When infecting host cells, influenza virus must move on microfilaments (MFs) at the cell periphery and then move along microtubules (MTs) through the cytosol to reach the perinuclear region for ...genome release. But how viruses switch from the actin roadway to the microtubule highway remains obscure. To settle this issue, we systematically dissected the role of related motor proteins in the transport of influenza virus between cytoskeletal filaments in situ and in real-time using quantum dot (QD)-based single-virus tracking (SVT) and multicolor imaging. We found that the switch between MF- and MT-based retrograde motor proteins, myosin VI (myoVI) and dynein, was responsible for the seamless transport of viruses from MFs to MTs during their infection. After virus entry by endocytosis, both the two types of motor proteins are attached to virus-carrying vesicles. MyoVI drives the viruses on MFs with dynein on the virus-carrying vesicle hitchhiking. After role exchanges at actin-microtubule intersections, dynein drives the virus along MTs toward the perinuclear region with myoVI remaining on the vesicle moving together. Such a “driver switchover” mechanism has answered the long-pending question of how viruses switch from MFs to MTs for their infection. It will also facilitate in-depth understanding of endocytosis.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Renal dysfunctions usually happen in viral infections and many viruses specially infect distal renal tubules, however the pathogenesis remains unknown. Here, in order to explore the pathogenesis of ...virus-related renal dysfunctions, a Pseudorabies Virus (PrV) induced kidney disease model was built on a distal tubule-on-a-chip (DTC), for the first time. The barrier structure and Na reabsorption of distal renal tubules were successfully reconstituted in DTCs. After PrV infection, results showed electrolyte regulation dysfunction in Na reabsorption for the disordered Na transporters, the broken reabsorption barrier, and the transformed microvilli. And it would lead to virus induced serum electrolyte abnormalities. This work brought us a new cognition about the advantages of organ-on-a-chip (OOC) in virus research, for it had given us a better insight into the pathogenesis of virus induced dysfunctions, based on its unique ability in function reproduction.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A donor-cell-assisted membrane biotinylation strategy was used to modify small extracellular vesicles (sEVs) while minimizing protein damage, and allowed the sEVs to be loaded onto carriers. ...Biotinylated programmed death-ligand 1 (PD-L1) positive sEVs were used to select for aptamers from a DNA library. PD-L1 negative sEVs from a homologous cell line were found to remove non-specific aptamer sequences to increase the specificity. After just four rounds, high-affinity aptamers for PD-L1 positive sEVs were selected as novel affinity reagents.
High affinity aptamers that target small extracellular vesicles displaying PD-L1 in its natural conformation were successfully selected.
Electrochemistry has been widely used to explore fundamental properties of single molecules due to its fast response and high specificity. However, the lack of efficient signal amplification ...strategies and quantitative method limit its clinical application. Here, we proposed a digital single virus electrochemical enzyme-linked immunoassay (digital ELISA) for H7N9 avian influenza virus (H7N9 AIV) counting by integration of digital analysis, bifunctional fluorescence magnetic nanospheres (bi-FMNs) with monolayer gold nanoparticles (Au NPs) modified microelectrode array (MA). Bi-FMNs are fabricated by coimmobilizing polyclonal antibody (pAb) and alkaline phosphatase (ALP). At most, one target will be captured per bi-FMNs by controlling the proportion of bi-FMNs to target concentrations (≥5:1). The introduction of digital analysis can solve signal fluctuation and the reliability of single virus detection, enabling the digital ELISA to be sensitively and accurately applied for H7N9 AIV detection with a low detection limit of 7.8 fg/mL, which is greatly promising in single biomolecular detection, early diagnosis of disease, and practical application.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
The fluorescence method has made great progress in the construction of sensitive sensors but the background fluorescence of the matrix and photobleaching limit its broad application in clinical ...diagnosis. Here, we propose a digital single virus immunoassay for multiplex virus detection by using fluorescent magnetic multifunctional nanospheres as both capture carriers and signal labels. The superparamagnetism and strong magnetic response ability of nanospheres can realize efficient capture and separation of targets without sample pretreatment. Due to their distinguishable fluorescence imaging and photostability, the nanospheres enable single-particle counting for ultrasensitive multiplexed detection. Furthermore, the integration of digital analysis provided a reliable quantitative strategy for the detection of rare targets. Based on multifunctional nanospheres and digital analysis, a digital single virus immunoassay was proposed for simultaneous detection of H9N2, H1N1, and H7N9 avian influenza virus without complex signal amplification, whose detection limits were 0.02 pg/mL. Owing to its good specificity and anti-interference ability, the method showed great potential in single biomolecules, multiplexed detection, and early diagnosis of diseases.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
A novel colorimetric assay method based on enzyme-induced metallization has been proposed for detection of alkaline phosphatase (ALP), and it was further applied to highly sensitive detection of ...avian influenza virus particles coupled with immunomagnetic separation. The enzyme-induced metallization-based color change strategy combined the amplification of the enzymatic reaction with the unique optical properties of metal nanoparticles (NPs), which could lead to a great enhancement in optical signal. The detection limit for ALP detection was 0.6 amol/50 μL which was 4–6 orders of magnitude more sensitive than other metal NP-based colorimetric methods. Moreover, this technique was successfully employed to a colorimetric viral immunosensor, which could be applied to complex samples without complicated sample pretreatment and sophisticated instruments, and a detection limit as low as 17.5 pg mL–1 was achieved. This work not only provides a simple and sensitive sensing approach for ALP and virus detection but also offers an effective signal enhancement strategy for development of a highly sensitive nonaggregation metal NP-based colorimetric assay method.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Cell‐derived microparticles (MPs) have been recently recognized as critical intercellular information conveyors. However, further understanding of their biological behavior and potential application ...has been hampered by the limitations of current labeling techniques. Herein, a universal donor‐cell‐assisted membrane biotinylation strategy was proposed for labeling MPs by skillfully utilizing the natural membrane phospholipid exchange of their donor cells. This innovative strategy conveniently led to specific, efficient, reproducible, and biocompatible quantum dot (QD) labeling of MPs, thereby reliably conferring valuable traceability on MPs. By further loading with small interference RNA, QD‐labeled MPs that had inherent cell‐targeting and biomolecule‐conveying ability were successfully employed for combined bioimaging and tumor‐targeted therapy. This study provides the first reliable and biofriendly strategy for transforming biogenic MPs into functionalized nanovectors.
Illuminating biogenic microparticles: Cell‐derived microparticles (MPs) are transformed to functionalized nanovectors by combining quantum dot (QD) labeling and efficient siRNA loading. This strategy not only reliably conferred excellent traceability and therapeutic potential on MPs, but also preserved their natural properties, thus facilitating the identification and further application of biogenic MPs. SA=streptavidin.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The 2014–16 Ebola virus (EBOV) outbreak in West Africa has attracted widespread concern. Rapid and sensitive detection methods are urgently needed for diagnosis and treatment of the disease. Here, we ...propose a novel method for EBOV detection based on efficient amplification of electroluminescent nanospheres (ENs) coupled with immunomagnetic separation. Uniform ENs are made by embedding abundant amounts of CdSe/ZnS quantum dots (QDs) into copolymer nanospheres through simple ultrasound. Compared to QDs, ENs can enhance electroluminescence (ECL) signals by approximately 85-fold, achieving a signal-to-background ratio high enough for EBOV detection. The introduction of magnetic nanobeads (MBs) can selectively separate targets from complex samples, simplifying the operation process and saving time. The presence of MBs can amplify ECL by approximately 3-fold, improving detection sensitivity. By integration of ENs with MBs, a sensitive electroluminescence biosensor is established for EBOV detection. The linear range is 0.02–30 ng/mL with a detection limit of 5.2 pg/mL. This method provides consistent reproducibility, specificity, and anti-interference ability and is highly promising in clinical diagnosis applications.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
The detection of circulating tumor cells (CTCs), a kind of "liquid biopsy", represents a potential alternative to noninvasive detection, characterization and monitoring of carcinoma. Many previous ...studies have shown that the number of CTCs has a significant relationship with the stage of cancer. However, CTC enrichment and detection remain notoriously difficult because they are extremely rare in the bloodstream. Herein, aided by a microfluidic device, an immunomagnetic separation system was applied to efficiently capture and in situ identify circulating tumor cells. Magnetic nanospheres (MNs) were modified with an anti-epithelial-cell-adhesion-molecule (anti-EpCAM) antibody to fabricate immunomagnetic nanospheres (IMNs). IMNs were then loaded into the magnetic field controllable microfluidic chip to form uniform IMN patterns. The IMN patterns maintained good stability during the whole processes including enrichment, washing and identification. Apart from its simple manufacture process, the obtained microfluidic device was capable of capturing CTCs from the bloodstream with an efficiency higher than 94%. The captured cells could be directly visualized with an inverted fluorescence microscope in situ by immunocytochemistry (ICC) identification, which decreased cell loss effectively. Besides that, the CTCs could be recovered completely just by PBS washing after removal of the permanent magnets. It was observed that all the processes showed negligible influence on cell viability (viability up to 93%) and that the captured cells could be re-cultured for more than 5 passages after release without disassociating IMNs. In addition, the device was applied to clinical samples and almost all the samples from patients showed positive results, which suggests it could serve as a valuable tool for CTC enrichment and detection in the clinic.
Sulfoxaflor, a sulfoximine insecticide, could efficiently control many insect pests of sap-feeding. Microbial degradation of sulfoxaflor and the enzymatic mechanism involved have not been studied to ...date. A bacterial isolate JW2 that transforms sulfoxaflor to X11719474 was isolated and identified as Aminobacter sp. CGMCC 1.17253. Both the recombinant Escherichia coli strain harboring the Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) gene and the pure NHase acquired sulfoxaflor-degrading ability. Aminobacter sp. CGMCC 1.17253 NHase is a typical cobalt-containing NHase content of subunit α, subunit β, and an accessory protein, and the three-dimensional homology model of NHase was built. Substrate specificity tests showed that NHase catalyzed the conversion of acetamiprid, thiacloprid, indolyl-3-acetonitrile, 3-cyanopyridine, and benzonitrile into their corresponding amides, indicating its broad substrate specificity. This is the first report of the pure bacteria degradation of the sulfoxaflor residual in the environment and reveals the enzymatic mechanism mediated by Aminobacter sp. CGMCC 1.17253.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM, UPUK
