- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Super-resolution microscopy reveals significant impact of M2e-specific monoclonal antibodies on influenza A virus filament formation at the host cell surface
摘要： Influenza A virions are highly pleomorphic, exhibiting either spherical or filamentous morphology. The influenza A virus strain A/Udorn/72 (H3N2) produces copious amounts of long filaments on the surface of infected cells where matrix protein 1 (M1) and 2 (M2) play a key role in virus filament formation. Previously, it was shown that an anti-M2 ectodomain (M2e) antibody could inhibit A/Udorn/72 virus filament formation. However, the study of these structures is limited by their small size and complex structure. Here, we show that M2e-specific IgG1 and IgG2a mouse monoclonal antibodies can reduce influenza A/Udorn/72 virus plaque growth and infectivity in vitro. Using Immuno-staining combined with super-resolution microscopy that allows us to study structures beyond the diffraction limit, we report that M2 is localized at the base of viral filaments that emerge from the membrane of infected cells. Filament formation was inhibited by treatment of A/Udorn/72 infected cells with M2e-specific IgG2a and IgG1 monoclonal antibodies and resulted in fragmentation of pre-existing filaments. We conclude that M2e-specific IgGs can reduce filamentous influenza A virus replication in vitro and suggest that in vitro inhibition of A/Udorn/72 virus replication by M2e-specific antibodies correlates with the inhibition of filament formation on the surface of infected cells.
关键词： influenza A virus,viral replication,super-resolution microscopy,filament formation,M2e-specific monoclonal antibodies
更新于2025-11-21 11:08:12
-
Amplified visual immunosensor integrated with nanozyme for ultrasensitive detection of avian influenza virus
摘要： Nanomaterial-based artificial enzymes or nanozymes exhibit superior properties such as stability, cost effectiveness and ease of preparation in comparison to conventional enzymes. However, the lower catalytic activity of nanozymes limits their sensitivity and thereby practical applications in the bioanalytical field. To overcome this drawback, herein we propose a very simple but highly sensitive, specific and low-cost dual enhanced colorimetric immunoassay for avian influenza A (H5N1) virus. 3,3′,5,5′- Tetramethylbenzidine (TMBZ) was used as a reducing agent to produce gold nanoparticles (Au NPs) with blue colored solution from a viral target-specific antibody-gold ion mixture at first step. The developed blue color from the sensing design was further amplified through catalytic activity of Au NPs in presence of TMBZ–hydrogen peroxide (H2O2) solution in second step. Hence, the developed dual enhanced colorimetric immunosensor enables the detection of avian influenza virus A (H5N1) with a limit of detection (LOD) of 1.11 pg/mL. Our results confirmed that the developed assay has superior sensitivity than the conventional ELISA method, plasmonic-based bioassay and commercial flu diagnostic kits. Proposed sensing method further showed its capability to detect viruses, avian influenza A (H4N6) and A (H9N2) virus, in blood samples with limit of detection of 0.0269 HAU and 0.0331 HAU respectively.
关键词： Peroxidase mimic,Dual color enhancement,Gold nanoparticles,Avian influenza virus detection
更新于2025-11-14 17:04:02
-
Rapid preimplantation genetic screening (PGS) using a handheld, nanopore-based, DNA sequencer
摘要： Background/aims: A birth dose of hepatitis B immunoglobulin (HBIG), in combination with hepatitis B vaccine (HepB), is recommended for infants born to hepatitis B surface antigen (HBsAg)-positive mothers. However, the optimal dosage of HBIG remains to be resolved. This prospective cohort study aimed to compare the efficacy of two dosages of HBIG combined with HepB to prevent mother-to-child transmission (MTCT) of HBV. Methods: From 2009 to 2011, we prospectively enrolled mother-infant pairs with positive maternal HBsAg in China. Infants were assigned to receive one dose of 100 IU or 200 IU HBIG within 12 h of birth according to maternal numbering, followed by completion of the 3-dose 10 μg HepB series. At 7 months, post-vaccination serologic testing (PVST) was performed in 545 and 632 infants in 100 IU and 200 IU HBIG groups, respectively, among whom, 451 and 529 were followed up to 12 months. Results: Maternal and birth characteristics were comparable between infants in 100 IU and 200 IU HBIG groups. At 7 months, the rates of perinatal infection were 1.5% (8/545) and 1.9% (12/632) in 100 IU and 200 IU HBIG groups, respectively (p = .568). One non-responder infant in 200 IU HBIG group became newly infected at 12 months. The antibody to hepatitis B surface antigen (anti-HBs) positive rates were 98.5% (529/537) and 98.2% (609/620) in 100 IU and 200 IU HBIG groups at 7 months, respectively (p = .704), and the corresponding figures were 98.2% (431/439) and 97.1% (496/511) at 12 months (p = .266). The anti-HBs geometric mean concentrations were comparable between two groups at 7 months (707.95 mIU/mL vs. 602.56 mIU/mL, p = .062) and 12 months (245.47 mIU/mL vs. 229.09 mIU/mL, p = .407). Conclusions: One birth dose of 100 IU HBIG, combined with the HepB series, might be enough for preventing MTCT of HBV in infants born to HBsAg-positive mothers.
关键词： Antibody to hepatitis B surface antigen,Mother-to-child transmission,Hepatitis B virus,Hepatitis B immunoglobulin,Hepatitis B vaccine
更新于2025-09-23 15:23:52
-
Fully Packaged Portable Thin Film Biosensor for the Direct Detection of Highly Pathogenic Viruses from On-Site Samples
摘要： The thin film transistor (TFT) is a promising biosensor system with great sensitivity, label-free detection, and a quick response time. However, even though the TFT sensor has such advantageous characteristics, the disadvantages hamper the TFT sensor's application in the clinical field. The TFT is susceptible to light, noise, vibration, and limited usage, and this significantly limits its on-site potential as a practical biosensor. Herein, we developed a fully packaged, portable TFT electrochemical biosensor into a chip form, providing both portability through minimizing the laboratory equipment size and multiple safe usages by protecting the semiconductor sensor. Additionally, a safe environment that serves as a miniature probe station minimizes the previously mentioned disadvantages, while providing the means to properly link the TFT biosensor with a portable analyzer. The biosensor was taken into a biosafety level 3 (BSL-3) laboratory setting to analyze highly pathogenic avian influenza virus (HPAIV) samples. This virus quickly accumulates within a host, and therefore, early stage detection is critical to deterring the further spread of the deadly disease to other areas. However, current on-site methods have poor limits of detection (105?106 EID50/mL), and because the virus has low concentration in its early stages, it cannot be detected easily. We have compared the sample measurements from our device with virus concentration data obtained from a RT-PCR (virus range: 100?104 EID50/mL) and have identified an increasing voltage signal which corresponds to increasing virus concentration.
关键词： avian influenza virus,label-free detection,portable biosensor,chip sensor,rapid detection
更新于2025-09-23 15:23:52
-
Digital LAMP on a Commercial Membrane
摘要： In this work, we report digital loop-mediated isothermal amplification (LAMP) or reverse-transcription LAMP (RT-LAMP) on a commercial membrane, without the need for complex chip fabrication or use of specialized equipment. Due to the pore size distribution, the theoretical error for digital LAMP on these membranes was analyzed, using a combination of Random Distribution Model and Multi-volume Theory. A facile peel-off process was developed for effective droplets formation on the commercial track-etched polycarbonate (PCTE) membrane. Each pore functions as an individual nanoreactor for single DNA amplification. Absolute quantification of bacteria genomic DNA was realized with a dynamic range from 11 to 1.1 × 10^5 copies/μL. One-step digital RT-LAMP was also successfully performed on the membrane for the quantification of MS2 virus in wastewater. With the introduction of new probes, the positive pores can be easily distinguished from negative ones with 100 times difference in fluorescence intensities. Finally, the cost of a disposable membrane is less than $0.1/piece, which, to the best of our knowledge, is the most inexpensive way to perform digital LAMP. The membrane system offers opportunities for point-of-care users or common laboratories to perform digital quantification, single cell analysis, or other bioassays in an inexpensive, flexible and simplified way.
关键词： Digital LAMP,RT-LAMP,PCR,Droplets,Virus,Microfluidic,Membrane,Nucleic acid
更新于2025-09-23 15:23:52
-
Smartphone-Based Fluorescent Lateral Flow Immunoassay Platform for Highly Sensitive Point-of-Care Detection of Zika Virus Nonstructural Protein 1
摘要： Simple, inexpensive, and rapid diagnostic tests in low-resource settings with limited laboratory equipment and technical expertise are instrumental in reducing morbidity and mortality from epidemic infectious diseases. We developed a smartphone-based fluorescent lateral flow immunoassay (LFIA) platform for the highly sensitive point-of-care detection of Zika virus nonstructural protein 1 (ZIKV NS1). An attachment was designed and 3D-printed to integrate the smartphone with external optical and electrical components, enabling the miniaturization of the instrument and reduction in cost and complexity. Quantum dot microspheres were utilized as probes in fluorescent LFIA because of their extremely bright fluorescence signal. This approach can achieve quantitative point-of-care detection of ZIKV NS1 within 20 min. Limits of detection (LODs) in buffer and serum were 0.045 and 0.15 ng mL-1, respectively. Despite the high structural similarity, a high-level Dengue virus NS1 as interferent showed limited cross-reactivity. Furthermore, this assay was successfully applied to detecte ZIKV NS1 and virions spiked in complex biological samples, indicating its practical application capability. Given its low cost, compact size, and excellent analytical performance, the proposed smartphone-based fluorescent LFIA platform holds considerable potential in rapid and accurate point-of-care detection of ZIKV NS1 and provides new insight into the design and application of molecular diagnostic methods in low-resource settings.
关键词： Quantum dot microsphere,Smartphone,Lateral flow immunoassay,Zika virus nonstructural protein 1,Point-of-care
更新于2025-09-23 15:23:52
-
Ultrasensitive detection of avian influenza A (H7N9) virus using surface-enhanced Raman scattering-based lateral flow immunoassay strips
摘要： The development of biosensors that are portable, low-cost, and quantitative has long been sought for rapid, on-site, and timely detection of avian influenza virus (AIV). In this study, an antibody-based Raman lateral flow immunoassay strip was developed to detect AIV H7N9. This LFIA strip used a novel core-shell structure material, AuAg4(cid:3)ATP@AgNPs, as a Raman probe. An antibody specific for AIV and goat anti-mouse IgG antibody were immobilized on a nitrocellulose membrane as the test and control lines, respectively. Accumulation of antibody-virus-antibody-Raman probe complex at the test line could be visualized by the naked eye, and the Raman signal could be quantified using a portable Raman instrument. The testing process for the SERS-based LFIA strips could be completed in 20 min, which avoided the time-cost of current methods for AIV analysis. In our SERS-based biosensor, we estimated the limit of detection (LOD) for H7N9 to be 0.0018 HAU. This value is approximately three orders of magnitude more sensitive than the corresponding HA assays. When testing real sample, the results of the strip test were in accordance with those from real-time PCR testing. In conclusion, the SERS-based LFIA strip proposed in this study shows tremendous potential to detect targets quickly and sensitively using an elegantly simple method.
关键词： AuAg4(cid:3)ATP@AgNPs,Surface-enhanced Raman scattering,Avian influenza virus,Lateral flow immunoassay strips
更新于2025-09-23 15:23:52
-
Photoluminescence Immunosensor Based on Bovine Leukemia Virus Proteins Immobilized on the ZnO Nanorods
摘要： Bovine leukaemia virus (BLV) proteins gp51, which are serving as antigens for specific antibodies against BLV proteins (anti-gp51), were applied as biological recognition part in the design of immunosensor devoted for the determination of anti-gp51. The efficiency of the immobilization of BLV proteins gp51 on ZnO nanorod (ZnO-NR) modified glass (ZnO-NR/glass) surface was evaluated. The formation of antigen-antibody complex on the ZnO/glass modified by the BLV proteins gp51 (gp51/ZnO-NR/glass) was investigated by the determination of changes in ZnO photoluminescence. The applicability of gp51/ZnO-NR/glass in the design of photoluminescence based immunosensor was evaluated. Bovine serum albumin (BSA) was applied for the modification of sensing gp51 layer in order to form gp51&BSA layer with advanced selectivity. Polyallylamine hydrochloride (PAH) was applied in order to improve the immobilization of gp51 and BSA based sensing layer (gp51&BSA) on the surface of ZnO-NR/glass. PAH was applied during the formation of gp51&BSA/PAH/ZnO-NR/glass structure. Some aspects of the mechanism of interaction between biomolecules (gp51, bovine serum albumin (BSA) and anti-gp51) and ZnO-NR during the preparation and action of gp51&BSA/ZnO-NR/glass- and gp51&BSA/PAH/ZnO-NR/glass-based immunosensors have been discussed.
关键词： Bovine leukemia virus (BLV),Photoluminescence,Optical immunosensor,ZnO nanorods,Antigen-antibody complex.
更新于2025-09-23 15:22:29
-
Fabrication of virus metal hybrid nanomaterials: An ideal reference for bio semiconductor
摘要： Recently, Nanotechnology has made easier utilizing plant pathogens as a potential nano-material in biomedical applications. In this research work, we have exploited a devastating plant pathogenic virus of Squash leaf curl China virus (SLCCNV), as a nano-bio template (32 nm) to fabricate the gold and silver nanomaterials. This is achieved through the direct exposure of SLCCNV to gold chloride (HAuCl4) and silver nitrate (AgNO3) precursors at sunlight, resulted into SLCCNV-metallic-hybrid nanomaterials which are synthesized quick ((cid:1)5 min) and eco-friendly. However, virus hybrid nanomaterials are fabricated through the nucleation and growth of metal precursors over the pH-activated capsid of SLCCNV. Under the controlled fabrication process, it produced a highly arrayed virus-metallic-hybrid nanomaterial at nanoscale size limit. Its properties are thoroughly studied through spectroscopic techniques (UV–Vis, DLS, Raman) and electron microscopy (HRTEM & FESEM). In a follow-up study of cytotoxicity assay, the virus and its fabricated nanomaterials show better biocompatibility features even at high concentrations. Finally, the electrical conductivities of virus-metallic-hybrid nanomaterials (Au & Ag) are determined by simple ‘‘lab on a chip” system and Keithley’s pico-ammeter. The result of electrical conductivity measurement revealed that hybrid nanomaterials have greater electrical conductive properties within the band-gap of semi-conductive materials. It is truly remarkable that a plant virus associated metal nanomaterials can be ef?ciently used as bio-semi-conductors which are the ideal one for biomedical applications.
关键词： Virus hybrid nanomaterials,Electrical conductivity,Virus template,Virus nanotechnology,Biocompatibility,Surface biomineralization
更新于2025-09-23 15:21:01
-
Single molecule localisation microscopy reveals how HIV-1 Gag proteins sense membrane virus assembly sites in living host CD4 T cells
摘要： Monitoring virus assembly at the nanoscale in host cells remains a major challenge. Human immunodeficiency virus type 1 (HIV-1) components are addressed to the plasma membrane where they assemble to form spherical particles of 100 nm in diameter. Interestingly, HIV-1 Gag protein expression alone is sufficient to produce virus-like particles (VLPs) that resemble the immature virus. Here, we monitored VLP formation at the plasma membrane of host CD4+ T cells using a newly developed workflow allowing the analysis of long duration recordings of single-molecule Gag protein localisation and movement. Comparison of Gag assembling platforms in CD4+ T cells expressing wild type or assembly-defective Gag mutant proteins showed that VLP formation lasts roughly 15 minutes with an assembly time of 5 minutes. Trapping energy maps, built from membrane associated Gag protein movements, showed that one third of the assembling energy is due to direct Gag capsid-capsid interaction while the remaining two thirds require the nucleocapsid-RNA interactions. Finally, we show that the viral RNA genome does not increase the attraction of Gag at the membrane towards the assembling site but rather acts as a spatiotemporal coordinator of the membrane assembly process.
关键词： HIV-1,Gag protein,virus assembly,CD4+ T cells,single-molecule localisation microscopy
更新于2025-09-23 15:21:01