Interaction between the SFTSV envelope glycoprotein Gn and STING inhibits the formation of the STING-TBK1 complex and suppresses the NF-κB signaling pathway.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne bunyavirus with high pathogenicity. There has been a gradual increase in the number of reported cases in recent years, with high morbidity and mortality rates. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway plays an important role in the innate immune defense activated by viral infection; however, the role of the cGAS-STING signaling pathway during SFTSV infection is still unclear. In this study, we investigated the relationship between SFTSV infection and cGAS-STING signaling. We found that SFTSV infection caused the release of mitochondrial DNA into the cytoplasm and inhibits downstream innate immune signaling pathways by activating the cytoplasmic DNA receptor cGAS. We found that the SFTSV envelope glycoprotein Gn was a potent inhibitor of the cGAS-STING pathway and blocked the nuclear accumulation of interferon regulatory factor 3 and p65 to inhibit downstream innate immune signaling. Gn of SFTSV interacted with STING to inhibit STING dimerization and inhibited K27-ubiquitin modification of STING to disrupt the assembly of the STING-TANK-binding kinase 1 complex and downstream signaling. In addition, Gn was found to be involved in inducing STING degradation, further inhibiting the downstream immune response. In conclusion, this study identified the important role of the glycoprotein Gn in the antiviral innate immune response and revealed a novel mechanism of immune escape for SFTSV. Moreover, this study increases the understanding of the pathogenic mechanism of SFTSV and provides new insights for further treatment of SFTS. IMPORTANCE: Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly discovered virus associated with severe hemorrhagic fever in humans. However, the role of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway during SFTSV infection is still unclear. We found that SFTSV infection inhibits downstream innate immune signaling pathways by activating the cytoplasmic DNA receptor cGAS. In addition, SFTSV Gn blocked the nuclear accumulation of interferon regulatory factor 3 and p65 to inhibit downstream innate immune signaling. Moreover, we determined that Gn of SFTSV inhibited K27-ubiquitin modification of STING to disrupt the assembly of the STING-TANK-binding kinase 1 complex and downstream signaling. We found that the SFTSV envelope glycoprotein Gn is a potent inhibitor of the cGAS-STING pathway. In conclusion, this study highlights the crucial function of the glycoprotein Gn in the antiviral innate immune response and reveals a new method of immune escape of SFTSV.

Dabie bandavirus Nonstructural Protein Interacts with Actin to Induce F-Actin Rearrangement and Inhibit Viral Adsorption and Entry.

Dabie bandavirus (DBV) is an emerging Bandavirus that causes multiorgan failure with a high fatality rate in humans. While many viruses can manipulate the actin cytoskeleton to facilitate viral growth, the regulation pattern of the actin cytoskeleton and the molecular mechanisms involved in DBV entry into the host cells remain unclear. In this study, we demonstrate that expression of nonstructural protein (NSs) or infection with DBV induces actin rearrangement, which presents a point-like distribution, and this destruction is dependent on inclusion bodies (IBs). Further experiments showed that NSs inhibits viral adsorption by destroying the filopodium structure. In addition, NSs also compromised the viral entry by inhibiting clathrin aggregation on the cell surface and capturing clathrin into IBs. Furthermore, NSs induced clathrin light chain B (CLTB) degradation through the K48-linked ubiquitin proteasome pathway, which could negatively regulate clathrin-mediated endocytosis, inhibiting the viral entry. Finally, we confirmed that this NSs-induced antiviral mechanism is broadly applicable to other viruses, such as enterovirus 71 (EV71) and influenza virus, A/PR8/34 (PR8), which use the same clathrin-mediated endocytosis to enter host cells. In conclusion, our study provides new insights into the role of NSs in inhibiting endocytosis and a novel strategy for treating DBV infections. IMPORTANCEDabie bandavirus (DBV), a member of the Phenuiviridae family, is a newly emerging tick-borne pathogen that causes multifunctional organ failure and even death in humans. The actin cytoskeleton is involved in various crucial cellular processes and plays an important role in viral life activities. However, the relationship between DBV infection and the actin cytoskeleton has not been described in detail. Here, we show for the first time the interaction between NSs and actin to induce actin rearrangement, which inhibits the viral adsorption and entry. We also identify a key mechanism underlying NSs-induced entry inhibition in which NSs prevents clathrin aggregation on the cell surface by hijacking clathrin into the inclusion body and induces CLTB degradation through the K48-linked ubiquitination modification. This paper is the first to reveal the antiviral mechanism of NSs and provides a theoretical basis for the search for new antiviral targets.

CRISPR/Cas9 nanoeditor of double knockout large fragments of E6 and E7 oncogenes for reversing drugs resistance in cervical cancer.

Drug resistance of tumor cells is always a headache problem in clinical treatment. In order to combat chemotherapy-resistance in cervical cancer and improve treatment effect, we design a CRISPR/Cas9 nanoeditor to knock out two key oncogenes E6 and E7 that lead to drug tolerance. Meanwhile, the deletion of these two oncogenes can effectively reactivate p53 and pRB signaling pathways that inhibit the growth of tumor cells. Our results demonstrated the nanoeditor could simultaneously delete two oncogenes, and the size of DNA fragments knocked out reaches an unprecedented 563 bp. After the preparation of cationic liposomes combined with chemotherapy drug docetaxel (DOC), this nanosystem can significantly inhibit the drug tolerance of cancer cells and improve the therapeutic effect of cervical cancer. Therefore, this study provides a promising strategy for the treatment of cervical cancer by combining chemotherapy and double-target gene therapy. This strategy can also be applied in other disease models to customize personalized anti-tumor strategies by simply changing chemotherapy drugs and targeted genes.

Inhalable nanovaccine with biomimetic coronavirus structure to trigger mucosal immunity of respiratory tract against COVID-19.

The COVID-19 pandemic caused by SARS-CoV-2 seriously threatens global public health. It has previously been confirmed that SARS-CoV-2 is mainly transmitted between people through "respiratory droplets". Therefore, the respiratory tract mucosa is the first barrier to prevent virus invasion. It is very important to stimulate mucosal immunity to protect the body from respiratory virus infection. Inspired by this, we designed a bionic-virus nanovaccine, which can induce mucosal immunity by nasal delivery to prevent virus infection from respiratory tract. The nanovaccine that mimic virosome is composed of poly(I:C) mimicking viral genetic material as immune adjuvant, biomimetic pulmonary surfactant (bio-PS) liposomes as capsid structure of virus and the receptor binding domains (RBDs) of SARS-CoV-2 as "spike" to completely simulate the structure of the coronavirus. The nanovaccine can be administered by inhaling to imitate the process of SARS-CoV-2 infection through the respiratory tract. Our results demonstrated that the inhalable nanovaccine with bionic virus-like structure has a stronger mucosal protective effect than routine muscle and subcutaneous inoculation. In particular, high titer of secretory immunoglobulin A (sIgA) was detected in respiratory secretions, which effectively neutralize the virus and prevent it from entering the body through the respiratory tract. Through imitating the structure and route of infection, this inhalable nanovaccine strategy might inspire a new approach to the precaution of respiratory viruses.

Is extremely low frequency pulsed electromagnetic fields applicable to gliomas? A literature review of the underlying mechanisms and application of extremely low frequency pulsed electromagnetic fields.

Gliomas refer to a group of complicated human brain tumors with a low 5-year survival rate and limited therapeutic options. Extremely low-frequency pulsed electromagnetic field (ELF-PEMF) is a specific magnetic field featuring almost no side effects. However, the application of ELF-PEMF in the treatment of gliomas is rare. This review summarizes five significant underlying mechanisms including calcium ions, autophagy, apoptosis, angiogenesis, and reactive oxygen species, and applications of ELF-PEMF in glioma treatment from a clinical practice perspective. In addition, the prospects of ELF-PEMF in combination with conventional therapy for the treatment of gliomas are reviewed. This review benefits any specialists, especially oncologists, interested in this new therapy because it can help treat patients with gliomas properly.

Enterovirus D68 VP3 Targets the Interferon Regulatory Factor 7 To Inhibit Type I Interferon Response.

Enterovirus D68 (EV-D68) is a globally emerging pathogen causing severe respiratory illnesses mainly in children. The protease from EV-D68 could impair type I interferon (IFN-I) production. However, the role of the EV-D68 structural protein in antagonizing host antiviral responses remains largely unknown. We showed that the EV-D68 structural protein VP3 interacted with IFN regulatory factor 7 (IRF7), and this interaction suppressed the phosphorylation and nuclear translocation of IRF7 and then repressed the transcription of IFN. Furthermore, VP3 inhibited the TNF receptor associated factor 6 (TRAF6)-induced ubiquitination of IRF7 by competitive interaction with IRF7. IRF7Δ305-503 showed much weaker interaction ability to VP3, and VP3Δ41-50 performed weaker interaction ability with IRF7. The VP3 from enterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16) was also found to interact with the IRF7 protein. These results indicate that the enterovirus structural protein VP3 plays a pivotal role in subverting host innate immune responses and may be a potential target for antiviral drug research. IMPORTANCE EV-D68 is a globally emerging pathogen that causes severe respiratory illnesses. Here, we report that EV-D68 inhibits innate immune responses by targeting IRF7. Further investigations revealed that the structural protein VP3 inhibited the TRAF6-induced ubiquitination of IRF7 by competitive interaction with IRF7. These results indicate that the control of IRF7 by VP3 may be a mechanism by which EV-D68 represses IFN-I production.

Dual Detection of Hemagglutinin Proteins of H5N1 and H1N1 Influenza Viruses Based on FRET Combined With DNase I.

Influenza A viruses (IAV) are classified based on their surface proteins hemagglutinin (HA) and neuraminidase (NA). Both pandemic H1N1 (pH1N1) and highly pathogenic avian influenza (HPAI) H5N1 viruses pose a significant threat to public health. Effective methods to simultaneously distinguish H1N1 and H5N1 are thus of great clinical value. In this study, a protocol for detection of HA proteins of both H1N1 and H5N1 was established. Specifically, we designed an aptasensor for HA using fluorescence resonance energy transfer (FRET) strategy combined with DNase I-assisted cyclic enzymatic signal amplification. HA aptamers of H1N1 and H5N1 IAVs labeled with various fluorescent dyes were used as probes. Graphene oxide (GO) acted as a FRET acceptor for quenching the fluorescence signal and protected aptamers from DNase I cleavage. The fluorescence signal was recovered owing to aptamer release from GO with HA protein. DNase I-digested free aptamers and HA proteins were able to further interact with more fluorescent aptamer probes, resulting in increased signal amplification. The limits of detection (LOD) of H5N1 HA and H1N1 HA were 0.73 and 0.43 ng/ml, respectively, which were 19 and 27 times higher than LOD values obtained with the DNase I-free system. The recovery rate of HA protein in human serum samples ranged from 88.23 to 117.86%, supporting the accuracy and stability of this method in a complex detection environment. Our rapid, sensitive, and cost-effective novel approach could be expanded to other subtypes of IAVs other than H1N1 and H5N1.

CRISPR/Cas12a Technology Combined With RPA for Rapid and Portable SFTSV Detection.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a new tick-borne pathogen that can cause severe hemorrhagic fever. Fever with thrombocytopenia syndrome caused by SFTSV is a new infectious disease that has posed a great threat to public health. Therefore, a fast, sensitive, low-cost, and field-deployable detection method for diagnosing SFTSV is essential for virus surveillance and control. In this study, we developed a rapid, highly sensitive, instrument-flexible SFTSV detection method that utilizes recombinase polymerase amplification and the CRISPR/Cas12a system. We found that three copies of the L gene from the SFTSV genome per reaction were enough to ensure stable detection within 40 min. The assay clearly showed no cross-reactivity with other RNA viruses. Additionally, our method demonstrated 100% agreement with Q-PCR detection results for SFTSV in 46 clinical samples. We simplified the requirements for on-site detection instruments by combining the CRISPR/Cas12a tool and immunochromatographic strips to create a system that can reliably detect one copy/µl sample of the L gene, which showed extremely high sensitivity and specificity for detecting the virus. Taken together, these findings indicate that the new SFTSV detection method is a powerful and effective tool for on-site detection, which can contribute to diagnosing SFTSV quickly and sensitively.

Upconversion Fluorescence Resonance Energy Transfer Aptasensors for H5N1 Influenza Virus Detection.

Influenza A virus (IAV) poses a significant threat to human health, which calls for the development of efficient detection methods. The present study constructed a fluorescence resonance energy transfer (FRET) system based on novel fluorescent probes and graphene oxide (GO) for detecting H5N1 IAV hemagglutinin (HA). Here, we synthesized small (sub-20 nm) sandwich-structured upconversion nanoparticles (UCNPs) (SWUCNPs for short) with a high energy transfer efficiency, which allows for controlling the emitter in a thin shell. The π-π stacking interaction between the aptamer and GO shortens the distance between the fluorescent probe and the receptor, thereby realizing fluorescence resonance energy transfer (FRET). When HA is present, the aptamer enables changes in their conformations and move away from GO surface. Fluorescence signals display a linear relationship between HA quantitation in the range of 0.1-15 ng mL-1 and a limit of detection (LOD) of 60.9 pg mL-1. The aptasensor was also applicable in human serum samples with a linear range from 0.2 to 12 ng mL-1 and a limit of detection of 114.7 pg mL-1. This strategy suggested the promising prospect of the aptasensor in clinical applications because of the excellent sensing performance and sensitivity. This strategy may be promising for vitro diagnostics and provides new insights into the functioning of the SWUCNPs system.

Radiomic signatures based on multiparametric MR images for predicting Ki-67 index expression in medulloblastoma.

BACKGROUND: Medulloblastoma (MB) is a common central nervous system tumor in children with extensive heterogeneity and different prognoses. This study aimed to classify the Ki-67 index in MB with radiomic characteristics based on multi-parametric magnetic resonance imaging to guide treatment and assess the prognosis of patients. METHODS: Three sequences of T1W, CE-T1W, and T2W were used as test data. Two experienced radiologists manually segmented the tumors according to T2W images from 90 patients. The patients were divided into training and test sets at a ratio of 7:3, and 833 dimensional image features were extracted for each patient. Five models were trained using the feature set selected in three ways. Finally, the area under the curve (AUC) and accuracy (ACC) were used on the test set to evaluate the performance of the different models. RESULTS: A random forest (RF) model combining three sequence features achieved the best performance (ACC: 0.771, 95% CI: 0.727 to 0.816; AUC: 0.697, 95% CI: 0.614 to 0.78). The voting model that combined a RF and a support vector machine (SVM) had higher performance than the other models (ACC: 0.796, 95% CI: 0.76 to 0.833; AUC: 0.689, 95% CI: 0.615 to 0.763). The best prediction model that used only one sequence feature was voting in the T2W sequence (ACC: 0.736, 95% CI: 0.705 to 0.766; AUC: 0.636, 95% CI: 0.585 to 0.688). The ensemble model was better than the single training model, and a multi-sequence combination was better than a single sequence prediction. The multiple feature selection methods were better than a combination of the two methods. CONCLUSIONS: A model obtained by machine learning could help doctors predict the Ki-67 values of patients more efficiently to make targeted judgments for subsequent treatments.

Bio-Inorganic Hybrid Nongenetically Modified Viruses as an Immune Agonist for Systemic Elimination of Cancer Cells.

Microbial-based cancer therapy is nowadays considered as an interesting approach, especially with viruses which are attracting more attention owing to their simple structure and nanoscale. However, because of the need for cumbersome genetic modification and poor biosafety, its application is seriously limited. Here, nonpathogenic natural Sendai viruses (SEVs) are used as an alternative immune agonist after being mineralized by calcium ions. Both in vitro and in vivo studies indicated that virus-inorganic hybrids can effectively excite antigen-presenting cells (APCs). Then, the tumor antigens were released in large amounts by photothermal damage. Meanwhile, these released antigens were presented to lymph nodes to mature antitumor T lymphocytes via the peritumoral APCs previously recruited by the SEV. Our results demonstrated that even after administration at one point, the nanohybrids could still effectively stimulate systemic antitumor immune response to suppress the potential cancer metastatic spread. The bio-inorganic hybrid nongenetically modified virus-inorganic nanocomposites might serve as an alternative strategy for synergistic immune therapy.

Enzyme-Antibody-Modified Gold Nanoparticle Probes for the Ultrasensitive Detection of Nucleocapsid Protein in SFTSV.

As humans and climate change continue to alter the landscape, novel disease risk scenarios have emerged. Sever fever with thrombocytopenia syndrome (SFTS), an emerging tick-borne infectious disease first discovered in rural areas of central China in 2009, is caused by a novel bunyavirus (SFTSV). The potential for SFTS to spread to other countries in combination with its high fatality rate, possible human-to-human transmission, and extensive prevalence among residents and domesticated animals in endemic regions make the disease a severe threat to public health. Because of the lack of preventive vaccines or useful antiviral drugs, diagnosis of SFTS is the key to prevention and control of the SFTSV infection. The development of serological detection methods will greatly improve our understanding of SFTSV ecology and host tropism. We describe a highly sensitive protein detection method based on gold nanoparticles (AuNPs) and enzyme-linked immunosorbent assay (ELISA)-AuNP-based ELISA. The optical sensitivity enhancement of this method is due to the high loading efficiency of AuNPs to McAb. This enhances the concentration of the HRP enzyme in each immune sandwich structure. The detection limit of this method to the nucleocapsid protein (NP) of SFTSV was 0.9 pg mL-1 with good specificity and reproducibility. The sensitivity of AuNP-based ELISA was higher than that of traditional ELISA and was comparable to real-time quantitative polymerase chain reaction (qRT-PCR). The probes are stable for 120 days at 4 °C. This can be applied to diagnosis and hopefully can be developed into a commercial ELISA kit. The ultrasensitive detection of SFTSV will increase our understanding of the distribution and spread of SFTSV, thus helping to monitor the changes in tick-borne pathogen SFTSV risk in the environment.

Triglyceride metabolism and angiopoietin-like proteins in lipoprotein lipase regulation.

Hypertriglyceridemia is a risk factor for a series of diseases, such as cardiovascular disease (CVD), diabetes and nonalcoholic fatty liver disease (NAFLD). Angiopoietin-like proteins (ANGPTLs) family, especially ANGPTL3, ANGPTL4 and ANGPTL8, which regulate lipoprotein lipase (LPL) activity, play pivotal roles in triglyceride (TG) metabolism and related diseases/complications. There are many transcriptional and post-transcriptional factors that participate in physiological and pathological regulation of ANGPTLs to affect triglyceride metabolism. This review is intended to focus on the similarity and difference in the expression, structural features, regulation profile of the three ANGPTLs and inhibitory models for LPL. Description of the regulatory factors of ANGPTLs and the properties in regulating the lipid metabolism involved in the underlying mechanisms in pathological effects on diseases will provide potential therapeutic approaches for the treatment of dyslipidemia related diseases.

Optimization of Process Parameters and Kinetic Model of Enzymatic Extraction of Polyphenols from Lonicerae Flos.

OBJECTIVE: To optimize and verify the cellulase extraction of polyphenols from honeysuckle and provide a reference for enzymatic extracting polyphenols from honeysuckle. MATERIALS AND METHODS: The uniform design was used According to Fick's first law and kinetic model, fitting analysis of the dynamic process of enzymatic extracting polyphenols was conducted. RESULTS: The optimum enzymatic extraction parameters for polyphenols from honeysuckle are found to be 80% (v/v) of alcohol, 35:1 (mL/g) of liquid-solid ratio, 80°C of extraction temperature, 8.5 of pH, 6.0 mg of enzyme levels, and 130 min of extraction time. Under the optimal conditions, the extraction rate of polyphenols was 3.03%. The kinetic experiments indicated kinetic equation had a good linear relationship with t even under the conditions of different levels of enzyme and temperature, which means fitting curve tallies well with the experimental values. CONCLUSION: The results of quantification showed that the results provide a reference for enzymatic extracting polyphenols from honeysuckle. SUMMARY: Lonicerae flos (Lonicera japonica Thunb.) is a material of traditional Chinese medicine and healthy drinks, of which active compounds mainly is polyphenols. At present, plant polyphenols are the hotspots centents of food, cosmetic and medicine, because it has strong bioactivity. Several traditional methods are available for the extraction of plant polyphenols including impregnation, solvent extraction, ultrasonic extraction, hot-water extraction, alkaline dilute alcohol or alkaline water extraction, microwave extraction and Supercritical CO2 extraction. But now, an increasing number of research on using cellulase to extract active ingredients from plants. Enzymatic method is widely used for enzyme have excellent properties of high reaction efficiency and specificity, moderate reaction conditions, shorter extraction time and easier to control, less damage to the active ingredient. At present, the enzymatic extraction of polyphenols from honeysuckle and dynamic had not been reported. In this study, using cellulase to extract polyphenols from honeysuckle is first applied. Moreover, uniform design was used to optimize process and kinetic model of extraction was established to analyze the characteristics of enzymatic extraction, in order to improve the yield of polyphenols from honeysuckle and make maximum use of Lonicerae flos, which provide references for industrial production.