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Ojha, A.

Publications and source records attributed to Ojha, A..

At least 19 recordsLinked to original sources

Cryoaerosolization Enables Scalable Vitrification-Based Cell Cryopreservation

Cell therapies hold transformative potential for treating cancer, neurologic disorders, organ failure, diabetes, and other conditions, but their widespread clinical deployment is constrained by the lack of scalable cryopreservation methods that maintain high post-thaw viability. Current standard practice using slow freezing can lead to cell death and impaired cell function. Vitrification offers an alternative by cooling samples rapidly enough to bypass ice formation entirely, better preserving cell structure and function. The high cooling and warming rates required for vitrification have previously been achieved by quenching microliter-scale samples directly into convective cooling and warming baths. Here, we present a cryopreservation platform that overcomes the throughput limitations of existing systems by combining a vibrating orifice aerosol generator with an impinging conical nozzle to generate and confine micrometer-scale droplets mid-flight in liquid nitrogen. This approach mitigates cooling losses due to the inverse Leidenfrost effect, increasing cooling and warming rates by nearly an order of magnitude compared to conventional droplet vitrification, while improving throughput by two orders of magnitude. To test the efficacy of this system, we cryoaerosolized and rewarmed human induced pluripotent stem cells, porcine red blood cells, and human dermal fibroblasts using only 190-25 wt% (2.5-3.7 M) permeating cryoprotective agent, achieving >90% post-thaw viability for HDFs and hiPSCs and 94% recovery for RBCs, with retained colony-forming capacity additionally demonstrated in hiPSCs. This work demonstrates the first scalable vitrification-based cryopreservation method capable of achieving both high cooling ({approx} 200, 000 K min-1) and warming rates ({approx} 1, 000, 000 K min-1) while maintaining the high-throughput processing required ([≥]100 mL h-1) for next-generation cell therapies. Significance StatementCell therapies require robust long-term storage methods to enable widespread clinical deployment. Current approaches utilizing refrigeration or small-scale vitrification cannot meet the scalability and viability requirements for next-generation therapeutics. In this work we demonstrate a cryoaerosolization process that achieves both ultra-rapid cooling rates (>200,000 {degrees}C min-1) and high throughput (>100 mL h-1) by generating micrometer-scale droplets and spraying in a liquid nitrogen impingement stream. Using only as little as 19 wt% cryoprotectant, we achieved >90% cell viability and maintained function, comparable to low-throughput methods, but at two orders of magnitude higher processing rates. We also introduce a just-in-time CPA loading approach that reduces toxicity exposure. This technique enables scalable vitrification-based cryopreservation of large-volume cell products.

bioengineering↗

Developing a Multimodal miR-15a Mimic to Overcome PARP Inhibitor Resistance in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is characterized by high relapse rates and the development of drug resistance, driven by adaptive DNA repair and survival pathways. Here, we develop a multimodal, chemically engineered miRNA therapeutic, MTX-5-FU-Gem-miR-15a, that integrates tumor-suppressive miR-15a activity with chemotherapeutic modifications and tumor-targeting capability. This modified miRNA exhibits potent nanomolar activity across diverse EOC models, including PARP inhibitor-resistant cells, without requiring delivery vehicles. Mechanistically, MTX-5-FU-Gem-miR-15a induces replication stress while suppressing G2/M checkpoint regulators (WEE1 and CHK1), resulting in genomic instability and apoptotic cell death. Transcriptomic and protein-level analyses revealed coordinated suppression of resistance-associated and oncogenic signaling pathways, alongside activation of DNA damage coupled with checkpoint abrogation and potential innate immune response. MTX-5-FU-Gem-miR-15a also demonstrates strong synergy with olaparib and robust antitumor efficacy in vivo. These findings establish a multimodal miRNA-based therapeutic strategy that targets replication stress and checkpoint dependency to overcome PARPi resistance in ovarian cancer.

cancer biology↗

A Scalable fMRI Estimate of Basal Ganglia Brain Tissue Iron for Use in Developmental and Translational Neuroscience

Dopaminergic (DA) function and basal ganglia neurobiology are central to reward learning, motivation, and cognitive control, and dysregulation of these systems contributes to neuropsychiatric conditions that emerge during development. Adolescence is marked by profound reorganization of DAergic basal ganglia circuitry, yet direct in vivo assessment of the DA system remains limited in youth. Brain tissue iron is a developmentally sensitive marker of DA-related neurobiology that can be measured non-invasively via magnetic resonance imaging (MRI). Iron is an essential co-factor for DA synthesis and a foundational metabolic resource that supports cellular metabolism, myelination, and energetic demands of the basal ganglia. T2*-weighted echo-planar imaging (EPI), collected during functional MRI (fMRI), is sensitive to magnetic susceptibility of non-heme brain iron. Leveraging this property, we demonstrate the validity and broad applicability of an iron-sensitive metric that can be derived from conventional single-echo fMRI: {Delta}R2*. In a longitudinal developmental dataset (N = 151; age range 12-31), {Delta}R2* showed high reliability, strong longitudinal stability, and validity via robust convergence with established quantitative relaxometry-based iron measures (R2* and R2). Critically, {Delta}R2* can be retrospectively estimated from extant fMRI data and derived in large-scale consortium data repositories, demonstrated here in the Adolescent Brain and Cognitive Development (ABCD) baseline cohort (N = 8,366; ages 9-11). We show that {Delta}R2* captures known age-related increases in basal ganglia iron, highlighting neurodevelopmental sensitivity at population-scale. Together, these findings establish {Delta}R2* as a reliable, widely accessible marker of basal ganglia iron, enabling scalable investigation of lifespan trajectories and neuropsychiatric risk in existing and future datasets.

neuroscience↗

Geometry-Controlled Diffusion in Bicontinuous Cubic Lipid Networks

Bicontinuous cubic lipid phases exhibit complex internal aqueous networks that strongly influence molecular transport, yet a predictive framework linking internal geometry to effective diffusion remains lacking. In this study, we isolate and quantify the role of geometry alone in governing diffusive transport within bicontinuous cubic lipid networks by modeling diffusion in idealized triply periodic minimal surface geometries, namely the gyroid, diamond, and primitive phases. Monte Carlo random-walk simulations were performed with tracer particles confined to the aqueous domains and reflecting boundaries at the lipid interface, and effective diffusion coefficients were extracted from the long-time mean-squared displacement while tortuosity was independently quantified from geometric path-length statistics. The simulations reveal a clear hierarchy of transport efficiency across cubic phases, with the gyroid exhibiting the highest effective diffusion, followed by the diamond and primitive geometries. Despite identical volume fractions and microscopic diffusion parameters, substantial differences in macroscopic transport emerge solely from geometric connectivity and path elongation, and when normalized diffusion coefficients are plotted against tortuosity, data from all geometries collapse onto a common scaling relationship, identifying tortuosity as a unifying geometric descriptor of transport. These results establish geometry as the dominant control parameter governing diffusion in bicontinuous cubic lipid networks and provide a geometry-only predictive framework that offers a minimal baseline for interpreting experimental transport measurements in cubic lipid phases and supports the rational design of cubosome-based systems with tunable transport properties.

biophysics↗

Developmental variation in dopamine neurobiology, neurocognitive functioning, and impulsivity shape substance use trajectories in youth

Theoretical neurodevelopmental models implicate increases in dopamine (DA) function and limitations in neurocognitive control in risk-taking behavior, including substance use, during the transition from adolescence to adulthood. However, developmental relationships between DA, neurocognitive control, and the emergence of substance use are poorly understood. Here, we tested the role of basal ganglia tissue iron, reflecting DA neurophysiology, as well as impulsivity and inhibitory control in longitudinal developmental trajectories of substance use. We leveraged the National Consortium on Alcohol and NeuroDevelopment in Adolescence and Adulthood (NCANDA-A) cohort, a large, multisite longitudinal neuroimaging study of 807 participants (baseline ages 12 - 22 years old, 50% female, 1 - 9 annual visits per participant, 6164 sessions total). Substance use, inhibitory control, and tissue iron increased non-linearly during adolescence into young adulthood, concurrent with decreases in impulsivity. Non-linear Growth Mixture Models identified four common trajectories of substance use: low (no- or low levels of use across visits; 30% of participants), youth peak (peak use in adolescence/young adulthood followed by declines; 26%), adolescent increasing (early, steep linear increases in use from adolescence into adulthood; 17%), and adult increasing (low use in adolescence, followed by late linear increases into adulthood; 26%). We show that increased substance use was associated with a phenotype of high impulsivity, low inhibitory control, and low basal ganglia tissue iron, particularly in early adolescence in individuals who displayed youth peak patterns in substance use trajectories. These findings highlight that early developmental differences in DA-related neurobiology and associated impulsivity and cognitive control shape distinct trajectories of adolescent substance use, underscoring adolescence as a critical window for the early identification and implementation of neurodevelopmentally sensitive interventions for substance use disorders.

neuroscience↗

Multi-omics integration at cell type resolution uncovers gene-metabolite mechanisms underlying osteoarthritis heterogeneity

Metabolic dysregulation is an important factor for osteoarthritis pathogenesis, but comprehensive studies of underlying mechanisms and pathways are rare. We analyzed newly generated metabolomics data on bone marrow from 119 osteoarthritis patients, along with single-cell transcriptomics data to reconstruct networks of gene-metabolite associations at cell type resolution. Hubs of these networks - cell type-specific as well as pan-cell type hubs - revealed key molecular factors of osteoarthritis heterogeneity. Systems-level analysis of hubs revealed major roles for glycerophospholipid, glycerolipid and sphingolipid metabolism pathways, along with lipid signaling. We used Machine Learning models of gene-metabolite relationships to discover cell types most relevant to each metabolite. Integrative analysis of disease severity scores along with multi-omics data revealed a shift in specific immune cell subtypes in low versus high grade disease. We conclude that leveraging gene-metabolite covariation in a patient cohort can uncover underlying molecular mechanisms, overcoming the challenges posed by high dimensionality of multi-omics data.

bioinformatics↗

Functional analysis of ligand-gated chloride channels in a cnidarian sheds light on the evolution of inhibitory signalling

{psi}-aminobutyric acid (GABA) is the predominant inhibitory transmitter in the vertebrate nervous system. Fast inhibitory signalling is mediated by type A GABA receptors (GABAARs), which form pentameric ligand-gated ion channels. While GABA is also present in plants and prokaryotes, it is unknown when it was first used for fast neuronal transmission. Cnidaria represent a sister group to all Bilateria and possess a variety of putative GABAARs, none of which has been functionally characterized. In this study, we surveyed putative inhibitory ion channel receptors from the model cnidarians Nematostella and Hydra. Phylogenetic analysis revealed a surprising complexity of these receptors. The majority formed a cnidarian-specific radiation with some receptors forming a basal clade. We functionally analyzed seven putative Nematostella GABAARs of this radiation and found that none was activated by GABA or glycine, whereas three were activated by glutamate. Using site-directed mutagenesis, we identified a lysine residue in the canonical ligand-binding pocket that is important for activation by glutamate. Our results identified a group of inhibitory ion channel receptors in Cnidaria that uses glutamate as a ligand. Moreover, they suggest that inhibitory ion channel receptors in Cnidaria massively diversified, which may have been instrumental in the evolution of complex behaviors and sensory processing by the cnidarian nervous system. This work lays the foundation for understanding the diversity and evolution of inhibitory receptors in Cnidaria and the evolution of inhibitory signalling in animal nervous systems.

neuroscience↗

Maturation of striatal dopamine supports the development of habitual behavior through adolescence

Developmental trajectories during the transition from adolescence to adulthood contribute to the establishment of stable, adult forms of operation. Understanding the neural mechanisms underlying this transition is crucial for identifying variability in normal development and the onset of psychiatric disorders, which typically emerge during this time. Habitual behaviors can serve as a model for understanding brain mechanisms underlying the stabilization of adult behavior, while also conferring risk for psychopathologies. Dopaminergic (DA) processes in the basal ganglia are thought to facilitate the formation of habits; however, developmental trajectories of habits and the brain systems supporting them have not been characterized in vivo in developing humans. The current study examined trajectories of habitual behavior from adolescence to adulthood and sought to understand how the maturing striatal DA system may act as a potential mechanism in the process of habit formation. We used data from two longitudinal studies (combined n = 217, 10 - 32 years of age, 1-3 visits each, 320 total sessions) to characterize normative developmental trajectories of basal ganglia tissue iron concentration (a proxy for DA-related neurophysiology) and goal-direct and habitual control behaviors in a two-stage decision-making task. Tissue iron concentrations across the basal ganglia and habitual responding during the two-stage sequential decision-making task both increased with age (all p < 0.001). Importantly, habitual responding was associated with tissue iron concentrations in the putamen (F = 4.34, p = 0.014), such that increases in habitual responding were supported by increases in putamen tissue iron concentration during childhood through late adolescence. Exploratory analyses of further subdivisions of anatomical regions found that this association was specific to the posterior putamen. These results provide novel evidence in humans that habitual behavior continues to mature into adulthood and may be supported by increased specialization of reward systems.

neuroscience↗

Paratransgenesis: The dynamics of engineered Enterobacter symbionts and Cry1Ac-producing Enterobacter for biocontrol of Helicoverpa insect pests in crop production

The potential application of insect gut microorganisms in paratransgenic crop pest management techniques is being investigated. The Helicoverpa gut is known to harbor the symbiont Enterobacter. However, little is known about the dynamics of Enterobacter in the Helicoverpa gut, its interaction with the phyllosphere, and the mechanisms by which it is delivered to this Lepidopteran species. To evaluate the insecticidal activity of Cry1Ac and its capacity to colonize the Helicoverpa gut and the tomato phyllosphere, the symbiont Enterobacter, which was isolated from the Helicoverpa gut, was transformed with constructs 2 (cry1Ac-KmR-pUC18) and 3 (KmR-pGFP). Within 48 hours and 24 hours, respectively, the Helicoverpa gut and tomato phyllosphere were effectively colonized by the GFP-producing construct 3-Enterobacter. In insect bioassays, Cry1Ac-producing constructs 2-E. coli (K12) and 2-Enterobacter were used for diet and leaf-dip testing. Helicoverpa neonates died 86-100% when fed diets supplemented with 10 -10 cells of Cry1Ac-producing construct 2-E. coli (K12), whereas 79-100% died when fed diets supplemented with 10 -10 cells of Cry1Ac-producing construct 2-Enterobacter. Furthermore, when the Cry1Ac-producing construct 2-Enterobacter (0.10 x 109 cells) was applied to the tomato phyllosphere, it caused 100% mortality of neonates within 192 hours. The successful vector modification, genetic transformation, and establishment of recombinant Enterobacter cells in the guts of Helicoverpa larvae and on tomato leaves lay the foundation for advancing a paratransgenic strategy. This engineered bacterium could potentially replace synthetic insecticides for managing lepidopteran pests in crops.

microbiology↗

SpaceExpress: a method for comparative spatial transcriptomics based on intrinsic coordinate systems of tissues

Spatial transcriptomics (ST) technologies have enabled new explorations into the spatial organization of tissues and their functional implications. However, one of the most fundamental analyses - comparative analysis of spatial gene expression across phenotypes - remains a formidable challenge. We introduce SpaceExpress, a novel statistical tool for detecting phenotype-associated changes in spatial expression patterns. SpaceExpress employs a neural network to embed multiple ST samples in a common latent space, enabling robust cross-sample comparisons despite structural and technical variations. It then uses spline regression to test differential spatial expression of genes between conditions, identifying specific regions of the tissue where expression patterns diverge and quantifying the magnitude of those differences, with rigorous false discovery control and handling of multiple replicates per condition. It includes visualization tools to help interpret spatial pattern differences. We demonstrate the tools effectiveness on synthetic and real ST datasets, revealing mechanistic insights into behavior- and development-related neurogenomic changes in honey bees and mice. Our work extends the highly influential paradigm of differential gene expression analysis to spatial omics.

bioinformatics↗

Gap-App: A sex-distinct AI-based predictor for pancreatic ductal adenocarcinoma survival as a web application open to patients and physicians

Withdrawal StatementThe authors have withdrawn this manuscript because the final version, now accepted by Cancer Letters, underwent substantial revisions during peer review that significantly changed the conclusions of the study. The AI models deployed are entirely different from those in the preprint, and the performance metrics originally reported (e.g., accuracy, precision) are no longer valid. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

bioinformatics↗

PIP4K2C inhibition reverses autophagic flux impairment induced by SARS-CoV-2

In search for broad-spectrum antivirals, we discovered a small molecule inhibitor, RMC-113, that potently suppresses the replication of multiple RNA viruses including SARS-CoV-2 in human lung organoids. We demonstrated selective dual inhibition of the lipid kinases PIP4K2C and PIKfyve by RMC-113 and target engagement by its clickable analog. Advanced lipidomics revealed alteration of SARS-CoV-2-induced phosphoinositide signature by RMC-113 and linked its antiviral effect with functional PIP4K2C and PIKfyve inhibition. We discovered PIP4K2Cs roles in SARS-CoV-2 entry, RNA replication, and assembly/egress, validating it as a druggable antiviral target. Integrating proteomics, single-cell transcriptomics, and functional assays revealed that PIP4K2C binds SARS-CoV-2 nonstructural protein 6 and regulates virus-induced impairment of autophagic flux. Reversing this autophagic flux impairment is a mechanism of antiviral action of RMC-113. These findings reveal virus-induced autophagy regulation via PIP4K2C, an understudied kinase, and propose dual inhibition of PIP4K2C and PIKfyve as a candidate strategy to combat emerging viruses.

microbiology↗

Simulation-Driven Design of Stabilized SARS-CoV-2 Spike S2 Immunogens

The full-length prefusion-stabilized SARS-CoV-2 spike (S) is the principal antigen of COVID-19 vaccines. Vaccine efficacy has been impacted by emerging variants of concern that accumulate most of the sequence modifications in the immunodominant S1 subunit. S2, in contrast, is the most evolutionarily conserved region of the spike and can elicit broadly neutralizing and protective antibodies. Yet, S2s usage as an alternative vaccine strategy is hampered by its general instability. Here, we use a simulation-driven approach to design S2-only immunogens stabilized in a closed prefusion conformation. Molecular simulations provide a mechanistic characterization of the S2 trimers opening, informing the design of tryptophan substitutions that impart kinetic and thermodynamic stabilization. Structural characterization via cryo-EM shows the molecular basis of S2 stabilization in the closed prefusion conformation. Informed by molecular simulations and corroborated by experiments, we report an engineered S2 immunogen that exhibits increased protein expression, superior thermostability, and preserved immunogenicity against sarbecoviruses.

biophysics↗

Development of Gemcitabine-Modified miRNA Mimics as Cancer Therapeutics for Pancreatic Ductal Adenocarcinoma

Pancreatic cancer, including its most common subtype, pancreatic adenocarcinoma (PDAC), has the lowest five-year survival rate among patients with pancreatic cancer in the United States. Despite advancements in anticancer treatment, the overall median survival for patients with PDAC has not dramatically improved. Therefore, there is an urgent need to develop new strategies of treatment to address this issue. Non-coding RNAs, including microRNAs (miRNAs), have been found to have major roles in carcinogenesis and the subsequent treatment of various cancer types like PDAC. In this study, we developed a treatment strategy by modifying tumor suppressor miRNAs, hsa-miRNA-15a (miR-15a) and hsa-miRNA-194-1 (miR-194), with the nucleoside analog chemotherapeutic gemcitabine (Gem) to create Gem-modified mimics of miR-15a (Gem-miR-15a) and miR-194 (Gem-miR-194). In a panel of PDAC cell lines, we found that Gem-miR-15a and Gem-miR-194 induce cell cycle arrest and apoptosis, and these mimics are potent inhibitors with IC50 values up to several hundred fold less than their native counterparts or Gem alone. Furthermore, we found that Gem-miR-15a and Gem-miR-194 retained miRNA function by downregulating the expression of several key targets including WEE1, CHK1, BMI1, and YAP1 for Gem-miR-15a, and FOXA1 for Gem-miR-194. We also found that our Gem-modified miRNA mimics exhibit an enhanced efficacy compared to Gem alone in patient-derived PDAC organoids. Furthermore, we observed that Gem-miR-15a significantly inhibits PDAC tumor growth in vivo without observing any noticeable signs of toxicity. Overall, our results demonstrate the therapeutic potential of Gem-modified miRNAs as a treatment strategy for PDAC. One Sentence SummaryYuen and Hwang et. al. have developed a potent therapeutic strategy for patients with pancreatic cancer by modifying microRNAs with gemcitabine.

cancer biology↗

Multivariate and Regional Age-Related Change in Basal Ganglia Iron in Neonates

In the perinatal period, reward and cognitive systems begin trajectories, influencing later psychiatric risk. The basal ganglia is important for reward and cognitive processing but early development has not been fully characterized. To assess age-related development, we used a measure of basal ganglia physiology, specifically brain tissue iron, obtained from nT2* signal in rsfMRI, associated with dopaminergic processing. We used data from the Developing Human Connectome Project (N=464) to assess how moving from the prenatal to the postnatal environment affects rsfMRI nT2*, modeling gestational and postnatal age separately for basal ganglia subregions in linear models. We did not find associations with tissue iron and gestational age [Range: 24.29-42.29] but found positive associations with postnatal age [Range:0-17.14] in the pallidum and putamen, but not the caudate. We tested if there was an interaction between preterm birth and postnatal age, finding early preterm infants (GA<35 weeks) had higher iron levels and changed less over time. To assess multivariate change, we used support vector regression to predict age from voxel-wise-nT2* maps. We could predict postnatal but not gestational age when maps were residualized for the other age term. This provides evidence subregions differentially change with postnatal experience and preterm birth may disrupt trajectories.

neuroscience↗

Puberty contributes to adolescent development of fronto-striatal functional connectivity supporting inhibitory control

Adolescence is defined by puberty and represents a period characterized by neural circuitry maturation (e.g., fronto-striatal systems) facilitating cognitive improvements. Though studies have characterized age-related changes, the extent to which puberty influences maturation of fronto-striatal networks is less known. Here, we combine two longitudinal datasets to characterize the role of puberty in the development of fronto-striatal resting-state functional connectivity (rsFC) and its relationship to inhibitory control in 106 10-18-year-olds. Beyond age effects, we found that puberty was related to decreases in rsFC between the caudate and the anterior vmPFC, rostral and ventral ACC, and v/dlPFC, as well as with rsFC increases between the dlPFC and nucleus accumbens (NAcc) across males and females. Stronger caudate rsFC with the dlPFC and vlPFC during early puberty was associated with worse inhibitory control and slower correct responses, respectively, whereas by late puberty, stronger vlPFC rsFC with the dorsal striatum was associated with faster correct responses. Taken together, our findings suggest that certain fronto-striatal connections are associated with pubertal maturation beyond age effects, which, in turn are related to inhibitory control. We discuss implications of puberty-related fronto-striatal maturation to further our understanding of pubertal effects related to adolescent cognitive and affective neurodevelopment.

neuroscience↗

Hyperglycemia in type 2 diabetes: physiological and clinical implications of a brain centered model.

Classically type 2 diabetes is believed to be a result of insulin resistance and relative insulin deficiency. However, evidences have been accumulating against the insulin resistance centered models. Absence of fasting hyperglycemia by insulin receptor knockouts or insulin suppression, evidence for hyperinsulinemia preceding insulin resistance, the perplexing hyperinsulinemic normoglycemic state, reduced glucose transport to the brain preceding hyperglycemia, signs of vasculopathy preceding hyperglycemia, absent or poor correlation between fasting glucose and insulin, very strong positive correlation between indices of insulin resistance and {beta} cell function in population data are some of the anomalous findings which glucose homeostasis models have not addressed so far. With increasing evidence for neuronal involvement in glucose regulation, we propose a refined model of glucose regulation that considers brain glucose and insulin levels as the ultimate target of homeostasis and combines central and peripheral mechanisms of regulation. A model considering reduced rate of blood to brain transportation of glucose and insulin as primary pathology explains most of the patterns, with or without insulin resistance. Apart from resolving multiple anomalies the model also accounts for the limited and inconsistent success of glucose normalization in effectively reducing diabetic complications and mortality.

physiology↗

An engineered receptor-binding domain improves the immunogenicity of multivalent SARS-CoV-2 vaccines

The SARS-coronavirus 2 (SARS-CoV-2) spike (S) protein mediates viral entry into cells expressing the angiotensin-converting enzyme 2 (ACE2). The S protein engages ACE2 through its receptor-binding domain (RBD), an independently folded 197-amino acid fragment of the 1273-amino acid S-protein protomer. The RBD is the primary SARS-CoV-2 neutralizing epitope and a critical target of any SARS-CoV-2 vaccine. Here we show that this RBD conjugated to each of two carrier proteins elicited more potent neutralizing responses in immunized rodents than did a similarly conjugated proline-stabilized S-protein ectodomain. Nonetheless, the native RBD expresses inefficiently, limiting its usefulness as a vaccine antigen. However, we show that an RBD engineered with four novel glycosylation sites (gRBD) expresses markedly more efficiently, and generates a more potent neutralizing responses as a DNA vaccine antigen, than the wild-type RBD or the full-length S protein, especially when fused to multivalent carriers such as an H. pylori ferritin 24-mer. Further, gRBD is more immunogenic than the wild-type RBD when administered as a subunit protein vaccine. Our data suggest that multivalent gRBD antigens can reduce costs and doses, and improve the immunogenicity, of all major classes of SARS-CoV-2 vaccines.

microbiology↗