Role of sperm morphological parameters in the selection of fertilization methods.

To investigate the role of in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in cases with isolated teratozoospermia, and to provide reference for infertile patients to choose a reasonable insemination program. From January 2018 to December 2022, 433 couples received assisted reproductive assistance in the Department of Reproductive Medicine of our hospital. Among them, 81 patients presented isolated teratozoospermia (other sperm parameters were normal). These underwent IVF/ICSI, and differences in embryological data were compared between groups. 60 patients with moderate teratozoospermia went IVF, 11 needed rescue ICSI (R-ICSI, 18.33%), and 49 developed up to the blastocyst stage. 14 patients with severe teratozoospermia went IVF, 2 needed R-ICSI (14.29%), and 12 developed up to the blastocyst stage. There were no statistically significant differences in the proportion of R-ICSI between the two groups. Embryological outcomes were not significantly different between groups. The present results suggest that patients with moderate and severe teratozoospermia can be effectively treated with IVF, being R-ICSI performed when necessary.

Molecular Interaction and Solubilization Efficiency of Neohesperidin in Ternary Systems with Hydroxypropyl-ß-cyclodextrin and Meglumine.

The solubilization of poorly water-soluble natural bioactive compounds remains a significant challenge. This study aims to design a ternary inclusion system to enhance the solubility of the poorly water-soluble compound Neohesperidin (NH). Soluble ternary cyclodextrin complexations (t-CDs) containing NH, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD), and meglumine (MEG) were prepared and optimized. The optimized t-CDs were further characterized using Scanning Electron Microscopy (SEM), Powder X-ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), and molecular docking (MD) techniques. The results suggested that NH formed was associated with MEG through hydrogen bonds with MEG, and was subsequently incorporated into the hydrophobic cavity of HP-ß-CD, which may be a key factor in improving its solubility. The solubility of NH in water at 37 °C increased significantly from 0.16 mg/mL to 5.81 mg/mL in the optimized t-CDs (NH/MEG/HP-ß-CD).

Haplotype-resolved genome assembly and resequencing provide insights into the origin and breeding of modern rose.

Modern rose (Rosa hybrida) is a recently formed interspecific hybrid and has become one of the most important and widely cultivated ornamentals. Here we report the haplotype-resolved chromosome-scale genome assembly of the tetraploid R. hybrida 'Samantha' ('JACmantha') and a genome variation map of 233 Rosa accessions involving various wild species, and old and modern cultivars. Homologous chromosomes of 'Samantha' exhibit frequent homoeologous exchanges. Population genomic and genomic composition analyses reveal the contributions of wild Rosa species to modern roses and highlight that R. odorata and its derived cultivars are important contributors to modern roses, much like R. chinensis 'Old Blush'. Furthermore, selective sweeps during modern rose breeding associated with major agronomic traits, including continuous and recurrent flowering, double flower, flower senescence and disease resistance, are identified. This study provides insights into the genetic basis of modern rose origin and breeding history, and offers unprecedented genomic resources for rose improvement.

MiR-1307-5p enhances fibroblast transdifferentiation to exacerbate chronic obstructive pulmonary disease through regulating FBXL16/HIF1α axis.

Chronic obstructive pulmonary disease (COPD) is an irreversible and progressive chronic inflammatory lung disease which affects millions of people worldwide. Activated fibroblasts are observed to accumulate in lung of COPD patients and promote COPD progression through aberrant extracellular matrix (ECM) deposition. In this study, we identified that miR-1307-5p expression was significantly increased in lung fibroblasts derived from COPD patients. Mechanistically, we found that upregulation of miR-1307-5p promoted TGF-ß induced lung fibroblast activation and transdifferentiation. We also identified FBXL16 as a direct target for miR-1307-5p mediated myofibroblast activation in COPD. Knockdown of FBXL16 by siRNA prominently increased the expression of myofibroblast markers in MRC-5 fibroblasts after TGF-ß administration. Ectopic expression of FBXL16 in MRC-5 counteracted miR-1307-5p agomir-induced fibroblast transdifferentiation. Furthermore, We found that miR-1307-5p promoted pulmonary fibroblast transdifferentiation through FBXL16 regulated HIF1α degradation. In general, our findings indicate that miR-1307-5p is important for COPD pathogenesis, and may serve as a potential target for COPD treatment.

A microfluidic-based chemiluminescence biosensor for sensitive multiplex detection of exosomal microRNAs based on hybridization chain reaction.

The analysis of microRNAs (miRNAs) in exosomes is of great importance for noninvasive early disease diagnosis. However, current techniques to detect exosomal miRNAs is hampered either by laborious exosome isolation or low abundance of miRNAs in exosomes. Here, we developed a microfluidic chemiluminescence (CL) analysis method for the multiplexed detection of exosomal miR-21 and miR-155. The microfluidic device contained three parts: a snake-shaped channel for fully mixing chemiluminescent reagents, a ship-shaped channel modified with CD63 protein aptamer for capturing exosomes, and another two parallel ship-shaped channels for hybridization chain reaction (HCR) amplification and CL detection. The multiple signal amplification was realized by Y-shaped arrays, HCR amplification, and poly-HRP catalyzed CL reaction. Using this multiple signal amplification method, our microfluidic CL biosensor achieves a limit of detection of miRNAs of 0.49 fM, with a linear range of 1 fM-10 pM, which is better or comparable to previously reported biosensors. What's more, the proposed microfluidic biosensor exhibits great specificity and selectivity to the target miRNA. Moreover, the microfluidic CL strategy exhibited excellent accuracy and could significantly distinguish different cancer subtypes as well as cancer patients and healthy people. These results suggest that this simple, high sensitive, and more accurate analytical strategy by analyzing different types of exosomal miRNAs has the potential applications in cancer diagnosis and stage monitoring.

Effects of long-term continuous cultivation on the structure and function of soil bacterial and fungal communities of Fritillaria Cirrhosa on the Qinghai-Tibetan Plateau.

Fritillaria cirrhosa, an endangered medicinal plant in the Qinghai-Tibet Plateau, is facing resource scarcity. Artificial cultivation has been employed to address this issue, but problems related to continuous cultivation hinder successful transplantation. Imbalanced microbial communities are considered a potential cause, yet the overall changes in the microbial community under continuous cropping systems remain poorly understood. Here, we investigated the effects of varying durations of continuous cropping on the bacterial and fungal communities, as well as enzymatic activities, in the rhizospheric soil of F. cirrhosa. Our findings revealed that continuous cropping of F. cirrhosa resulted in soil acidification, nutrient imbalances, and increased enzyme activity. Specifically, after 10 years of continuous cropping, there was a notable shift in the abundance and diversity (e.g., Chao1 index) of soil bacteria and fungi. Moreover, microbial composition analyses revealed a significant accumulation of harmful microorganisms associated with soil-borne diseases (e.g., Luteimonas, Parastagonospora, Pseudogymnoascus) in successively cropped soils, in contrast to the significant reduction of beneficial microorganisms (e.g., Sphingomonas, Lysobacter, Cladosporium) that promote plant growth and development and protect against diseases such as Fusarium sp.These changes led to decreased connectivity and stability within the soil microbial community. Structural equation modeling and redundancy analysis revealed that alkaline hydrolytic nitrogen and available phosphorus directly influenced soil pH, which was identified as the primary driver of soil microbial community changes and subsequently contributed to soil health deterioration. Overall, our results highlight that soil acidification and imbalanced rhizosphere microbial communities are the primary challenges associated with continuous cropping of F. cirrhosa. These findings establish a theoretical foundation for standardized cultivation practices of F. cirrhosa and the bioremediation of continuously cultivated soils.

UHPLC-QTOF-MS-Based Targeted Metabolomics Provides Novel Insights into the Accumulative Mechanism of Soil Types on the Bioactive Components of Salvia miltiorrhiza.

The root of Salvia miltiorrhiza Bunge (SMB) has been widely used to treat cardiovascular diseases. However, the contents of secondary metabolites in the roots from different production areas are significantly different, and the impact of soil factors on this accumulation remains unclear. Therefore, this study aimed to elucidate the regularity of variation between the active components and soil factors through targeted metabolomics and chemical dosimetry. Soils were collected from five different cities (A, B, C, D, and E) and transplanted into the study area. The results showed that there were significant differences in the soil fertility characteristics and heavy metal pollution levels in different soils. Ten water- and twelve lipid-soluble metabolites were identified in SMBs grown in all soil types. SMBs from D cities exhibited the highest total tanshinone content (p < 0.05). The salvianolic acid B content in SMBs from E cities was the highest (p < 0.05). Interestingly, correlation analysis revealed a significant negative correlation between the accumulation of lipid-soluble and water-soluble metabolites. Double-matrix correlation analysis demonstrated that available potassium (AK) was significantly negatively correlated with salvianolic acid B (r = -0.80, p = 0.0004) and positively correlated with tanshinone IIA (r = 0.66, p = 0.008). Conversely, cadmium (Cd) and cuprum (Cu) were significantly positively and negatively correlated with salvianolic acid B (r = 0.96, p < 0.0001 and r = 0.72, p = 0.0024) and tanshinone IIA (r = 0.40, p = 0.14 and r = 0.73, p = 0.0018), respectively. Mantel's test indicated that AK (r > 0.52, p < 0.001), Cu (r > 0.60, p < 0.005), and Cd (r > 0.31, p < 0.05) were the primary drivers of the differences in the active components of SMBs. These findings provide a theoretical framework for modulating targeted metabolites of SMB through soil factors, with significant implications for the cultivation and quality control of medicinal plants.

Cortex Mori Radicis[Morus Alba L. (Moraceae)] extract alleviates senescence via PI3K/Akt signaling in COPD fibroblasts.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is marked by prolonged exposure to cigarette smoke, which accelerates senescence in lung fibroblasts and contributes to lung fibrosis. Cortex Mori Radicis [Morus albal. (Moraceae)], a traditional Chinese medicinal herb known for its antitussive properties, has emerged as a potential therapeutic agent for COPD. This study aims to elucidate the immunological mechanisms by which Cortex Mori Radicis mitigates COPD progression, utilizing a mouse model and the MRC-5 cell line. METHODS AND RESULTS: COPD mouse models were established through chronic cigarette smoke (CS) exposure, followed by isolation of lung fibroblasts. Senescence markers and inflammatory mediators were assessed in both the isolated cells and the mice. Lung fibroblasts and bleomycin (Bleomycin)-treated MRC-5 cells exhibited elevated expression of senescence markers, including senescence-associated beta-galactosidase activity, p16INK4A, p21, p38 MAPK, and p53, along with increased levels of senescence-associated secretory phenotype (SASP) mRNA, such as IL-6 and IL-8. Treatment with Cortex Mori Radicis significantly attenuated the protein levels of these senescence markers and reduced SASP mRNA expression. Furthermore, integration of transcriptomic data from lung tissues and primary fibroblasts, combined with network pharmacology analysis, indicated that Cortex Mori Radicis inhibits fibroblast senescence via the PI3K/Akt pathway, thereby ameliorating lung pathology in COPD mice. CONCLUSION: Through the application of transcriptomics and network analysis, this study identifies that Cortex Mori Radicis suppresses cigarette smoke-induced senescence in pulmonary tissues and bleomycin (Bleomycin)-exposed MRC-5 cells by targeting the PI3K/Akt signaling pathway. These findings underscore the therapeutic potential of Cortex Mori Radicis as a novel intervention for COPD.

Construction of a pumpless gravity-driven vascularized Skin-on-a-Chip for the study of hepatocytotoxicity in percutaneous exposure to exogenous chemicals.

The utilization of existing Skin-on-a-Chip (SoC) is constrained by the complex structures, the multiplicity of auxiliary devices, and the inability to evaluate exogenous chemicals that are hepatotoxic after percutaneous metabolism. In this study, a gravity-driven SoC without any auxiliary devices was constructed for the hepatocytotoxicity study of exogenous chemicals. The SoC possesses 3 layers of culture chambers, from top to bottom, for human skin equivalent (HSE), Human Umbilical Vein Endothelial Cells (HUVEC) and hepatocytes (HepG2), and the maintenance and expression capacity of the corresponding cells on the SoC were verified by specificity parameters. The reactivity of the SoC to exogenous chemicals was verified by 2-aminofluorene (2-AF). The SoC can realistically simulate the in vivo exposure process of exogenous chemicals that are percutaneously exposed and metabolized into the bloodstream and then to the liver to produce toxicity, and it can achieve the same effects on transcriptome as those of animal tests at lower exposure levels while examining multiple toxicological targets of the skin, vascular endothelial cells, and hepatocytes. Both in terms of species similarity, the principles of reduction, replacement and refinement (3R), or the level of exposure suggest that the present SoC has a degree of replacement for animal models in assessing exogenous chemicals, especially those that are hepatotoxic after percutaneous metabolism.

SOX4 promotes vascular abnormality in glioblastoma and is a novel target to improve drug delivery.

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults with dismal prognosis. Vascular abnormality is a hallmark of GBM, and aggravates diseases progression by increasing hypoxia, inducing life-threaten edema and hindering drug delivery. Nonetheless, the intricate mechanism underlying vascular abnormality remains inadequately understood. Here, we revealed a key role of SOX4 on vascular abnormality in GBM. SOX4 expression was increased in endothelial cells (ECs) from human brain tumors compared with ECs from paired normal brain tissue. Knockdown of SOX4 in mouse brain ECs restrained cell migration and proliferation. Furthermore, in vitro suppression of SOX4 in brain ECs and in vivo conditional knockout of SOX4 in tumor ECs led to the downregulation of genes linked with vascular abnormality. Notably, specific depletion of SOX4 in ECs enhanced drug delivery and sensitive tumor to chemotherapeutic drugs in GBM. Taken together, these results demonstrated that SOX4 is a novel regulator for tumor angiogenesis and vascular abnormality in GBM. Our findings identify SOX4 as a potential vascular therapeutic target to improve drug delivery for GBM treatment.

Chinese mothers' profiles of color-conscious socialization and social dominance orientation: Relations to children's racial attitudes.

OBJECTIVES: This study concerns Chinese mothers' color-conscious socialization and social dominance orientation and how these relate to children's racial attitudes. METHOD: Data were collected from a sample of 155 Chinese children (71 girls) aged 7-11 years and their mothers, from urban regions across China (Shanghai, Jinan, and cities in Jiangsu Province), including observations of mothers' color-conscious practices, self-reported social dominance orientation, and children's attitudes toward light-skinned Chinese, tan-skinned Chinese, and White groups. All children were born in urban areas and from middle-income families. RESULTS: Variable- and person-centered analyses suggested three areas of color-conscious practices, racial appearance, cultural background, and grouping, and revealed heterogeneity in associations between color consciousness and social dominance orientation. Mothers' acknowledgment of shared culture was associated with children's positive attitudes toward their racial ingroup with darker skin tone. CONCLUSIONS: This study emphasizes the importance of a nuanced and contextualized understanding of color-conscious socialization. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Optimization of the extraction process of total steroids from Phillinus gilvus (Schwein.) Pat. by artificial neural network (ANN)-response surface methodology and identification of extract constituents.

Phillinus gilvus (Schwein.) Pat has pharmacological effects such as tonifying the spleen, dispelling dampness, and strengthening the stomach, in which sterol is one of the main compounds of P. gilvus, but there has not been thought you to its extraction and detailed identification of its composition, in the present study, we used artificial neural network (ANN) and response surface methodology (RSM) to optimize the conditions of ultrasonic-assisted extraction, and the parameters of the independent and interaction effects were evaluated. Ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) was used to identify the major components in the purified extract. The results showed that the optimal extraction process conditions were: ultrasonic time 96 min, ultrasonic power 140 W, liquid to material ratio 1:25 g/ml, and ultrasonic temperature 30.7 °C. The compliance rates of the predicted and experimental values for the artificial neural network model and the response surface model were 98.3% and 96.12%, respectively, indicating that both models have the potential to be used for optimizing the extraction process of P. gilvus in industry. A total of 120 compounds and 30 major steroids were identified by comparison with the reference compounds. Among the major steroidal components are these findings will contribute to the isolation and utilization of active ingredients in P. gilvus.

Changes of crystalline structure and physicochemical properties of Pueraria lobata var. thomsonii starch under water deficit.

Crystal type is an important physicochemical property of starch. However, it is currently unclear whether changes in crystal type affect other properties of starch. This study discovered that water deficit resulted in an increase in small starch granules and transparency in Pueraria lobata var. thomsonii, while causing a decrease in amylose content and swelling power. Additionally, the crystal type of P. Thomsonii starch changed from CB-type to CA-type under water deficit, without significantly altering the short-range ordered structure and chain length distribution of starch. This transformation in crystal type led to peak splitting in the DSC heat flow curve of starch, alterations in gelatinization behavior, and an increase in resistant starch content. These changes in crystalline structure and physicochemical properties of starch granules are considered as adaptive strategies employed by P. Thomsonii to cope with water deficit.

Droplet digital molecular beacon-LAMP assay via pico-injection for ultrasensitive detection of pathogens.

A pico-injection-aided digital droplet detection platform is presented that integrates loop-mediated isothermal amplification (LAMP) with molecular beacons (MBs) for the ultrasensitive and quantitative identification of pathogens, leveraging the sequence-specific detection capabilities of MBs. The microfluidic device contained three distinct functional units including droplet generation, pico-injection, and droplet counting. Utilizing a pico-injector, MBs are introduced into each droplet to specifically identify LAMP amplification products, thereby overcoming issues related to temperature incompatibility. Our methodology has been validated through the quantitative detection of Escherichia coli, achieving a detection limit as low as 9 copies/µL in a model plasmid containing the malB gene and 3 CFU/µL in a spiked milk sample. The total analysis time was less than 1.5 h. The sensitivity and robustness of this platform further demonstrated the potential for rapid pathogen detection and diagnosis, particularly when integrated with cutting-edge microfluidic technologies.

Clinical and hematological characteristics of children infected with the omicron variant of SARS-CoV-2: role of the combination of the neutrophil: lymphocyte ratio and eosinophil count in distinguishing severe COVID-19.

Purpose: Investigate the clinical/hematological characteristics of children infected with the Omicron variant of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and identify an effective indicator to distinguish coronavirus disease 2019 (COVID-19) severity in children. Methods: A retrospective study was conducted through electronic medical records from pediatric patients. The demographic, clinical, and routine blood test (RBT) features of children diagnosed by real-time PCR for SARS-CoV-2 were collected. Results: Data of 261 patients were analyzed. The most common abnormality shown by RBTs was increased monocyte count (68%). Children had "mild-moderate" or "severe" forms of COVID-19. Prevalence of abnormal neutrophil count (p = 0.048), eosinophil count (p = 0.006), mean corpuscular volume (p = 0.033), mean platelet volume (p = 0.006), platelet-large cell ratio (p = 0.043), and red blood cell distribution width-standard deviation (p = 0.031) were significantly different in the two types. A combination of the neutrophil: lymphocyte ratio (NLR) and eosinophil count for diagnosing severe COVID-19 presented the largest AUC (0.688, 95% CI = 0.599-0.777; p < 0.001), and the AUC increased with a decrease in age. Conclusions: Combination of the NLR and eosinophil count might be a promising indicator for identifying severe COVID-19 in children at infection onset.

Investigation of mechanisms of shock wave generation by collapse of cavitation bubbles near particles.

The mechanism of generation of shock waves by the collapse of a cavitation bubble near a single particle or dual particles is numerically investigated using OpenFOAM. For the single-particle case, shock waves during bubble inception and jet impacting on the particle surface are revealed in detail. The pressure induced on the particle by the inception shock wave of the bubble decreases with increasing bubble-particle distance, and the pressure is proportional to 1/r1.26 (r being the distance from the center of the shock wave). For the dual particles, the evolution of the neck structure is closely related to the generation mechanism of the shock wave. At extremely close particle-bubble distances, two shock waves propagating in opposite directions are emitted outside and inside the bubble after two necks collide. At long particle-bubble distances, a shock wave is emitted after the neck contracts, and simultaneously the bubble splits into two daughter bubbles. The energy of the shock wave generated by the neck constriction (i.e., the pressure at its generation location) first increases and then decreases with increasing bubble-particle distance. For unequal-sized double particles, the size of the daughter bubble depends on the bubble-particle distance and the particle size. These findings provide new perspectives for understanding the damage sustained by hydro-mechanical components operating in sand-laden water flows.

Jet dynamics of a cavitation bubble near unequal-sized dual particles.

The jet dynamics of a cavitation bubble near unequal-sized dual particles is investigated employing OpenFOAM, and the effects of the jets on the particles are quantitatively analyzed in terms of their pressure impacts. Different from single-particle cases, the necks that evolve between dual particles are closely linked to the formation mechanism of the jets. Based on the simulation results, the jet dynamics can be divided into five scenarios: (1) the contraction of the annular depression produced by the collision of the two necks causes the bubble to split into two daughter bubbles and generates a single jet inside each daughter bubble; (2) the annular depression impacts the particle, leading to the bubble to fracture and producing a single jet inside a daughter bubble; (3) the bubble is split by a single neck constriction and produces a single jet; (4) the bubble is split by a single neck constriction and generates two jets; and (5) the bubble is split by the contraction of two necks and produces four jets together with three daughter bubbles. As the bubble-particle distance or the radius ratio of the dual particles increases, the maximum force on the small particle generated by the bubble decreases.

A computed tomography-based nomogram for neoadjuvant chemotherapy plus immunotherapy response prediction in patients with advanced esophageal squamous cell carcinoma.

Objective: To develop a CT-based nomogram to predict the response of advanced esophageal squamous cell carcinoma (ESCC) to neoadjuvant chemotherapy plus immunotherapy. Methods: In this retrospective study, 158 consecutive patients with advanced ESCC receiving contrast-enhanced CT before neoadjuvant chemotherapy plus immunotherapy were randomized to a training cohort (TC, n = 121) and a validation cohort (VC, n = 37). Response to treatment was assessed with response evaluation criteria in solid tumors. Patients in the TC were divided into the responder (n = 69) and non-responder (n = 52) groups. For the TC, univariate analyses were performed to confirm factors associated with response prediction, and binary analyses were performed to identify independent variables to develop a nomogram. In both the TC and VC, the nomogram performance was assessed by area under the receiver operating characteristic curve (AUC), calibration slope, and decision curve analysis (DCA). Results: In the TC, univariate analysis showed that cT stage, cN stage, gross tumor volume, gross volume of all enlarged lymph nodes, and tumor length were associated with the response (all P < 0.05). Binary analysis demonstrated that cT stage, cN stage, and tumor length were independent predictors. The independent factors were imported into the R software to construct a nomogram, showing the discriminatory ability with an AUC of 0.813 (95% confidence interval: 0.735-0.890), and the calibration curve and DCA showed that the predictive ability of the nomogram was in good agreement with the actual observation. Conclusion: This study provides an accurate nomogram to predict the response of advanced ESCC to neoadjuvant chemotherapy plus immunotherapy.

Changes of Active Substances in Ganoderma lucidum during Different Growth Periods and Analysis of Their Molecular Mechanism.

Ganoderma lucidum, renowned as an essential edible and medicinal mushroom in China, remains shrouded in limited understanding concerning the intrinsic mechanisms governing the accumulation of active components and potential protein expression across its diverse developmental stages. Accordingly, this study employed a meticulous integration of metabolomics and proteomics techniques to scrutinize the dynamic alterations in metabolite accumulation and protein expression in G. lucidum throughout its growth phases. The metabolomics analysis unveiled elevated levels of triterpenoids, steroids, and polyphenolic compounds during the budding stage (BS) of mushroom growth, with prominent compounds including Diplazium and Ganoderenic acids E, H, and I, alongside key steroids such as cholesterol and 4,4-dimethyl-5alpha-cholesta-8,14,24-trien-3beta-ol. Additionally, nutrients such as polysaccharides, flavonoids, and purines exhibited heightened presence during the maturation stage (FS) of ascospores. Proteomic scrutiny demonstrated the modulation of triterpenoid synthesis by the CYP450, HMGR, HMGS, and ERG protein families, all exhibiting a decline as G. lucidum progressed, except for the ARE family, which displayed an upward trajectory. Therefore, BS is recommended as the best harvesting period for G. lucidum. This investigation contributes novel insights into the holistic exploitation of G. lucidum.

Bispecific antibodies targeting two glycoproteins on SFTSV exhibit synergistic neutralization and protection in a mouse model.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high fatality rate of up to 30% caused by SFTS virus (SFTSV). However, no specific vaccine or antiviral therapy has been approved for clinical use. To develop an effective treatment, we isolated a panel of human monoclonal antibodies (mAbs). SF5 and SF83 are two neutralizing mAbs that recognize two viral glycoproteins (Gn and Gc), respectively. We found that their epitopes are closely located, and we then engineered them as several bispecific antibodies (bsAbs). Neutralization and animal experiments indicated that bsAbs display more potent protective effects than the parental mAbs, and the cryoelectron microscopy structure of a bsAb3 Fab-Gn-Gc complex elucidated the mechanism of protection. In vivo virus passage in the presence of antibodies indicated that two bsAbs resulted in less selective pressure and could efficiently bind to all single parental mAb-escape mutants. Furthermore, epitope analysis of the protective mAbs against SFTSV and RVFV indicated that they are all located on the Gn subdomain I, where may be the hot spots in the phleboviruses. Collectively, these data provide potential therapeutic agents and molecular basis for the rational design of vaccines against SFTSV infection.