Biology subjects

Joseph, J.

Publications and source records attributed to Joseph, J..

At least 19 recordsLinked to original sources

bioRxiv2026

The scaffold nucleoporin Nup188 undergoes liquid-liquid phase separation

Components of nuclear pore complexes are broadly classified into two categories: intrinsically disordered FG-repeat nucleoporins such as Nup98, which can undergo liquid-liquid phase separation, and scaffold nucleoporins, which form the NPC's structural framework. The basis for crosstalk of these nucleoporins within NPC and beyond is poorly understood. Here we show that human Nup188, a helical inner-ring scaffold protein, forms condensates both in purified form as well as at endogenous level. This condensate exhibits fusion, dissolved in 1,6-hexanediol and recovered after photobleaching, with dynamics and material properties comparable to those of hNup98 condensates. Moreover, these condensates are not colocalized to annulate lamellae. Our analysis also revealed that hNup188CTD is sufficient to form condensates and MD simulations revealed the key roles of IDR1-3 for condensation. Notably, hNup93 expression along with hNup188 suppressed the condensate formation. Together, these findings indicate that a structured scaffold nucleoporin can adopt a condensate-forming state via its CTD and Nup93 binding can suppress this phenomenon.

biochemistry↗

bioRxiv2026

The CREB-regulated co-activators 2/3, have a role, in vivo, in osteoblastic gene expression.

Many hormones and substances acting through G-protein coupled receptors and protein kinase A (PKA) activation inhibit the salt-inducible kinases (SIKs) by phosphorylation. SIKs tonically phosphorylate CREB-regulated transcriptional coactivators (CRTC1, 2 and 3), sequestering them in the cytoplasm and, thus, preventing their translocation into the nucleus. Once in the nucleus, CRTCs bind CREB family member transcription factors and enhance their activity. We and others have shown that parathyroid hormone (PTH) activation of PKA and resultant SIK2/3 inhibition allows CRTC2/3 nuclear translocation. One of the major actions of CRTC2/3 in the osteoblast lineage is the regulation of transcription of Rankl, as well as other PTH-controlled genes. However, little is known about the role of these co-activators in the osteoblast lineage in vivo. Here, we have investigated whether there are basal effects in vivo on bone examined at 2 different ages of conditional deletion of these two co-activators in the osteoblast lineage using Col2.3-Cre. We found significant increases in body weight, length, bone mineral density, bone volume/total volume, trabecular thickness and number with decreased trabecular separation in young (2 months old) male mice, all of which dissipated by 6 months of age. Female mice showed minimal changes in the bone phenotype at either age. Nevertheless, there were gene expression changes in bones of both sexes at both ages, and in particular decreases in Rankl, Runx2 and Sost, and accompanying changes in Wnt pathway genes. These effects may explain the changes in the bone phenotype in the young male mice, but it is notable that there is a sexual dimorphism in the action of CRTC2 and CRTC3. Overall, the work supports the data from research in vitro and forms a basis for investigation of the role of these co-activators in PTH action in vivo.

physiology↗

bioRxiv2026

Behavior failures due to previously uncharacterized stimulus-induced modulation appear as neuronal noise

Animals often fail to respond to reliable sensory stimuli, a phenomenon commonly attributed to stochastic neural noise or modulation by internal states. In locusts, looming-evoked jump escape response (JER) fails in ~40% of trials, and these failures correlate with multiplexed features of the descending contralateral movement detector's (DCMD) response1,2. Using Hieroglyphus banian, we show that these failures are predictable from an unobserved "Light-to-Dark transition" (LDT) caused by the procedure in the assay, minutes before the looming stimulus. In the JER assay, LDT induced a long-lasting competing behavioral state, grooming, which suppressed JER. Reducing the amplitude of this transition by illuminating the tunnel decreased grooming and rescued JER. Grooming was reliably induced by LDT in the grasshopper under culture conditions. Electro-mechanical induction of grooming was sufficient to cause JER failure. The grooming state induced by either LDT or electro-mechanical stimulation reduced looming-evoked DCMD responses through a divisive gain modulation while preserving normalized variability. Grooming was rare under natural field conditions. Thus, accounting for previously unobserved stimulus history can explain a substantial component of apparent behavioral failures that would otherwise be attributed to stochastic neural noise.

neuroscience↗

bioRxiv2026

Sex differences in PRDM9-independent fine-scale recombination patterns

Meiotic recombination rates exhibit strong, fine-scale variation along the genome of many eukaryotes. In some animals, including humans, the protein PRDM9 directs recombination toward so-called recombination hotspots. However, in birds and dogs, which have lost PRDM9, hotspots generally occur in promoter sequences called CpG islands. Furthermore, in many species, recombination rates and patterns differ between the sexes, a phenomenon known as heterochiasmy. While sex differences in recombination rates and broad-scale genomic variation are rather well documented, far less is known about differences in fine-scale variation, with no insight from PRDM9-lacking animals. In this study, using thousands of high-resolution crossovers, I demonstrate that fine-scale recombination patterns are globally similar between the sexes in both dogs and barn owls. However, I show that recombination in protein-coding gene promoters is heavily male-biased in both species. Overall, the shared patterns of fine-scale heterochiasmy between these two amniotes shed light on both the sex-specific regulation of recombination and the evolutionary forces that shape it.

genetics↗

bioRxiv2026

Neuro-glial lipid imbalance in a Drosophila model of Amyotrophic Lateral Sclerosis 8

Membrane Contact sites (MCS) have emerged as physiologically relevant zones that coordinate inter-organelle communication and cellular function. VAPB, an ER-resident MCS tethering protein, plays a central role in regulating MCSs through its numerous protein interactors, thereby influencing cellular homeostasis. A pathogenic missense VAPBP56S mutation causes familial Amyotrophic Lateral Sclerosis 8 (ALS8) in humans, with progressive degeneration of motor neurons. The precise mechanisms underlying the motor neurodegeneration remain poorly understood. In this study, we examine lipid imbalance in the brain of a Drosophila model of ALS8 (VAPBP58S). Specifically, we find that lipid homeostasis is disrupted in an age-dependent manner. Strikingly, cholesterol esters and sphingolipids show an age-dependent increase, while cholesterol shows a decrease. Intriguingly, from a cellular perspective, despite the accumulation of triacylglycerols (TAGs) in the brains of VAPBP58S animals, the increased neutral lipid species do not correlate with lipid droplets (LDs), which are fewer in density and smaller in size. Lipid imbalance and progressive motor dysfunction in VAPBP58S animals can be reversed by expressing VAPBWT, suggesting a relationship between VAPB activity and lipid flux. To uncover VAPBs role in lipid homeostasis, we modulate VAPB activity in neurons and glia to dissect out tissue-specific roles. We find that both cell types contribute to lipid homeostasis in differential ways. In glia, LD flux is strongly dependent on VAPB activity, a dependence further recapitulated in cultured human cell lines, suggesting evolutionary conservation of the regulatory mechanism. Thus, we hypothesise that lipid dysregulation constitutes a critical pathogenic feature of ALS8, with the VAPBP56S allele disrupting lipid homeostasis in the neuro-glial axis. Summary StatementThe ER-membrane tethering protein VAPB regulates lipid homeostasis

neuroscience↗

bioRxiv2026

Explaining the rapid evolution of mammalian meiotic recombination proteins

Meiotic recombination -- the exchange of genetic material between parental chromosomes during gamete production -- is critical for fertility, genome stability, and evolutionary adaptation. In eukaryotes, meiotic recombination is carried out by a deeply conserved molecular machinery. Despite this conservation, the sequences of proteins involved in meiotic recombination evolve at a remarkably high rate in mammalian species. Several biological processes have been proposed to explain this rapid evolution, but none have been quantitatively tested. In this study, we analyzed the variation in evolutionary rates of 100 recombination proteins across approximately 400 placental mammals. Our results show that this rapid evolution is primarily driven by lower levels of purifying selection compared to the rest of the proteome. We show that, although selective pressures exerted on recombination proteins are generally shared across mammals, a few recombination proteins exhibit strong variation in selective pressures. Contrary to previous hypotheses, we demonstrate that chromosome number and genome-wide recombination rates do not account for much of this variation. Instead, these variations are primarily associated with chromosome pairing and synapsis proteins, which tend to experience increased selective pressures throughout mammalian evolution, especially in large and long-lived species. This pattern probably reflects more intense selection for stability of chromosome pairing proteins in the oocytes of long-lived species, in which chromosomes sometimes need to stay paired for decades.

evolutionary biology↗

bioRxiv2026

A probabilistic and phylogenetic principal component analysis for modelling high-dimensional trait evolution

Given the ever-increasing availability of highly detailed phenotypes, modelling trait evolution in a multivariate framework is becoming a challenging task. Current phylogenetic comparative methods often struggle with high-dimensional datasets because they suffer computational limitations and interpretability. Here, we propose a maximum likelihood-based approach called Probabilistic and Phylogenetic Principal Components Analysis (P3CA) to circumvent current limitations. This approach is based on a continuous latent variable model, whereby observed traits are explained by a smaller number of unobserved variables that evolve according to a given evolutionary model. We implement the approach under Pagels lambda model using an Expectation-Maximisation algorithm that makes it computationally efficient and allows missing values. Using simulations, we demonstrate that evolutionary parameters are accurately estimated, regardless of phylogenetic signal, the number of traits or the proportion of missing values. The reconstruction of the reduced space is more accurate than the one obtained using other dimensionality reduction approaches, such as phylogenetic and conventional PCA. Likewise, the estimated values for missing data are more accurate than those obtained using current phylogenetic data imputation approaches. We illustrate the approach on a 3D geometric morphometric dataset describing Crocodyliformes skull shapes and containing around 4% of missing data. Our P3CA method unlocks the possibility to analyse and more easily interpret the large-scale multivariate datasets generated in recent decades within a phylogenetic comparative framework.

evolutionary biology↗

bioRxiv2026

Evaluating Spike Antigenicity across Endemic Human Coronavirus Models using Flow Virometry

While SARS-CoV-2 research has advanced rapidly since COVID-19, endemic human coronaviruses (HCoVs) remain comparatively understudied. Tools to phenotype spike (S), the primary antigenic target on coronaviruses, at the single-virion level could improve vaccine design by capturing variation in epitope availability and spike abundance. Here, we establish a calibrated flow virometry (FV) platform to quantify S antigenicity on native endemic (HCoV-229E, HCoV-OC43) and epidemic (SARS-CoV-2) coronaviruses directly in cell culture supernatants. FV revealed cell line-dependent differences in S antigenicity, including receptor-induced changes in epitope accessibility. Comparison of virion-associated S with recombinant stabilized S by ELISA and biolayer interferometry showed consistent binding for HCoV-OC43, MERS-CoV, and SARS-CoV-2, but differences for HCoV-229E, with FV resolving heterogeneity not captured by bulk assays. Finally, FV showed that HCoV-229E from patient-derived air-liquid interface cultures exhibited reduced antibody binding and distinct S antigenicity compared to cell line-derived virions. Together, these findings establish FV as a platform for single-virion analysis of HCoV antigenicity.

microbiology↗

bioRxiv2026

Spatial organization of enzymes and cofactors in synthetic membrane-associated condensates (sMACs)

Cells spatially organize metabolic enzymes to optimize flux through complex biochemical networks. Here, we engineered synthetic Membrane-Associated Condensates (sMACs), artificial assemblies that form on intracellular membranes through liquid-liquid phase separation, to couple metabolic compartmentalization with cofactor partitioning. Using intrinsically disordered regions (IDRs) characterized by simulations and validated by experiments, we identified an IDR sequence, Dbp1n, that selectively enrich NADH and NADPH, establishing distinct local redox microenvironments. At the endoplasmic reticulum (ER) membrane, NADPH-enriched sMACs enhanced cytochrome P450 activity by improving electron transfer and supporting in situ regeneration. At the plasma membrane, NADH-enriched sMACs provided scaffolds for a xylose uptake and assimilation pathway that exploits localized NADH/NAD recycling to improve flux. These results collectively demonstrated that condensate composition and membrane context can be engineered to enhance metabolic functions. sMACs thus provide a modular framework for creating programmable, membrane-associated microreactors, enabling new strategies for metabolic engineering and offering insights into how phase separation can be exploited in living cells.

synthetic biology↗

bioRxiv2026

Stress Granules Buffers Inflammation by Restricting dsRNA-led Mitochondrial Fragmentation

Stress granules (SGs) are dynamic RNA-RBP condensates that form during stress and inflammation, yet how they modulate inflammatory signalling remains unclear. We uncover a rapid, protective SG-mediated mechanism that preserves mitochondrial integrity. During stress and translation inhibition, mitochondrial fragmentation releases double-stranded RNA (dsRNA), which activates PKR and its downstream effector DRP1, generating a self-amplifying loop of mitochondrial fragmentation and inflammation. We find that released dsRNA nucleates nanoSGs within minutes at ER-mitochondria contact sites--the very sites of mitochondrial division. These nanoSGs grow into macroSGs, effectively sequestering PKR-activating dsRNA from the cytosol. By depleting dsRNA, SGs suppress PKR-DRP1-driven positive-feedback inflammation and maintain mitochondrial integrity and function. Our findings reveal SGs as key guardians of mitochondrial homeostasis and position condensate biology at the centre of chronic mitochondrial-driven inflammation relevant to autoimmunity, ageing, and neurodegenerative disease.

cell biology↗

bioRxiv2026

GRASP: A PLANT TRANSFORMATION-INDEPENDENT CRISPR-BASED SYSTEM FOR AFFINITY PURIFICATION OF SPECIFIC CHROMATIN LOCI

Chromatin organization regulates genome stability and gene expression by controlling DNA accessibility to transcription factors and regulatory complexes. DNA-protein interactions are commonly investigated using chromatin immunoprecipitation (ChIP), which relies on specific antibodies often involving technically demanding protocols. CRISPR-Cas technologies have enabled sequence-specific targeting of genomic loci using catalytically inactive Cas9 (dCas9), but most CRISPR-based chromatin capture approaches in plants require transient or stable transformation to express the CRISPR machinery, limiting their applicability across species, tissues and physiological contexts. Here, we present GRASP (Genomic Region Affinity Sequestration by CRISPR-Purification), a transformation-independent strategy for sequence-specific chromatin isolation operating directly on purified plant nuclei. In GRASP, dCas9-gRNA ribonucleoprotein complexes are used to capture predefined genomic regions from chromatin under native conditions, bypassing the need for transgene expression. Using grapevine and tomato as model systems, we demonstrate efficient and highly specific enrichment of target loci, including telomeric repeats as well as low-copy and single-copy genomic regions, with qPCR and NGS validation. These results establish GRASP as a robust and broadly applicable platform for locus-specific chromatin isolation in plants. Beyond sequence-specific DNA isolation, GRASP establishes a versatile platform for potential downstream analyses of locus-associated chromatin components, including protein complexes, distal DNA-DNA interactions and chromatin-associated RNAs, providing new opportunities to investigate regulatory architecture in plant genomes. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/712347v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1d63d52org.highwire.dtl.DTLVardef@53e7f3org.highwire.dtl.DTLVardef@a11b4eorg.highwire.dtl.DTLVardef@107c94a_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2026

Polymer of methyl malonic acid suppress inflammation by downregulating IL-2 through ROS overproduction

Metabolites belonging to the propionate metabolism pathway can regulate immune cell responses in the context of autoimmunity and chronic inflammation. Methyl malonic acid (MMA), a metabolite in this pathway is known to cause dysregulation of T cell oxidative phosphorylation (OXPHOS) and downregulating pro inflammatory T cell effector functions. However, the effects of MMA on T cell signaling and T cell activation is not clearly known. Furthermore, since MMA is a small molecule, using it in the context of therapy remains a problem. It gets metabolized in a short time and millimolar concentrations are required to get effective results. This work describes a novel polymer, 1,6 MMA, synthesized using 1,6 Hexane-diol and MMA, which helps in slow, steady and continuous release of the small molecule. Doses in micromolar ranges generate long lasting and robust immunosuppression of activated T cells via an IL2 dependent mechanism in both human and mice T cells without causing non-specific toxicity. This causes a dysregulated expression of pSTAT5 which eventually enhances BLIMP1 mediated T cell apoptosis. Finally, 1,6 MMA mediated T cell suppression is caused due to increase in mitochondrial ROS production. Extrapolation of our findings in-vivo showed the polymer inhibited autoreactive T cell responses in mice with collagen induced arthritis (CIA). Overall, 1,6 MMA, a novel metabolite polymer, has major therapeutic potential in combating inflammatory disorders.

bioengineering↗

bioRxiv2025

Brain size reduction in dogs was already established at least by the Late Neolithic of western Europe, 5,000 years ago

The timing and causes of brain size reduction in domestic dogs remain uncertain. Using endocasts volume as a proxy for brain size, this study provides a first insight into long-term brain size evolution in the wolf-dog lineage. We compared endocranial volumes of 185 modern and 22 prehistoric wolves and dogs ranging from Western Europe to Australia, and spanning the Pleniglacial (35 Ky BP) to the Late Neolithic (5 Ky BP). Our results reveal that Pleistocene so called "protodogs" show no brain size reduction compared to coeval Pleistocene wolves. Instead, we observed a slightly larger relative endocranial volume in the 35,000-year-old protodog from Goyet, which could suggest increased behavioural flexibility in the presence of humans. This hypothesis needs to be tested further. In contrast, Late Neolithic dogs show a drastic 46% brain size reduction with an endocranial volumes comparable to modern small terrier and toy breeds. The anxious and wary temperaments of these Late Neolithic dogs, induced by the brain tissue reorganization associated with such a size reduction, could have served an alerting purpose, among the many other potential roles dogs could have played within this Late Neolithic socio-ecosystems.

zoology↗

bioRxiv2025

A Precisely Controlled Long-Acting Immunosuppression Platform Enables Prolonged Survival of Vascularized Composite Allografts

Vascularized composite allotransplantation (VCA) restores complex tissue defects but demands lifelong systemic immunosuppression. Oral tacrolimus (TAC) is limited by a narrow therapeutic window, pharmacokinetic variability, adherence challenges, and toxicity. Local delivery could mitigate these issues, yet clinical translation has been hindered by burst release, short duration, and the inability to co-deliver agents. We developed PRECISE (Programmable, REtrievable, Controlled ImmunoSuppression Encapsulator), an injectable, in-situ-forming PLGA depot that achieves long-acting, tightly controlled TAC release via structure-guided co-formulation with drug-binding agents (DBAs). GRAS small molecules (e.g., EGCG, maltotriose) identified by in silico docking and in vitro screening suppressed burst and modulated solvent efflux. Notably, rapamycin (RAPA) served dually as an mTOR inhibitor and a TAC-binding excipient, enabling synchronized dual-agent delivery. PRECISE eliminated burst in vitro and produced coordinated TAC+RAPA release with clinically compatible injectability. In rats, monthly intragraft dosing maintained systemic TAC/RAPA within the therapeutic window ([~]5-10 ng/mL) for >300 days, prolonged hindlimb allograft survival, expanded Tregs, and induced donor-specific hyporesponsiveness. Surgical retrieval of the depot triggered rapid TAC decline, demonstrating reversibility. In a stringent, fully MHC-mismatched porcine VCA model, PRECISE maintained on-target drug levels and extended graft survival beyond 90 days with minimal rejection and preserved vascular integrity. PRECISE is, to our knowledge, the first retrievable, injectable platform to deliver long-acting, dual-agent immunosuppression with controlled kinetics, rapid attainment of therapeutic steady state, and sustained graft protection. Its modular, structure-guided design enables clinical translation across VCA and solid-organ transplantation, delivering precise, durable, and safer immunosuppression.

bioengineering↗

bioRxiv2025

Human Coronavirus HKU1 Neutralizing Monoclonal Antibodies Target Diverse Epitopes Within and Around the TMPRSS2 Receptor Binding Site

Endemic human coronaviruses (HCoVs), such as HCoV-HKU1, account for [~]30% of common colds each year and can cause serious upper and lower respiratory infections, yet no licensed vaccines or therapeutic antibodies target HCoVs. Despite being endemic to the human population, little is known about the antigenic landscape of HCoV-HKU1. Here, we characterized key interactions between the HCoV-HKU1 spike (S) protein and monoclonal antibodies (mAbs) isolated from convalescent HCoV-HKU-1-positive peripheral blood mononuclear cells collected prior to the COVID-19 pandemic. We isolated 14 mAbs that bound distinct regions of S, including the receptor-binding domain (RBD), N-terminal domain, and S2 subunit. Structural and functional studies revealed three groups of RBD-specific mAbs targeting diverse footprints within and around the TMPRSS2 receptor-binding site: (1) H501-022, which recognizes the TMPRSS2-binding site and thereby blocks receptor engagement; (2) H501-008, which binds a distinct epitope outside the TMPRSS2-binding site that is shared with HCoV-OC43; and (3) H501-018, which recognizes both "up" and "down" RBD conformations at a distinct, non-overlapping epitope outside the TMPRSS2-binding site. H501-008 weakly neutralized live HCoV-OC43 in vitro and protected mice against lethal HCoV-OC43 challenge. Notably, the three RBD-specific mAbs potently neutralized HCoV-HKU1 pseudovirus in TMPRSS2-overexpressing cell lines, but exhibited limited neutralizing activity against authentic HCoV-HKU1 infection in primary human airway epithelial cells. Together, these findings structurally define the antigenic landscape within and around the HKU1 receptor-binding site and demonstrate that receptor-binding site recognition alone is insufficient to predict physiologically relevant antibody-mediated neutralization.

microbiology↗

bioRxiv2025

Continuous Production of Recombinant Adeno-Associated Virus in the Insect Cell/Baculovirus Expression Vector System

Continuous production processes may offer significant advantages for biotherapeutic manufacturing, including increased productivity, consistent product quality, reduced facility footprint, and decreased process turnaround time. Despite these benefits, the in-situ formation of defective recombinant baculovirus expression vectors (BEVs) hinders the continuous manufacturing of recombinant adeno-associated viruses (rAAV) in the baculovirus expression vector system. This study investigates an approach of reducing defective viruses through the infusion of standard recombinant baculovirus (rBV) and the compartmentalization of early- and late-stage infected cells, resulting in stable rAAV production. In this study, rAAVs were continuously produced in a series of cascading reactors, comprising a feeder reactor, an infection reactor, and a production reactor. Residence times and transfer rates across the three reactors were optimized based on the production kinetics of rBV and rAAV derived from our mechanistic model. The majority of rBV was produced within the production reactor, thereby reducing the impact of defective viruses in the infection reactor, enabling continuous rAAV production. This study demonstrates the successful implementation of a continuous rAAV production process, yielding over 5x1010 vg/mL per day for 4 weeks. This work represents the first reported continuous rAAV production process utilizing the Sf9/BEVS platform and establishes engineering know-how for overcoming manufacturing challenges associated with rAAV-based gene therapies.

bioengineering↗

bioRxiv2025

Rational Design of Multiclade Coronavirus Spike Immunodominant Domain Nanoparticles Elicit Broad Antibody Responses

Four seasonal endemic human coronaviruses (EhCoVs), HKU1-CoV, OC43-CoV, 229E-CoV, and NL63-CoV, are culprits of mild upper respiratory and periodic severe diseases in vulnerable populations. Despite their prevalence, understanding EhCoVs antigenic and immune signatures remains elusive. SARS-CoV-2 has evolved as the fifth EhCoV, requiring seasonal vaccination in most parts of the world, and currently, no other EhCoV vaccines are available. SARS-CoV-2 co-infection with EhCoVs increases disease severity; thus, combined vaccination may provide increased protection against seasonal EhCoVs overall. Here, we explored Spike (S) receptor binding domain (RBD) vs. N-terminal domain (NTD) B-cell immunodominance in EhCoV-positive convalescent donors and immunogenicity in mice. We found that while antibody and B-cell isotypes were relatively dominant to S NTD, mice immunized with S RBD elicited significantly higher binding and neutralizing antibody (nAb) responses. With that knowledge, we used computational methods to infer that EhCoV S sequences evolve into two main clades and designed chimeric immunodominant domains (IDDs) from both clades for each EhCoV. IDDs were scaffolded onto two-component nanoparticles (NPs) displaying each IDD separately (monovalent IDD NP); three {beta}-EhCoV IDDs (Mosaic-3 IDD NP); or five EhCoVs IDDs (Mosaic-5 IDD NP). Mice immunized with mosaic IDD NPs, but not soluble IDD antigens nor monovalent IDD NPs, elicited potent, broadly cross-reactive binding and neutralizing antibody (Ab) responses against SARS-CoV-2 variants, other EhCoVs, and Sarbecoviruses. System serology revealed that all four IDD immunogens elicited distinct Ab subclasses and Fc-effector functions, with mosaic-5 IDD NPs eliciting the most de novo Ab subclasses, distributions, and broader Fc-mediated immune mechanisms. Dissection of vaccine-immune sera revealed polyclonal Ab responses against multiple non-overlapping cross-reactive S epitopes. Due to elicitation of broad Ab responses with combinatory functionality, IDD NPs open new horizons for developing first-in-class supraseasonal EhCoV vaccine candidates, with potential to decrease frequent SARS-CoV-2 sequence updates and protect against other EhCoVs. Moreover, elicitation of Ab breadth that spans pandemic-threat Sarbecoviruses gives mosaic IDD NPs promise towards pandemic preparedness.

bioengineering↗

bioRxiv2025

A paradigm shift of SERPINA3N in neurobehavioral development and brain injury

Murine serine protease inhibitor clade A member 3N (SERPINA3N) and its human ortholog SERPINA3 are dysregulated in neurological disorders. SERPINA3N has been proposed as a protective factor, enhancing neurobehavioral development under homeostasis and mitigating neuronal/glial and vascular damage under neurological conditions. Here, we employed powerful, non-invasive genetic tools to revisit the concept of SERPINA3N in brain development and injury. Brain-specific SERPINA3N overexpression neither alters neuronal or glial development nor improves cognitive ability under homeostasis. In stark contrast, SERPINA3N drives a pro-inflammatory response to brain injury and exacerbates blood-brain barrier dysfunction. Its overexpression promotes neurodegeneration through apoptosis-mediated neuronal loss and disrupts oligodendroglial differentiation and myelination following neonatal brain injury. Collectively, our findings challenge the prevailing paradigm of SERPINA3N in neurodevelopment and injury, revealing that while SERPINA3N is dispensable for neurobehavioral development, it aggravates neural injury and vascular damage under pathological conditions.

neuroscience↗