Biology subjects

Dai, J.

Publications and source records attributed to Dai, J..

At least 55 records · Page 3Linked to original sources

bioRxiv2024

DNA-SaM, a robust system for large-scale data storage

DNA data storage offers a viable strategy to address the impending data explosion. Early attempts to harness DNA as a storage medium have encountered scalability limitations, largely due to the complexity of codec algorithms, the generation of biochemically harmful sequences and lack of a robust architecture. We present "DNA-SaM", a novel system designed for DNA data storage, which achieves linear computational complexity and strict bio-constraint adherence, ensuring high coding efficiency and fidelity. It encoded data at speeds surpassing classic systems by over 2 orders of magnitude, with this superiority changes across various encoding algorithms. Importantly, DNA-SaM effectively eliminates any sequence that could be deleterious to in vitro and in vivo biochemical processes, including homopolymer runs, tandem repeat motifs, and potential promoter sequences, etc. It also involves an advanced DNA data storage architecture that incorporates a two-tiered indexing system and a novel "storage unit" distribution paradigm for large-scale data storage. It is further validated by practical data storage both in vitro and in vivo with a 100% success rate. Our system is capable of storing data over 1039 PB, which marks a critical advancement in the scalability of DNA-based data storage.

synthetic biology↗

bioRxiv2024

SCAD Delivery Platform: A Novel Approach for Efficient CNS and Extrahepatic Oligonucleotide Therapeutics

Oligonucleotide therapeutics, including antisense oligonucleotides (ASOs) and duplex RNAs like siRNA, saRNA, and miRNA, hold immense potential for treating genetic and acquired diseases by modulating gene expression in a target-specific manner. However, effective delivery to extrahepatic tissues, particularly the central nervous system (CNS), remains a significant challenge. While GalNAc conjugation has enabled liver-specific delivery, leading to several approved siRNA drugs for hepatic targets, CNS delivery lags. ASOs, on the other hand, can self-deliver to the CNS when administered locally, as seen with nusinersen and tofersen. To address this disparity, weve developed the Smart Chemistry Aided Delivery (SCAD) platform which enables duplex RNA delivery by conjugating it to an accessory oligonucleotide (ACO), which acts as an aptamer to mediate protein binding and facilitate cellular uptake. Through extensive screening, we identified an optimal SCAD architecture that demonstrates enhanced cell-free protein binding and in vitro activity. In rodent models, local administration of SCAD-siRNA conjugates resulted in broad biodistribution throughout the CNS and sustained mRNA knockdown for over five months, with a favorable safety profile. The SCAD platform also exhibited efficient delivery to other tissues, including the eye, the lung and the joint. These features support its potential for broader clinical applications, as evidenced by an ongoing trial targeting amyotrophic lateral sclerosis (ALS) associated with mutations in the SOD1 gene. The modular design of SCAD allows it to easily adapt to any duplex RNA, making it a powerful tool for advancing oligonucleotide therapeutics.

neuroscience↗

bioRxiv2024

Uncovering pre-sensitizing agents to FLT3 inhibitors in acute myeloid leukemia with ReSisTrace lineage tracing

While FLT3 inhibitors have significantly improved the treatment of aggressive FLT3-mutated acute myeloid leukemia (AML), the emergence of resistance remains as a major challenge. Here, we applied our recently developed single-cell lineage-tracing method ReSisTrace to identify cells that are pre-resistant or pre-sensitive to FLT3 inhibitors midostaurin and quizartinib in FLT3-ITD-positive AML. By comparing the gene expression profiles of these cells, we unraveled the transcriptional pre-resistance signatures, including G1 to S phase transition 1 (GSPT1) gene. Targeting GSPT1 with the small molecule CC-90009 exhibited strong synergistic effect when combined with FLT3 inhibitors in the FLT3-ITD-mutated MOLM-13 and MV4-11 cell lines and primary AML patient samples. Further, we identified novel compounds that induced transcriptomic changes opposite to the pre-resistance signatures, thereby driving cells to FLT3 inhibitor-sensitive states. Vistusertib (mTOR inhibitor), linsitinib (IGF1R and insulin receptor inhibitor), and meisoindigo (IGF1R and Src family kinase inhibitor), all inhibiting pathways parallel to or downstream of oncogenic FLT3 signaling, were predicted and validated to pre-sensitize the FLT3-ITD-mutated cell lines and primary cells to FLT3 inhibitors. Collectively, these findings demonstrate the validity of our lineage-tracing method in unveiling pre-existing transcriptional features of treatment vulnerability in hematological cancers, and elucidate novel strategies for enhancing FLT3 inhibitor treatment efficacy in FLT3-ITD-positive AML by preventing the emergence of treatment resistance.

cancer biology↗

bioRxiv2024

Generation of cultured beef from bovine embryonic stem cells

Bovine embryonic stem cells (bESCs) serve as an optimal source for generating muscle and fat tissues. However, systematic methodologies for creating cultured beef from bESCs have not yet been reported. Here, we successfully established a bESC line and formulated a specialized culture medium that supports cell pluripotency in both two-dimensional (2D) and three-dimensional (3D) cultures. Additionally, we have also developed serum-free and transgene-free protocols that efficiently differentiate bESCs into muscle and fat cells. These differentiated cells were validated at the transcriptional and protein levels. Furthermore, we devised a method using high moisture stretched plant-based protein scaffolds for incorporating differentiated muscle and fat cells derived from bESCs, producing an innovative plant-cell hybrid cultured beef. These advancements provide a solid foundation for future cultured beef production using pluripotent stem cells.

bioengineering↗

bioRxiv2024

Inhibition of pterygium cell fibrosis by the Rho kinase inhibitor

Pterygium is an ocular disease in which the conjunctival tissue invades the cornea. When the pterygium tissue reaches the pupillary region, the visual function of the patient is affected. Currently, surgical removal is the only effective treatment. However, the recurrence rate of pterygium after surgery can be high. Pterygium is also a health disparity issue since it is more prevalent in the Hispanic and Latino American population. In this study, we determined if the Rho kinase inhibitor can be used to prevent pterygium recurrence since its anti-fibrosis effects have been reported in other cell and tissue types. We cultured primary pterygium cells from pterygium tissues from Hispanic and Latino American, African American, Caucasian, and Asian donors, and used those cells for viability assays, scratch assays, migration assays, and immunostaining of F-actin, fibronectin, collagen I and smooth muscle actin. We found that the Rho kinase inhibitor Y27632 decreased cell viability, wound healing, cell migration, as well as the expression of extracellular matrix and myofibroblast markers in cultured pterygium cells. We believe that Rho kinases inhibitors are a potential post-surgical treatment to prevent pterygium recurrence.

pharmacology and toxicology↗

bioRxiv2024

The global spectrum of tree crown architecture

Trees can differ enormously in their crown architectural traits, such as the scaling relationships that link their height and crown size to their stem diameter. Yet despite the importance of crown architecture in shaping the structure and function of woody ecosystems, we lack a complete picture of what drives this incredible diversity in crown shapes. Using data from >500,000 globally distributed trees, we explored how climate, disturbance, competition, functional traits, and evolutionary history constrain the height, crown size and shape of the worlds tree species. We found that variation in height scaling relationships was primarily controlled by water availability and light competition. Conversely, crown width was predominantly shaped by exposure to wind and fire, while also covarying with other functional traits related to mechanical stability and photosynthesis. Additionally, several plant lineages had crown architectures that defy their environments, such as the exceedingly slender dipterocarps of Southeast Asia, or the extremely wide crowns of legumes in African savannas. Our study charts the global spectrum of tree crown architectural types. It provides a roadmap for integrating crown architecture with vegetation models and remote sensing observations, so that we may better understand the processes that shape the 3D structure of woody ecosystems.

ecology↗

bioRxiv2024

BEGAN: Boltzmann-Reweighted Data Augmentation for Enhanced GAN-Based Molecule Design in Insect Pheromone Receptors

Identifying molecules that bind strongly to target proteins in rational drug design is crucial. Machine learning techniques, such as generative adversarial networks (GAN), are now essential tools for generating such molecules. In this study, we present an enhanced method for molecule generation using objective-reinforced GANs. Specifically, we introduce BEGAN (Boltzmann-Enhanced GAN), a novel approach that adjusts molecule occurrence frequencies during training based on the Boltzmann distribution exp(-{Delta}U/{tau}), where {Delta}U represents the estimated binding free energy derived from docking algorithms and{tau} is a temperature-related scaling hyperparameter. This Boltzmann reweighting process shifts the generation process towards molecules with higher binding affinities, allowing the GAN to explore molecular spaces with superior binding properties. The reweighting process can also be refined through multiple iterations without altering the overall distribution shape. To validate our approach, we apply it to the design of sex pheromone analogs targeting Spodoptera frugiperda pheromone receptor SfruOR16, illustrating that the Boltzmann reweighting significantly increases the likelihood of generating promising sex pheromone analogs with improved binding affinities to SfruOR16, further supported by atomistic molecular dynamics simulations. Furthermore, we conduct a comprehensive investigation into parameter dependencies and propose a reasonable range for the hyperparameter{tau} . Our method offers a promising approach for optimizing molecular generation for enhanced protein binding, potentially increasing the efficiency of drug discovery pipelines. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=186 SRC="FIGDIR/small/611826v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@120c4d3org.highwire.dtl.DTLVardef@5a2034org.highwire.dtl.DTLVardef@f8478aorg.highwire.dtl.DTLVardef@20db79_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

bioRxiv2024

Informing biologically relevant signal from spatial transcriptomic data

Visium is a spatial sequencing technology that utilizes messenger RNA (mRNA) to spatially map gene expression within tissues. Despite its potential, research utilizing deconvolution tools and exploring microenvironment dynamics remains challenging. We address this gap by benchmarking deconvolution tools across diverse biological contexts, identifying optimal methodologies. Subsequently, we introduce a novel pipeline integrating advanced deconvolution techniques and novel tools for reproducible tissue microenvironment analysis. Through this approach, we uncover intricate immune aggregate biology, highlighting the power of our methodology in unraveling complex biological phenomena.

bioinformatics↗

bioRxiv2024

Effect of fumarate and live yeast on methane emissions, rumen fermentation, blood metabolites, and lactation performance in dairy goats

The objective of this study was to evaluate the effects and combined effects of fumarate (32 g/d) and active dry yeast (ADY) (1.5 g/d) on methane emissions, rumen fermentation, microbial community and function, apparent total tract digestibility, blood metabolites, and lactation performance in 28 lactating goats using a randomized complete block design with a 2 x 2 factorial arrangement. Fumarate supplementation inhibited methane emission rates for 3 h post-feeding, while ADY increased the methane emission rates for 2 h pre-feeding, without combined effects between them. Fumarate increased the rumen pH and reduced total VFA concentration without changing the VFA profiles before feeding. Based on two custom dataset of 4,674 metagenome-assembled genomes and 7,758,615 nonredundant genes, neither fumarate nor live yeast influenced the rumen microbial community and function. The addition of fumarate reduced the concentrations of glucose, serum malondialdehyde (MDA), and ammonia in the serum, as well as the activity of insulin, while increasing the activity of serum malate dehydrogenase (MDH) and the levels of urea in both serum and milk. The addition of live yeast reduced serum glucose levels and increased serum MDA concentrations and MUN levels. There was a negative interaction between fumaric acid and live yeast on the levels of urea nitrogen in serum and milk. ConclusionsThe methane inhibition effect of fumaric acid persists for 3 h post-feeding, reflecting its retention or metabolism time in the rumen. Fumaric acid enhances the TCA cycle and the urea cycle in dairy goats, thereby improving energy utilization efficiency and reducing the risk of ammonia toxicity.

microbiology↗

bioRxiv2024

Global Scientific Trends in Organoids from 2004 to 2023: A Data Bibliometric and Visualized Analysis

To conduct a bibliometric analysis of organoids to describe international research trends and visualize current research directions. This cross-sectional bibliometric analysis examined the development of organoid research from 2004 to 2023. The current study used VOS-viewer to assess and analyze 13,174 documents. Literature data were collected on a specific date (Feb 19, 2024) and downloaded in plain text from Web of Science Core Collection. In this paper, 13,174 organoid papers were retrieved from Web of Science Core Collection. There were only 114 organoid studies in 2004, and from 2015 onward, the number of annual publications on this topic began to proliferate, reaching 10,023 from 2019 to 2023, accounting for as much as 76.1% of the total number of published papers. The United States proudly leads the way in both the volume of articles published and the number of citations garnered, standing tall as the undisputed frontrunner. Among the illustrious institutions, Harvard University and the University of Washington are among the most prolific. Hans Clevers has worked with 121 prolific authors and has the most publications. With the use of organoids in cancer modeling, drug screening, and regenerative medicine, organoid technology has attracted much attention in medicine, and the significant increase in the number of published papers and citations signifies the expanding influence and global collaboration in the field of organoid research. This study contributes to our understanding of current trends and potential future advances in the field of organoid research by identifying five distinct clusters in the field.

cancer biology↗

bioRxiv2024

Chronic innate immune impairment and ZIKV persistence in the gastrointestinal tract during SIV infection in pigtail macaques

Mosquito borne flaviviruses, including dengue (DENV) and Zika (ZIKV) viruses, have caused global epidemics in areas with high HIV prevalence due to the expanded geographic range of arthropod vectors. Despite the occurrence of large flavivirus outbreaks in countries with high HIV prevalence, there is little knowledge regarding the effects of flavivirus infection in people living with HIV (PLWH). Here, we use a pigtail macaque model of HIV/AIDS to investigate the impact of simian immunodeficiency virus (SIV)-induced immunosuppression on ZIKV replication and pathogenesis. Early acute SIV infection induced expansion of peripheral ZIKV cellular targets and increased innate immune activation and peripheral blood mononuclear cells (PBMC) from SIV infected macaques were less permissive to ZIKV infection in vitro. In SIV-ZIKV co-infected animals, we found increased persistence of ZIKV in the periphery and tissues corresponding to alterations in innate cellular (monocytes, neutrophils) recruitment to the blood and tissues, decreased anti-ZIKV immunity, and chronic peripheral inflammatory and innate immune gene expression. Collectively, these findings suggest that untreated SIV infection may impair cellular innate responses and create an environment of chronic immune activation that promotes prolonged ZIKV viremia and persistence in the gastrointestinal tract. These results suggest that PLWH or other immunocompromised individuals could be at a higher risk for chronic ZIKV replication, which in turn could increase the timeframe of ZIKV transmission. Thus, PLWH are important populations to target during the deployment of vaccine and treatment strategies against ZIKV. Author SummaryFlaviviruses, including Zika virus (ZIKV), cause global epidemics in areas with high HIV prevalence. Yet questions remain as to whether ZIKV disease is altered during an immunocompromised state and the potential immune mechanisms contributing to enhanced disease. This is essential to our understanding of ZIKV disease in people living with HIV (PLWH). Here, we use a non-human primate (NHP) model of HIV/AIDS to investigate the impact of immune suppression on ZIKV replication and pathogenesis. The use of the NHP model was critical for the assessment of longitudinal specimens across tissues that are active sites of flavivirus replication and host immune responses. This study broadly demonstrates that ZIKV pathogenesis is altered and more persistent in states of immunosuppression. Collectively, this study suggests that in PLWH and immunocompromised individuals, other arboviruses, including dengue and West Nile viruses, could similarly alter pathogenesis and/or viral peristance in tissues. Furthermore, this study highlights the need to prioritize immunocompromised individuals in the design and rollout of vaccines against arboviral diseases.

immunology↗

bioRxiv2024

Characterization, enrichment, and computational modeling of cross-linked actin networks in trabecular meshwork cells

PurposeCross-linked actin networks (CLANs) are prevalent in the glaucomatous trabecular meshwork (TM), yet their role in ocular hypertension remains unclear. We used a human TM cell line that spontaneously forms fluorescently-labeled CLANs (GTM3L) to explore the origin of CLANs, developed techniques to increase CLAN incidence in GMT3L cells, and computationally studied the biomechanical properties of CLAN-containing cells. MethodsGTM3L cells were fluorescently sorted for viral copy number analysis. CLAN incidence was increased by (i) differential sorting of cells by adhesion, (ii) cell deswelling, and (iii) cell selection based on cell stiffness. GTM3L cells were also cultured on glass or soft hydrogel to determine substrate stiffness effects on CLAN incidence. Computational models were constructed to mimic and study the biomechanical properties of CLANs. ResultsAll GTM3L cells had an average of 1 viral copy per cell. LifeAct-GFP expression level did not affect CLAN incidence rate, but CLAN rate was increased from [~]0.28% to [~]50% by a combination of adhesion selection, cell deswelling, and cell stiffness-based sorting. Further, GTM3L cells formed more CLANs on a stiff vs. a soft substrate. Computational modeling predicted that CLANs contribute to higher cell stiffness, including increased resistance of the nucleus to tensile stress when CLANs are physically linked to the nucleus. ConclusionsIt is possible to greatly enhance CLAN incidence in GTM3L cells. CLANs are mechanosensitive structures that affect cell biomechanical properties. Further research is needed to determine the effect of CLANs on TM biomechanics and mechanobiology as well as the etiology of CLAN formation in the TM.

cell biology↗

bioRxiv2024

High-throughput drug screening for inhibition of influenza A virus infection based on human SIRT1 promoter and Genipin suppressing influenza A virus by activation of AMPK-SIRT1-PGC-1α signaling pathway

The energy metabolism crisis is considered an important risk factor for severe influenza A virus (IAV) infection. During virus replication, the host cells "metabolic reprogramming" is beneficial for increasing the energy demand of the virus. SIRT1 plays a major role in altering metabolic reprogramming, and upregulation of SIRT1 expression can defend against viral infection. This study established a high-throughput drug screening method for human SIRT1 promoter. Nine natural medicines were selected from 134 traditional Chinese medicines. Among them, the activity of Gardenia jasminoides Ellis was relatively high. Further research has found that the plant extract and its active compound Genipin and its derivatives can significantly inhibit IAV replication, improve the survival rate of infected mice, and inhibit pneumonia. In addition, Genipin significantly increased the levels of energy metabolism core regulatory factors SIRT1, PPAR {gamma}, PGC-1 , and p-AMPK, inhibited IAV induced activation of MAPKs and NF-{kappa}B, and alleviated inflammatory response. The pharmacological antagonists of SIRT1 and PGC-1 , as well as siRNA, significantly counteracted the effects of Genipin on IAV replication and inflammation. In summary, we found that Genipin and its derivatives could significantly inhibit IAV replication and inflammation, possibly by activating the AMPK-SIRT1-PGC-1 signaling pathway and altering metabolic reprogramming.

pharmacology and toxicology↗

bioRxiv2024

Composite Hedges Nanopores: A High INDEL-Correcting Codec System for Rapid and Portable DNA Data Readout

DNA, as the origin for the genetic information flow, has also been a compelling alternative to non-volatile information storage medium. Reading digital information from this highly dense but lightweighted medium nowadays relied on conventional next-generation sequencing (NGS), which involves wash and read cycles for synchronization and the indel (insertion and deletion) errors rarely occur. However, these time-consuming cycles hinder the future of real-time data retrieval. Nanopore sequencing holds the promise to overcome the efficiency problem, but high indel error rates lead to the requirement of large amount of high-quality data for accurate readout using emerging NGS-based codec systems. Here we introduce Composite Hedges Nanopores (CHN), a nanopore-based codec scheme tailored for real-time data retrieval, capable of handling indel rates up to 15.9% and substitution rates up to 7.8%. The overall information density can be doubled from 0.59 to 1.17 by utilizing a degenerated eight-letter alphabet, where one composite strand will be projected into eight normal strands. We demonstrate that sequencing times of 20 and 120 minutes were sufficient for processing representative text and image files (7 and 115 composite strands), respectively. The time-diminishing deviations are mainly originated from the extremely uneven abundance among the composite strands (cross-group variation) as well as the huge inequality among the normal strands (in-group variation). Moreover, to achieve complete data recovery, it is estimated that text and image data require 4x and 8x physical redundancy (coverage) of composite strands, respectively. Our CHN codec system excels on both molecular design and equalized dictionary usage, laying a solid foundation for nucleic acid-based data retrieval and encoding approaching to real-time, applicable in both cloud and edge computing systems.

bioinformatics↗

bioRxiv2024

CA1i pyramidal neurons mediate the role of NMDA receptor subunit GluN3A in depressive behavior and D-serine anti-depression

The hippocampus is a highly complex structure, defined by profound structural, functional, and molecular heterogeneity. The GluN3A subunit, which forms non-classic N-methyl-D-aspartate receptors (NMDARs), is enriched in the hippocampal CA1 subregion and has a poorly understood functional role, especially in stress-related behavioral regulation. Here, we employed chronic social defeat stress (CSDS) and GluN3A knockout (KO) mouse models combined with behavioral, molecular, genetic, pharmacological, and circuit-level analyses to investigate the role of hippocampal GluN3A in stress coping. We found that CSDS selectively reduced GluN3A expression in the intermediate CA1 (CA1i) region. Decreased GluN3A expression in CA1i, from either stress or genetic deletion, promoted passive coping behaviors, whereas overexpression of GluN3A in CA1i reversed the phenotype under both conditions. Mechanistically, consistent with GluN3A enrichment in pyramidal neurons, c-fos staining and fiber photometry revealed that GluN3A was essential for CA1i pyramidal neuronal activation during coping behaviors. Further chemogenetic manipulations demonstrated that activating CA1i neurons facilitated active coping, while inhibition induced passivity. Moreover, local administration of D-serine, an agonist of GluN3A-containing NMDARs, rapidly shifted coping behavior from passive to active by activating CA1i neurons via GluN3A-dependent mechanisms. Circuit tracing revealed that CA1i neurons project to multiple sub-hippocampal and cortico-limbic regions, and GluN3A overexpression selectively enhanced downstream neuronal activity in CA3 and infralimbic cortex, but not in the nucleus accumbens. Together, these findings identify GluN3A as a key molecule linking hippocampal subregional specialization with adaptive stress coping, and suggest that the rapid, resilience-promoting effects of D-serine are also GluN3A-dependent.

neuroscience↗

bioRxiv2024

Development of an engineered extracellular vesicles-based vaccine platform for combined delivery of mRNA and protein to induce functional immunity

mRNA incorporated in lipid nanoparticles (LNPs) became a new class of vaccine modality for induction of immunity against COVID-19 and ushered in a new era in vaccine development. Here, we report a novel, easy-to-execute, and cost effective engineered extracellular vesicles (EVs)-based combined mRNA and protein vaccine platform (EVX-M+P vaccine) and explore its utility in proof-of-concept immunity studies in the settings of cancer and infectious disease. As a first example, we engineered EVs to contain ovalbumin mRNA and protein (EVOvaM+P) to serve as cancer vaccine against ovalbumin-expressing melanoma tumors. EVOvaM+P administration to mice with established melanoma tumors resulted in tumor regression associated with effective humoral and adaptive immune responses. As a second example, we generated engineered EVs, natural nanoparticle carriers shed by all cells, that contain mRNA and protein Spike (S) protein to serve as a combined mRNA and protein vaccine (EVSpikeM+P vaccine) against SARS-CoV-2 infection. EVSpikeM+P vaccine administration in mice and baboons elicited robust production of neutralizing IgG antibodies against RBD (receptor binding domain) of S protein and S protein specific T cell responses. Our proof-of-concept study describes a new platform with an ability for rapid development of combination mRNA and protein vaccines employing EVs for deployment against cancer and other diseases.

immunology↗

bioRxiv2024

A 10-valent composite mRNA vaccine against both influenza and COVID-19

The COVID-19 pandemic caused by SARS-CoV-2 viruses has had a persistent and significant impact on global public health for four years. Recently, there has been a resurgence of seasonal influenza transmission worldwide. The co-circulation of SARS-CoV-2 and seasonal influenza viruses results in a dual burden on communities. Additionally, the pandemic potential of zoonotic influenza viruses, such as avian Influenza A/H5N1 and A/H7N9, remains a concern. Therefore, a combined vaccine against all these respiratory diseases is in urgent need. mRNA vaccines, with their superior efficacy, speed in development, flexibility, and cost-effectiveness, offer a promising solution for such infectious diseases and potential future pandemics. In this study, we present FLUCOV-10, a novel 10-valent mRNA vaccine created from our proven platform. This vaccine encodes hemagglutinin (HA) proteins from four seasonal influenza viruses and two avian influenza viruses with pandemic potential, as well as spike proteins from four SARS-CoV-2 variants. A two-dose immunization with the FLUCOV-10 elicited robust immune responses in mice, producing IgG antibodies, neutralizing antibodies, and antigen-specific cellular immune responses against all the vaccine-matched viruses of influenza and SARS-CoV-2. Remarkably, the FLUCOV-10 immunization provided complete protection in mouse models against both homologous and heterologous strains of influenza and SARS-CoV-2. These results highlight the potential of FLUCOV-10 as an effective vaccine candidate for the prevention of influenza and COVID-19. Author summaryAmidst the ongoing and emerging respiratory viral threats, particularly the concurrent and sequential spread of SARS-CoV-2 and influenza, our research introduces FLUCOV-10. This novel mRNA-based combination vaccine, designed to counteract both influenza and COVID-19, by incorporating genes for surface glycoproteins from various influenza viruses and SARS-CoV-2 variants. This combination vaccine showed highly effective in preclinical trials, generating strong immune responses, and ensuring protection against both matching and heterologous strains of influenza and SARS-CoV-2. FLUCOV-10 represents a significant step forward in our ability to address respiratory viral threats, showcasing potential as a singular, adaptable vaccine solution for global health challenges.

microbiology↗

bioRxiv2024

Efficient overexpression and purification of SARS-CoV-2 Nucleocapsid proteins in Escherichia coli

The fundamental biology of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (Ncap), its use in diagnostic assays and its potential application as a vaccine component have received considerable attention since the outbreak of the Covid19 pandemic in late 2019. Here we report the scalable expression and purification of soluble, immunologically active, SARS-CoV-2 Ncap in Escherichia coli. Codon-optimised synthetic genes encoding the original Ncap sequence and four common variants with an N-terminal 6His affinity tag (sequence MHHHHHHG) were cloned into an inducible expression vector carrying a regulated bacteriophage T5 synthetic promoter controlled by lac operator binding sites. The constructs were used to express Ncap proteins and protocols developed which allow efficient production of purified Ncap with yields of over 200 mg per litre of culture media. These proteins were deployed in ELISA assays to allow comparison of their responses to human sera. Our results suggest that there was no detectable difference between the 6His-tagged and untagged original Ncap proteins but there may be a slight loss of sensitivity of sera to other Ncap isolates.

biochemistry↗