Effects of salinity and betaine addition on anaerobic granular sludge properties and microbial community succession patterns in organic saline wastewater.

In this study, the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities, sludge characteristics and microbial communities were investigated. The increase in salinity resulted in a decrease in particle size of the granular sludge, which was concentrated in the range of 0.5-1.0 mm. The content of EPS (extracellular polymeric substances) in the granular sludge gradually increased with increasing salinity and the addition of betaine (a typical compatible solute). Meanwhile, the microbial community structure was significantly affected by salinity, with high salinity reducing the diversity of bacteria. At higher salinity, Patescibacteria and Proteobacteria gradually became the dominant phylum, with relative abundance increasing to 13.53% and 12.16% at 20 g/L salinity. Desulfobacterota and its subordinate Desulfovibrio, which secrete EPS in large quantities, dominated significantly after betaine addition.Their relative abundance reached 13.65% and 7.86% at phylum level and genus level. The effect of these changes on the treated effluent was shown as the average chemical oxygen demand (COD) removal rate decreased from 82.10% to 79.71%, 78.01%, 68.51% and 64.55% when the salinity gradually increased from 2 g/L to 6, 10, 16 and 20 g/L. At the salinity of 20 g/L, average COD removal increased to 71.65% by the addition of 2 mmol/L betaine. The gradient elevated salinity and the exogenous addition of betaine played an important role in achieving stability of the anaerobic system in a highly saline environment, which provided a feasible strategy for anaerobic treatment of organic saline wastewater.

Sargassum mcclurei Mitigating Methane Emissions and Affecting Rumen Microbial Community in In Vitro Rumen Fermentation.

Methane emissions from ruminants significantly contribute to greenhouse gases. This study explores the methane mitigation effect and mechanism of S. mcclurei through in vitro rumen fermentation, aiming to establish its potential as a feed additive. We investigated the effects of freeze-dried and dried S. mcclurei at supplementation levels of 2%, 5%, and 10% of dry matter on nutrient degradation, ruminal fermentation, methane inhibition, and microbial community structure in in vitro rumen fermentation. The freeze-dried S. mcclurei at 2% supplementation significantly reduced CH4 emissions by 18.85% and enhanced crude protein degradability. However, total VFA and acetate concentrations were lower in both treatments compared to the control. The microbial shifts included a decrease in Lachnospiraceae_NK3A20_group and Ruminococcus and an increase in Selenomonas, Succinivibrio, and Saccharofermentans, promoting propionate production. Additionally, a significant reduction in Methanomicrobium was observed, indicating direct methane mitigation. Freeze-dried S. mcclurei at a 2% supplementation level shows potential as an effective methane mitigation strategy with minimal impact on rumen fermentation, supported by detailed insights into microbial community changes.

Structural basis of the monkeypox virus mRNA cap N7 methyltransferase complex.

The global outbreak of Mpox, caused by the monkeypox virus (MPXV), has attracted international attention and become another major infectious disease event after COVID-19. The mRNA cap N7 methyltransferase (RNMT) of MPXV methylates the N7 position of the added guanosine to the 5'-cap structure of mRNAs and plays a vital role in evading host antiviral immunity. MPXV RNMT is composed of the large subunit E1 and the small subunit E12. How E1 and E12 of MPXV assembly remains unclear. Here, we report the crystal structures of E12, the MTase domain of E1 with E12 (E1CTD-E12) complex, and the E1CTD-E12-SAM ternary complex, revealing the detailed conformations of critical residues and the structural changes upon E12 binding to E1. Functional studies suggest that E1CTD N-terminal extension (Asp545-Arg562) and the small subunit E12 play an essential role in the binding process of SAM. Structural comparison of the AlphaFold2-predicted E1, E1CTD-E12 complex, and the homologous D1-D12 complex of vaccinia virus (VACV) indicates an allosteric activating effect of E1 in MPXV. Our findings provide the structural basis for the MTase activity stimulation of the E1-E12 complex and suggest a potential interface for screening the anti-poxvirus inhibitors.

DOS-3 mediates cell-non-autonomous DAF-16/FOXO activity in antagonizing age-related loss of C. elegans germline stem/progenitor cells.

Age-related depletion of stem cells causes tissue degeneration and failure to tissue regeneration, driving aging at the organismal level. Previously we reported a cell-non-autonomous DAF-16/FOXO activity in antagonizing the age-related loss of germline stem/progenitor cells (GSPCs) in C. elegans, indicating that regulation of stem cell aging occurs at the organ system level. Here we discover the molecular effector that links the cell-non-autonomous DAF-16/FOXO activity to GSPC maintenance over time by performing a tissue-specific DAF-16/FOXO transcriptome analysis. Our data show that dos-3, which encodes a non-canonical Notch ligand, is a direct transcriptional target of DAF-16/FOXO and mediates the effect of the cell-non-autonomous DAF-16/FOXO activity on GSPC maintenance through activating Notch signaling in the germ line. Importantly, expression of a human homologous protein can functionally substitute for DOS-3 in this scenario. As Notch signaling controls the specification of many tissue stem cells, similar mechanisms may exist in other aging stem cell systems.

The Identification of RPL4 as a Hub Gene Associated with Goat Litter Size via Weighted Gene Co-Expression Network Analysis.

Reproduction in goats is a highly complex and dynamic process of life regulation, involving coordinated regulation from various aspects such as central nervous system regulation, reproductive system development, oocyte maturation, and fertilized egg development. In recent years, researchers have identified numerous genes associated with goat reproductive performance through high-throughput sequencing, single-cell sequencing, gene knockout, and other techniques. However, there is still an urgent need to explore marker genes related to goat reproductive performance. In this study, a single-cell RNA sequencing dataset of oocytes (GSE136005) was obtained from the Gene Expression Omnibus (GEO) database. Weighted Gene Co-expression Network Analysis (WGCNA) was utilized to identify modules highly correlated with goat litter size. Through gene function enrichment analysis, it was found that genes within the modules were mainly enriched in adhesive junctions, cell cycle, and other signaling pathways. Additionally, the top 30 hub genes with the highest connectivity in WGCNA were identified. Subsequently, using Protein-Protein Interaction (PPI) network analysis, the top 30 genes with the highest connectivity within the modules were identified. The intersection of hub genes, key genes in the PPI network, and differentially expressed genes (DEGs) led to the identification of the RPL4 gene as a key marker gene associated with reproductive capacity in goat oocytes. Overall, our study reveals that the RPL4 gene in oocytes holds promise as a biological marker for assessing goat litter size, deepening our understanding of the regulatory mechanisms underlying goat reproductive performance.

Population identification and genetic diversity analysis of Fritillaria ussuriensis (Fritillaria) based on chloroplast genes atpF and petB.

The chloroplast genomes of five Fritillaria ussuriensis materials from different production areas were comparatively analyzed, atpF and petB were screened as specific DNA barcodes, and the population identification and genetic diversity of F. ussuriensis were analyzed based on them. The F. ussuriensis chloroplast genome showed a total length of 151 515-151 548 bp with a typical tetrad structure and encoded 130 genes. atpF and petB were used to amplify 183 samples from 13 populations, and they could identify 6 and 9 haplotypes, respectively. Joint analysis of the two sequences revealed 18 haplotypes, named H1-H18, with the most widely distributed and most abundant being H4. Ten haplotypes were unique for 7 populations that they could be used to distinguish from others. Haplotype diversity and nucleotide diversity were 0.99 and 2.09 × 10-3, respectively, indicating the genetic diversity was relatively rich. The results of the intermediary adjacency network showed that H5 was the oldest haplotype, and stellate radiation was centered around it, indicating that population expansion occurred in genuine production areas. This study lays a theoretical foundation for the population identification, genetic evolution, and breed selection of F. ussuriensis.

Evolution and diversity of biomineralized columnar architecture in early Cambrian phosphatic-shelled brachiopods.

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell structures is the organo-phosphatic cylindrical column exclusive to phosphatic-shelled brachiopods, including both crown and stem groups. However, the complexity, diversity, and biomineralization processes of these microscopic columns are far from clear in brachiopod ancestors. Here, exquisitely well-preserved columnar shell ultrastructures are reported for the first time in the earliest eoobolids Latusobolus xiaoyangbaensis gen. et sp. nov. and Eoobolus acutulus sp. nov. from the Cambrian Series 2 Shuijingtuo Formation of South China. The hierarchical shell architectures, epithelial cell moulds, and the shape and size of cylindrical columns are scrutinised in these new species. Their calcium phosphate-based biomineralized shells are mainly composed of stacked sandwich columnar units. The secretion and construction of the stacked sandwich model of columnar architecture, which played a significant role in the evolution of linguliforms, is highly biologically controlled and organic-matrix mediated. Furthermore, a continuous transformation of anatomic features resulting from the growth of diverse columnar shells is revealed between Eoobolidae, Lingulellotretidae, and Acrotretida, shedding new light on the evolutionary growth and adaptive innovation of biomineralized columnar architecture among early phosphatic-shelled brachiopods during the Cambrian explosion.

Oxygen-producing and pH-responsive targeted DNA nanoflowers for enhanced chemo-sonodynamic therapy of lung cancer.

Lung cancer is the deadliest kind of cancer in the world, and the hypoxic tumor microenvironment can significantly lower the sensitivity of chemotherapeutic drugs and limit the efficacy of different therapeutic approaches. In order to overcome these problems, we have designed a drug-loaded targeted DNA nanoflowers encoding AS1411 aptamer and encapsulating chemotherapeutic drug doxorubicin and oxygen-producing drug horseradish peroxidase (DOX/HRP-DFs). These nanoflowers can release drugs in response to acidic tumor microenvironment and alleviate tumor tissue hypoxia, enhancing the therapeutic effects of chemotherapy synergistic with sonodynamic therapy. Owing to the encoded drug-loading sequence, the doxorubicin loading rate of DNA nanoflowers reached 73.24 ± 3.45%, and the drug could be released quickly by disintegrating in an acidic environment. Furthermore, the AS1411 aptamer endowed DNA nanoflowers with exceptional tumor targeting properties, which increased the concentration of chemotherapeutic drug doxorubicin in tumor cells. It is noteworthy that both in vitro and in vivo experiments demonstrated DNA nanoflowers could considerably improve the hypoxia of tumor cells, which enabled the generation of sufficient reactive oxygen species in combination with ultrasound, significantly enhancing the therapeutic effect of sonodynamic therapy and evidently inhibiting tumor growth and metastasis. Overall, this DNA nanoflowers delivery system offers a promising approach for treating lung cancer.

The Internal Anatomy and Water Current System of Cambrian Archaeocyaths of South China.

Archaeocyaths are a group of extinct filter feeders that flourished in the early Cambrian period and occupied an important position in the evolution of basal fauna and the early marine ecosystem. However, the detailed morphological and anatomical information of this group are still unclear due to insufficient fossil material and limited experimental analyses. Here, we report exquisitely preserved phosphatized archaeocyathan fossil cups, ca. 515 million years old, from the top of the Shuijingtuo Formation (Series 2, Stage 3) and the Xiannüdong Formation (Series 2, Stage 3) of the Yangtze Platform, South China. Detailed observation of their external morphology via scanning electron microscopy (SEM) and micro-computed tomography (Micro-CT) analysis revealed detailed information of their internal structure. They have a typical double-walled cup, with the perforated inner and outer walls concentrically distributed, but the structure between the two walls differs. The inverted cone-shaped cups have radially distributed septa between the walls. Perforated septa connect the two walls. The low and columnar cups have canals between the two walls, forming the network. These pores and cavities constitute an important component of the water current system (pumping and filtering water with a network of canals and chambers) and influence the process of filtration in the cup. In comparison to traditional thin-section analysis, the combination of SEM and Micro-CT analysis on phosphatized archaeocyaths presented in this study further explored the detailed internal structure and finely reconstructed the microscopic overall morphology and anatomy, which provide important information to help us understand the systematic taxonomy, anatomy, and morphology of archaeocyaths during the Cambrian period.

A clean and sustainable method for recycling of lithium from spent lithium iron phosphate battery powder by using formic acid and oxygen.

With the widespread adoption of lithium iron phosphate (LiFePO4) batteries, the imperative recycling of LiFePO4 batteries waste presents formidable challenges in resource recovery, environmental preservation, and socio-economic advancement. Given the current overall lithium recovery rate in LiFePO4 batteries is below 1 %, there is a compelling demand for an eco-friendly, cost-efficient, and sustainable solution. This study introduces a green and sustainable recycling method that employs environmentally benign formic acid and readily available oxygen as reaction agents for selectively leaching lithium from discarded lithium iron phosphate powder. Formic acid was employed as the leaching agent, and oxygen served as the oxidizing agent. Utilizing a single-factor variable approach, various factors including formic acid concentration, oxygen flow rate, leaching time, liquid-to-solid ratio, and reaction temperature were individually investigated. Moreover, the feasibility of this method was explored mechanistically by analyzing E-pH diagrams of the Li-Fe-P-H2O system. Results demonstrate that under conditions of 2.5 mol/L formic acid concentration, 0.12 L/min oxygen flow rate, 25 mL/g liquid-to-solid ratio, 70 °C reaction temperature, and 3 h reaction time, lithium leaching efficiency exceeds 99.9 %, with iron leaching efficiency only at 1.7 %. Moreover, we also explored using air instead of oxygen as the oxidant and get the excellent lithium leaching rate (97.81 %) and low iron leaching rate (4.81 %), which shows the outstanding selectivity. Furthermore, the environmentally benign composition of the chemical reagents, comprising only C, H, and O elements, establishes it as a genuinely green and sustainable technology for secondary resource recovery. It can be considered as a highly environmentally friendly, cost-effective, and efficient approach. Nevertheless, in the current context of carbon neutrality and sustainable development, this method undoubtedly holds excellent prospects for industrialization.

Comparative study of Fe2+/H2O2 and Fe2+/persulfate systems on the pre-treatment process of real pharmaceutical wastewater.

Advanced oxidation technologies based on hydroxyl radical (•OH) and sulfate radical (SO4-•) are two common types of advanced oxidation technologies, but there are not many reports on the application of advanced oxidation methods in actual wastewater pretreatment. This article compares the pre-treatment performance of Fe2+/H2O2 and Fe2+/Persulfate systems in actual pharmaceutical wastewater, and combines EEM, GC-MS, and toxicity testing results to explore the differences in TOC, COD, and NH3-N removal rates, optimal catalyst dosage, applicable pH range, toxicity of effluent after reaction, and pollutant structure between the two systems. The results indicate that the Fe2+/H2O2 system has a higher pollutant removal rate (TOC: 71.9%, COD: 66.9%, NH3-N: 34.1%), but also requires a higher catalyst (Fe2+) concentration (6.0 g/L), and its effluent exhibits characteristic peaks of aromatic proteins. The Fe2+/Persulfate system has a wider pH range (pH ≈ 3-7) and is more advantageous in treating wastewater containing more cyclic organic compounds, but the effluent contains some sulfur-containing compounds. In addition, toxicity tests have shown that the toxicity reduction effect of the Fe2+/Persulfate system is stronger than that of the Fe2+/H2O2 system.

Exploring the mechanism of Icariin in the treatment of depression through BDNF-TrkB pathway based on network pharmacology.

Depression has increasingly become a disease that seriously harms people's mental health around the world. Icariin is the main active component of Epimedii Herba and effective on protecting the central nervous system. The purpose of this study was to explore the mechanism of icariin against depression based on network pharmacology and molecular docking. The potential targets related to icariin and depression were obtained by accessing network databases. The Metascape database was used for the enrichment analysis of GO function and KEGG pathways. A common target-pathway network was constructed using Cytoscape 3.9.0 software. Schrödinger Maestro 12.8 was adopted to evaluate the binding ability of icariin to core targets. Mice were induced by the chronic unpredictable mild stress (CUMS) model, and the prediction results of this study were verified by in vivo experiments. A total of 109 and 3294 targets were identified in icariin and depression, respectively. The common target-pathway network was constructed, and 7 core target genes were obtained. The molecular docking results of the 7 core target genes with icariin showed good affinity. In a CUMS-induced depression model, we found that icariin could effectively improve depression-like behavior of mice, increase the expression of monoamine neurotransmitters 5-hydroxytryptamine, dopamine, and norepinephrine, decrease the secretion of inflammatory factors tumor necrosis factor-α, interleukin-6, and interleukin-1ß, and upregulate the relative expression levels of BDNF, p-TrkB/TrkB, p-Akt/Akt, p-CREB/CREB, MAPK3, MAPK1, Bcl-2, EGFR, and mTOR. The results suggest that icariin has certain antidepressant effects, and may be mediated by the BDNF-TrkB signaling pathway. It provides new ideas for the treatment of depression in the future.

Goat Milk Improves Glucose Metabolism in Type 2 Diabetic Mice and Protects Pancreatic ß-Cell Functions.

SCOPE: Consuming goat milk is known to benefit high-fat diet-fed and streptozocin (STZ)-induced diabetic rats, but the underlying mechanisms are unknown. This study is conducted to investigate the metabolic effects of a goat milk diet (a form of goat milk powder) on glucose homeostasis and pancreatic conditions in a mouse model of Type 2 diabetes mellitus (T2DM) induced by STZ. METHODS AND RESULTS: T2DM mice are fed with a goat-milk-based diet containing 10.3% w/w goat milk powder for 10 weeks for investigating the in vivo effects; a ß-cell line MIN6 cells are used to test the in vitro effects of digested goat milk (DGM). Goat milk diet improves the deleterious effects of STZ on fasting glucose levels and glucose tolerance, accelerates pancreatic structure recovery, and alters blood metabolites in mice. Based on the significant differences observed in metabolites, the key pathways, metabolite regulatory enzymes, metabolite molecular modules, and biochemical reactions are identified as critical integrated pathways. DGM promotes the cell activity, glucose transportation, and AKT activation in cultured STZ-treated MIN6 cells in vitro. CONCLUSIONS: Goat milk diet improves glucose homeostasis and pancreatic conditions of T2DM mice, in association with improved blood metabolite profiles and activation of pancreatic AKT pathway.

CTSC promoted the migration and invasion of glioma cells via activation of STAT3/SERPINA3 axis.

Cathepsin C (CTSC) has been reported to be upregulated in several cancers, however, there are still many missing links about the role of CTSC in glioma. To address this knowledge gap, the present study employed bioinformatics analysis, Transwell assay, RT-qPCR and Western blot assays to investigate the expression level of CTSC in glioma tissues, its relationship with survival period, and its effect on the migration and invasion ability of glioma cells. The findings revealed that CTSC was upregulated in glioma and was associated with poor prognosis. Moreover, CTSC was found to promote cell migration and invasion abilities as well as epithelial-mesenchymal transition (EMT). A further study found that CTSC induced SERPINA3 and STAT3 expression in glioma cells. Additionally, we demonstrated that STAT3 signaling mediated upregulation of SERPINA3 expression by CTSC. In sum, our findings suggest that CTSC activates the STAT3/SERPINA3 axis to promote migration and invasion of glioma cells, which may lead to new potential therapeutic approaches for humans with cancer.

Icariin improves learning and memory function in Aß1-42-induced AD mice through regulation of the BDNF-TrκB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Epimedium brevicornu Maxim. is a traditional medicinal Chinese herb that is enriched with flavonoids, which have remarkably high medicinal value. Icariin (ICA) is a marker compound isolated from the total flavonoids of Epimedium brevicornu Maxim. It has been shown to improve Neurodegenerative disease, therefore, ICA is probably a potential drug for treating AD. MATERIALS AND METHODS: The 6-8-week-old SPF-class male ICR mice were randomly divided into 8 groups for modeling, and then the mice were administered orally with ICA for 21 days. The behavioral experiments were conducted to evaluate if learning and memory behavior were absent in mice, confirming that infusion of Amyloid ß-protein (Aß)1-42 caused significant memory impairment. The morphological changes and damage of neurons in the mice's brains were observed by HE and Nissl staining. The spinous protrusions (dendritic spines) on neuronal dendrites were investigated by Golgi-Cox staining. The molecular mechanism of ICA was examined by Western Blot. The protein docking of ICA and Donepezil with BDNF were analyzed to determine their interaction. RESULTS: The behavioral experimental results showed that in Aß1-42-induced AD mice, the learning and memory abilities were improved after using ICA. At the same time, the low, medium, and high doses of ICA could reduce the content of Aß1-42 in the hippocampus of AD mice, repair neuronal damage, enhance synaptic plasticity, as well as increase the expression of BDNF, TrκB, CREB, Akt, GAP43, PSD95, and SYN proteins in the hippocampus of mice. However, the effect with high doses of ICA is more pronounced. The high-dose administration of ICA has the best therapeutic effect on AD mice. After administering the inhibitor k252a, the therapeutic effect of ICA was reversed. The macromolecular docking results of ICA and BDNF protein demonstrated a strong interaction of -7.8 kcal/mol, which indicates that ICA plays a therapeutic role in AD mice by regulating the BDNF-TrκB signaling pathway. CONCLUSIONS: The results confirm that ICA can repair neuronal damage, enhance synaptic plasticity, as well as ultimately improve learning and memory impairment through the regulation of the BDNF-TrκB signaling pathway.

MLKL deficiency alleviates neuroinflammation and motor deficits in the α-synuclein transgenic mouse model of Parkinson's disease.

Parkinson's disease (PD), one of the most devastating neurodegenerative brain disorders, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN) and deposits of α-synuclein aggregates. Currently, pharmacological interventions for PD remain inadequate. The cell necroptosis executor protein MLKL (Mixed-lineage kinase domain-like) is involved in various diseases, including inflammatory bowel disease and neurodegenerative diseases; however, its precise role in PD remains unclear. Here, we investigated the neuroprotective role of MLKL inhibition or ablation against primary neuronal cells and human iPSC-derived midbrain organoids induced by toxic α-Synuclein preformed fibrils (PFFs). Using a mouse model (Tg-Mlkl-/-) generated by crossbreeding the SNCA A53T synuclein transgenic mice with MLKL knockout (KO)mice, we assessed the impact of MLKL deficiency on the progression of Parkinsonian traits. Our findings demonstrate that Tg-Mlkl-/- mice exhibited a significant improvement in motor symptoms and reduced phosphorylated α-synuclein expression compared to the classic A53T transgenic mice. Furthermore, MLKL deficiency alleviated tyrosine hydroxylase (TH)-positive neuron loss and attenuated neuroinflammation by inhibiting the activation of microglia and astrocytes. Single-cell RNA-seq (scRNA-seq) analysis of the SN of Tg-Mlkl-/- mice revealed a unique cell type-specific transcriptome profile, including downregulated prostaglandin D synthase (PTGDS) expression, indicating reduced microglial cells and dampened neuron death. Thus, MLKL represents a critical therapeutic target for reducing neuroinflammation and preventing motor deficits in PD.

Experimental study of HIFU incomplete ablation on the damage effect and prognosis of rabbit VX2 breast cancer model.

PURPOSE: High-intensity focused ultrasound (HIFU) represents an emerging noninvasive modality for tumor treatment. While biological responses and immunological change associated with incomplete ablation have not been thoroughly investigated. This study aims to evaluate the damage effect of HIFU incomplete ablation via establishing animal model and further explore its possible mechanism to inhibit tumor growth. METHODS: The rabbit VX2 breast cancer model was established and received HIFU treatment with complete ablation (100% tumor volume) and incomplete ablation (about 80% tumor volume) under real-time B-ultrasound monitoring. Histopathological alterations, dynamics of tumor cell apoptosis and proliferation, expression levels of VEGF, MMP-9, IL-2R, TGF-ß1, HSP-70, IL-6, IL-8, and INF-γ, and the presence of circulating tumor cells (CTCs) were evaluated post-HIFU incomplete ablation. RESULTS: For HIFU 80% ablation group, there was an 85.85% reduction in tumor volume 21 days post-intervention. A marked increase in tumor cell apoptosis and a concomitant decrease in proliferation were observed. Notably, distant tumor metastasis rates, CTC counts, and expression levels of VEGF, MMP-9, IL-2R, TGF-ß1, IL-6, and IL-8 were significantly reduced. In contrast, INF-γ and HSP-70 expressions were notably elevated, aligning with findings from the 100% ablation group. CONCLUSIONS: HIFU incomplete ablation, with an 80% tumor ablation rate, induces substantial tumor damage, augments tumor cell apoptosis, and triggers an anti-tumor immune response, curtailing metastasis. These insights may underpin further investigations into the therapeutic implications of HIFU incomplete ablation.

Generation and characterization of chimeric Tembusu viruses containing pre-membrane and envelope genes of Japanese encephalitis virus.

Since its outbreak in 2010, Tembusu virus (TMUV) has spread widely throughout China and Southeast Asia, causing significant economic losses to the poultry industry. In 2018, an attenuated vaccine called FX2010-180P (180P) was licensed for use in China. The 180P vaccine has demonstrated its immunogenicity and safety in mice and ducks. The potential use of 180P as a backbone for flavivirus vaccine development was explored by replacing the pre-membrane (prM) and envelope (E) genes of the 180P vaccine strain with those of Japanese encephalitis virus (JEV). Two chimeric viruses, 180P/JEV-prM-E and 180P/JEV-prM-ES156P with an additional E protein S156P mutation were successfully rescued and characterized. Growth kinetics studies showed that the two chimeric viruses replicated to similar titers as the parental 180P virus in cells. Animal studies also revealed that the virulence and neuroinvasiveness of the 180P/JEV-prM-E chimeric virus was decreased in mice inoculated intracerebrally (i.c.) and intranasally (i.n.), respectively, compared to the wild-type JEV strain. However, the chimeric 180P/JEV-prM-E virus was still more virulent than the parent 180P vaccine in mice. Additionally, the introduction of a single ES156P mutation in the chimeric virus 180P/JEV-prM-ES156P further attenuated the virus, which provided complete protection against challenge with a virulent JEV strain in the mouse model. These results indicated that the FX2010-180P could be used as a promising backbone for flavivirus vaccine development.