (TFs). This leads to direct TPD of the TFs by the 26S proteasome. Here, we report the crystal structures of the SAP05-vWA complex at 2.17 [A] resolution and of the SAP05-ZnF(SPL5) complex at 2.20 [A] resolution. Structural analyses revealed that SAP05 displays a unique bimodular architecture with two distinct non-overlapping surfaces, a loop surface with three protruding loops that form electrostatic interactions with ZnF, and a sheet surface featuring two {beta}-sheets, loops and -helices that establish polar interactions with vWA. SAP05 binding to ZnF TFs involves single amino acids responsible for multiple contacts, while SAP05 binding to vWA is more stable due to the necessity of multiple mutations to break the interaction. In addition, positioning of the SAP05 complex on the 26S proteasome points to a mechanism of protein degradation. Collectively, our findings demonstrate how a small bacterial bimodular protein can bypass the canonical UPS cellular proteolysis pathway, enabling ubiquitin-independent TPD in eukaryotic cells. This knowledge holds significant potential for the creation of novel TPD technologies.

biochemistry↗

bioRxiv2023

Maintained imbalance of triglycerides, apolipoproteins, energy metabolites and cytokines in long-term COVID-19 syndrome (LTCS) patients

Deep metabolomic, proteomic and immunologic phenotyping of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients have matched a wide diversity of clinical symptoms with potential biomarkers for coronavirus disease 2019 (COVID-19). Within here, several studies described the role of metabolites, lipoproteins and inflammation markers during infection and in recovered patients. In fact, after SARS-CoV-2 viral infection almost 20-30% of patients experience persistent symptoms even after 12 weeks of recovery which has been defined as long-term COVID-19 syndrome (LTCS). Emerging evidence revealed that a dysregulated immune system and persisting inflammation could be one of the key drivers of LTCS. However, how these small biomolecules such as metabolites, lipoprotein, cytokines and chemokines altogether govern pathophysiology is largely underexplored. Thus, a clear understanding how these parameters into an integrated fashion could predict the disease course may help to stratify LTCS patients from acute COVID-19 or recovered specimen and would help to elucidate a potential mechanistic role of these biomolecules during the disease course. Here, we report an integrated analysis of blood serum and plasma by in vitro diagnostics research NMR spectroscopy and flow cytometry-based cytokine quantification in a total of 125 individuals (healthy controls (HC; n=73), recovered (n=12), acute (n=7) and LTCS (n=33)). We identified that in LTCS patients lactate and pyruvate were significantly different from either healthy controls or acute COVID-19 patients. Further correlational analysis of cytokines and metabolites indicated that creatine, glutamine, and high-density lipoprotein (HDL) phospholipids were distributed differentially amongst patients or individuals. Of note, triglycerides and several lipoproteins (apolipoproteins Apo-A1 and A2) in LTCS patients demonstrate COVID-19-like alterations compared to HC. Interestingly, LTCS and acute COVID-19 samples were distinguished mostly by their creatinine, phenylalanine, succinate, 3-hydroxybutyrate (3-HB) and glucose concentrations, illustrating an imbalanced energy metabolism. Most of the cytokines and chemokines were present at low levels in LTCS patients compared with HC except IL-18 chemokine, which tended to be higher in LTCS patients and correlated positively with several amino acids (creatine, histidine, leucine, and valine), metabolites (lactate and 3-HB) and lipoproteins. The identification of these persisting plasma metabolites, lipoprotein and inflammation alterations will help to better stratify LTCS patients from other diseases and could help to predict ongoing severity of LTCS patients. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=127 SRC="FIGDIR/small/523998v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@ecdeacorg.highwire.dtl.DTLVardef@10f0f80org.highwire.dtl.DTLVardef@1c2ddaborg.highwire.dtl.DTLVardef@672120_HPS_FORMAT_FIGEXP M_FIG C_FIG Layman summary & significance of the researchAlmost 20-30% of individuals infected with the SARS-CoV-2 virus regardless of hospitalization status experience long-term COVID-19 syndrome (LTCS). It is devasting for millions of individuals worldwide and hardly anything is known about why some people experience these symptoms even after 3 to 12 months after the acute phase. In this, we attempted to understand whether dysregulated metabolism and inflammation could be contributing factors to the ongoing symptoms in LTCS patients. Total blood triglycerides and the Cory cycle metabolites (lactate and pyruvate) were significantly higher, lipoproteins (Apo-A1 and A2) were drastically lower in LTCS patients compared to healthy controls. Correlation analysis revealed that either age or gender are positively correlated with several metabolites (citrate, glutamate, 3-hydroxybutyrate, glucose) and lipoproteins (Apo-A1, HDL Apo-A1, LDL triglycerides) in LTCS patients. Several cytokines and chemokines were also positively correlated with metabolites and lipoproteins thus, dysregulation in metabolism and inflammation could be a potential contributory factor for LTCS symptoms.

immunology↗

bioRxiv2022

Comparative multi-OMICS single-cell atlas of five COVID-19 (rAdVV and mRNA) vaccines describe unique and distinct mechanisms of action

COVID-19 vaccines based on a range of expression platforms have shown considerable protective efficacy, generating antibody and T cell immune responses. However, molecular pathways underpinning COVID-19 vaccine priming of immunity against the SARS-CoV-2 virus have not yet been explored extensively. This analysis is critical to optimization of future vaccination strategies, schedules, and combinations. Thus, we investigated a cohort of individuals pre- and post-vaccination to understand the humoral and cellular immune response against different COVID-19 vaccines, including recombinant adenoviral vector (rAdVV) and mRNA-based vaccines. Single-cell RNA sequencing allowed characterization of monocytes, T, NK and B cell activation at the transcriptomics/proteomic level, in response to different COVID-19 vaccines. Our data revealed that different COVID-19 vaccines elicit a unique and distinct mechanism of action. Specifically, we revealed that rAdVV vaccines negatively regulate CD4+ T cell activation, leukocytes chemotaxis, IL-18 signalling and antigen presentation by monocytes whilst mRNA vaccines positively regulate NKT cell activation, platelets activation and chemokine signalling pathways. An antigen-specific T cell response was already observed following the 1st vaccine dose and was not further augmented after the subsequent 2nd dose of the same vaccine and it was dependent on the type of vaccination used. Our integrated three layered-analyses highlights that COVID-19 vaccines evoke a strong but divergent immune response at the RNA, protein, and cellular levels. Our approach is able to pinpoint efficacy and mechanisms controlling immunity to vaccination and open the door for better vaccination which could induce innate and adaptive immunity equally in the long term. Key findingsO_LIDecrease in major three cell types classical and non-classical monocytes and NK type III cells after COVID-19 vaccination C_LIO_LIIndividual vaccination (AZ, JJ, MD, PB) has differential effect on various immune cell subsets and regulates unique cell populations, whilst no change was observed for CV vaccination C_LIO_LIrAdVV and mRNA vaccines have different mechanism of action for activation of lymphocytes and monocytes, respectively C_LIO_LIrAdVV vaccines negatively regulates CD4+ T cell activation, leukocytes chemotaxis, IL-18 signalling and antigen presentation whilst mRNA vaccines positively regulate NKT cell activation, platelets activation and chemokine signalling pathways. C_LIO_LIAn antigen-specific T cell response was prompted after the 1st vaccine dose and not augmented after the subsequent 2nd dose of the same vaccine. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=107 SRC="FIGDIR/small/507666v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@11fd7eborg.highwire.dtl.DTLVardef@198a9c7org.highwire.dtl.DTLVardef@1b28735org.highwire.dtl.DTLVardef@1cadbb5_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2022

Immune dynamics at single cell protein level after delta/omicron infection in COVID-19 vaccinated convalescent individuals

Both COVID-19 mRNA or recombinant Adenovirus vector (rAdVV) based vaccines have shown a great efficacy in generating humoral and cellular immune responses. Two doses of the COVID-19 vaccines generate enough antibodies and generate spike-specific T cell responses. However, after 6-8 months there is a decline in antibody production and T cell responses. Due to the rise of new SARS-CoV-2 variants of concern, a third or even fourth dose of vaccine was recommended for the elderly, immune comprised and frontline medical health care workers. However, despite additional booster doses given, those who were infected with either delta or omicron (during December 2021 - March 2022) had symptoms of illness. By what means these COVID-19 vaccines provide immunity against the SARS-CoV-2 virus at the molecular level is not explored extensively yet and, it is an emerging research field as to how the SARS-CoV-2 virus is able to evade the host immunity. Most of the infected people had mild symptoms whilst some were asymptomatic. Many of the people had developed nucleocapsid antibodies against the SARS-CoV-2 delta/omicron variants confirming a humoral immune response against viral infection. Furthermore, cellular analysis shows that post-vaccinated recovered COVID-19 individuals have significantly reduced NK cells and increased T naive CD4+, TEM CD8+ and B cells. This decrease in cellular immunity corresponds to individuals who recovered from alpha variants infection and had mild symptoms. Our results highlight that booster doses clearly reduce the severity of infection against delta/omicron infection. Furthermore, our cellular and humoral immune system is trained by vaccines and ready to deal with breakthrough infections in the future.

immunology↗

bioRxiv2022

Single-cell RNA sequencing highlights a reduced function of natural killer and cytotoxic T cells in recovered COVID-19 pregnant women

Pregnancy is a complex phenomenon during which women undergo immense immunological change throughout this period. Having an infection with the SARS-CoV-2 virus leads to an additional burden on the highly stretched immune response. Some studies suggest that age-matched pregnant women are more prone to SARS-CoV-2 infection compared with normal healthy (non-pregnant) women, while alternative evidence proposed that pregnant women are neither susceptible nor develop severe symptoms. This discrepancy in different findings regarding the immune responses of pregnant women infected with SARS-CoV-2 virus is not well understood. In this study, we investigated how SARS-CoV-2 viral infection could modulate the immune landscape during the active infection phase and recovery in pregnant females. Using flow cytometry, we identified that intermediate effector CD8+ T cells were increased in pregnant women who had recovered from COVID-19 as opposed to those currently infected. Similarly, an increase in CD4+ T helper cells (early or late) during the recovered phase was observed during the recovery phase compared with infected pregnant women or healthy pregnant women, whilst infected pregnant women had a reduced number of late effector CD4+ T cells. CD3+CD4- CD8-NKT cells that diminished during active infection in contrast to healthy pregnant women were significant increase in recovered COVID-19 recovered pregnant women. Further, our single-cell RNA sequencing data revealed that infection of SARS-CoV-2 had changed the gene expression profile of monocytes, CD4+ effector cells and antibody producing B cells in convalescent as opposed to healthy pregnant women. Additionally, several genes with cytotoxic function, interferon signalling type I & II, and pro- and anti-inflammatory functions in natural killer cells and CD8+ cytotoxic T cells were compromised in recovered patients compared with healthy pregnant women. Overall, our study highlights that SARS-CoV-2 infection deranged the adaptive immune response in pregnant women and could be implicated in pregnancy complications in ongoing pregnancies.

immunology↗

bioRxiv2022

Transcriptome analysis reveals robust transcriptional reprogramming during early stages of Cicer-Ascochyta interaction

Ascochyta blight (AB) caused by a filamentous fungus Ascochyta rabiei is a major threat to global chickpea production. The mechanisms underlying chickpea response to A. rabiei remain elusive. Here, we investigated the comparative transcriptional dynamics of AB-resistant and susceptible chickpea genotypes upon A. rabiei infection to understand the early host defence response. Our findings revealed that AB-resistant plants underwent rapid and extensive transcriptional reprogramming compared to susceptible host. At early stage (24-hpi), mainly cell wall remodeling and secondary metabolite pathways were highly activated, while DEGs related with signaling components viz. protein kinases, transcription factors, and hormonal pathways show remarkable upsurge at 72-hpi, especially in resistant genotype. Notably, our data suggests imperative role of JA, ET, and ABA signaling in providing immunity against A. rabiei. Furthermore, gene co-expression networks and modules corroborated the importance of cell wall remodeling, signal transduction and phytohormone pathways. The hub genes such as MYB14, PRE6 and MADS-SOC1 discovered in these modules might be the master regulators governing chickpea immunity. Overall, we not only provide novel insights for comprehensive understanding of immune signaling components mediating AB resistance/susceptibility at early Cicer-Ascochyta interactions, but also offer a valuable resource for developing AB-resistant chickpea. HighlightsComparative transcriptomic and co-expression analysis of AB-resistant and susceptible chickpea genotypes reveals high-amplitude transcriptional dynamics in resistant plants, and also identifies TFs, PKs and phytohormone-crosstalk as core regulators for AB-resistance.

plant biology↗

bioRxiv2022

GWAS and functional studies implicate a role for altered DNA repair in the evolution of drug resistance in Mycobacterium tuberculosis

The emergence of drug resistance in Mycobacterium tuberculosis (Mtb) is alarming and demands in-depth knowledge for timely diagnosis. We performed genome-wide association analysis (GWAS) using 2237 clinical strains of Mtb to identify novel genetic factors that evoke drug resistance. In addition to the known direct targets, for the first time, we identified a strong association between the mutations in the DNA repair genes and the multidrug-resistant phenotype. To evaluate the impact of variants identified in the clinical samples in the evolution of drug resistance, we utilized knockouts and complemented strains in Mycobacterium smegmatis (Msm) and Mtb. Results show that variant mutations abrogated the function of MutY and UvrB. MutY variant showed enhanced survival compared with wild-type (Rv) when the Mtb strains were subjected to multiple rounds of ex vivo antibiotic stress. Notably, in an in vivo Guinea pig infection model, the MutY variant outcompeted the wild-type strain. Collectively, we show that novel variant mutations in the DNA repair genes abrogate their function and contribute to better survival under antibiotic/host stress conditions.

microbiology↗

bioRxiv2021

Marker-free imaging of α-Synuclein aggregates in a rat model of Parkinson' disease using Raman microspectroscopy

A hallmark of Parkinsons disease (PD) is the formation of Lewy bodies in the brain. Lewy bodies are rich in the aggregated form of misfolded -Synuclein (-Syn). The brain from PD patients can only be analysed after post-mortem, limiting the diagnosis of PD to the manifestation of motor symptoms. In PD patients and animal models phosphorylated -Syn was detected in the gut, thus, raising the hypothesizes that early-stage PD could be diagnosed based on colon tissues biopsies. Non-invasive marker-free technologies represent an ideal method to potentially detect aggregated -Syn in vivo. Raman microspectroscopy has been established for the detection of molecular changes such as alterations of protein structures. Here, the olfactory bulb in the brain and the muscularis mucosae of colon tissue sections of a human BAC-SNCA transgenic (TG) rat model was analysed using Raman imaging and microspectroscopy. Raman images from TG and WT rats were investigated using spectral, principal component and true component analysis. Spectral components indicated protein aggregates (spheroidal oligomers) in TG rat brain and colon tissues even at a young age but not in WT. In summary, we have demonstrated that Raman imaging is capable to detect -Syn aggregates in colon tissues of a PD rat model and making it a promising tool for future use in PD pathology.

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