Identification of cellular receptors used by coronavirus (CoV) entry into the host cells is critical to an understanding of pathogenesis and to development of intervention strategies. The fourth CoV ...genus,
, evolutionarily related to the
, has just been defined recently. In the current study, we demonstrate that porcine aminopeptidase N (pAPN) acts as a cross-genus CoV functional receptor for both enteropathogenic porcine deltacoronovirus (PDCoV) and alphacoronovirus (AlphaCoV) (transmissible gastroenteritis virus TGEV) based upon three lines of evidence. First, the soluble S1 protein of PDCoV bound to the surface of target porcine cell lines known to express pAPN as efficiently as TGEV-S1, which could be blocked by soluble pAPN pretreatment. Second, both PDCoV-S1 and TGEV-S1 physically recognized and interacted with pAPN by coimmunoprecipitation in pAPN cDNA-transfected cells and by dot blot hybridization assay. Finally, exogenous expression of pAPN in refractory cells conferred susceptibility to PDCoV-S1 binding and to PDCoV entry and productive infection. PDCoV-S1 appeared to have a lower pAPN-binding affinity and likely consequent lower infection efficiency in pAPN-expressing refractory cells than TGEV-S1, suggesting that there may be differences between these two viruses in the virus-binding regions in pAPN. This study paves the way for dissecting the molecular mechanisms of PDCoV-host interactions and pathogenesis as well as facilitates future vaccine development and intervention strategies against PDCoV infection.
The emergence of new human and animal coronaviruses is believed to have occurred through interspecies transmission that is mainly mediated by a species-specific receptor of the host. Among the four genera of the
, a couple of functional receptors for the representative members in the genera
and
have been identified, whereas receptors for
and
, which are believed to originate from birds, are still unknown. Porcine coronaviruses, including the newly discovered porcine deltacoronavirus (PDCoV) associated with diarrhea in newborn piglets, have posed a serious threat to the pork industry in Asia and North America. Here, we report that PDCoV employs the alphacoronavirus TGEV functional receptor porcine aminopeptidase N (pAPN) for cellular entry, demonstrating the usage of pAPN as a cross-genus CoV functional receptor. The identification of the PDCoV receptor provides another example of the expanded host range of CoV and paves the way for further investigation of PDCoV-host interaction and pathogenesis.
The circular intensity differential scattering (CIDS), i.e. the normalized Mueller matrix element -S
/S
, can be used to detect the helical structures of DNA molecules in biological systems, however, ...no CIDS measurement from single particles has been reported to date. We report an innovative method for measuring CIDS phase functions from single particles individually flowing through a scattering laser beam. CIDS signals were obtained from polystyrene latex (PSL) microspheres with or without coating of DNA molecules, tryptophan particles, and aggregates of B. subtilis spores, at the size of 3 μm in diameter. Preliminary results show that this method is able to measure CIDS phase function in tens of microseconds from single particles, and has the ability to identify particles containing biological molecules.
This study focuses on organic carbon (OC) aerosols, including natural biological aerosols, in the Earth's troposphere, and on laser‐induced fluorescence (LIF) spectral methods for studying these ...aerosols. LIF spectra of atmospheric OC and biological aerosols (having diameters greater than approximately 3 μm) measured at New Haven, Connecticut, and Las Cruces, New Mexico, are reported. A hierarchical clustering method was used to cluster approximately 90% of the single‐particle LIF spectra into 8–10 groups. Some of these groups have spectra that are similar to spectra of some important classes of atmospheric aerosol, such as humic/fulvic acids and humic‐like substances, bacteria, cellulose, marine aerosol, and polycyclic aromatic hydrocarbons (PAH). A comparison with previous measurements made at Adelphi, Maryland, reveals that the most highly populated clusters found at Adelphi, and some of the less populated ones, also appear in the LIF spectra at New Haven and Las Cruces, even though the regional climates at these locations is different (New England/Atlantic Coastal, for New Haven and Adelphi, and Chihuahuan Desert for Las Cruces), and the measurements were made in different seasons. The results are consistent with some (perhaps most) of the fluorors in OC and biological atmospheric aerosols being common to these three sites. On average, spectra characteristic of humic/fulvic acids and humic‐like substances (HULIS) comprise 28–43% of fluorescent particles at all three sites; whereas cellulose‐like spectra contribute only 1–3%.
•Zn-MOF material named Zn(L)n was successfully synthesized by solvothermal method.•Zn-MOF exhibits a utp uninodal 3-connected 3D 2-interpenetrating framework with the point symbol (103).•Zn-MOF is a ...potential fluorescent material that can selectively and sensitively fluorescent sensing NB.
Nitrobenzene (NB) can cause serious harm to ecosystems and human health. In order to identify and detect NB effectively, a micro-porous Zn-based metal-organic framework (Zn-MOF) material was prepared. Zn-MOF material named Zn(L)n was successfully synthesized by solvothermal method, using 1,3,5-tris (3-carboxy-triazole-methylene)-2,4,6-tritoluene (H3L) as organic ligand. Its stucture was characterized by X-ray single-crystal diffraction, elemental analysis, IR spectra and thermogravimetric (TG) analysis. X-ray single-crystal diffraction analysis exhibits that Zn-MOF belongs to the orthorhombic crystal system, space group Pbcn. The central Zn(II) ion exhibits a octahedron {ZnN3O3} coordination geometry. Topological analysis shows that Zn-MOF exhibits a utp uninodal 3-connected 3D 2-interpenetrating framework with the point symbol (103). Furthermore, the fluorescence quenching experimental results show that Zn-MOF is a potential fluorescent material that can selectively and sensitively fluorescent sensing NB.
A Zn-MOF was successfully synthesized. The fluorescence quenching experimental results show that Zn-MOF is a potential fluorescent material that can selectively and sensitively fluorescent sensing NB. Display omitted
•A novel heat transfer model of PTC thermal control material has been proposed.•This model considers the internal heat transfer of the control system.•The effect of thermal conductivity, heat ...capacity and thermal contract resistance has been studied.•The dynamic thermal control performance of PTC material has been studied.
Positive temperature coefficient (PTC) material is widely used in thermal control due to its unique characteristics. In this paper, a novel heat transfer model of PTC material is proposed with consideration given to the internal heat transfer characteristics of the model which was ignored in the previous model, and it is validated by conducting experiment. Based on this novel heat transfer model, the effects exerted by thermal conductivity, heat capacity and thermal contact resistance on the thermal control of PTC material that have never been studied in previous work are investigated. In this paper, the PTC material with large heat capacity will extend the equilibrium time of the controlled device significantly. Besides, the dynamic thermal control performance of PTC material is verified by carrying out simulation. Herein, thermal control of PTC material under three different ambient temperature conditions is studied. As indicated by the results, PTC material has better thermal control performance under variable ambient temperatures. When the ambient temperature varies periodically with 5 °C amplitude and for a period of more than 300 s, the temperature of controlled device barely changes.
•Speckle size from two-dimensional angular optical scattering (TAOS) is strongly negatively correlated with cluster size of aerosol.•Simulations show that analysis of two-dimensional angular optical ...scattering (TAOS) is able to distinguish between non-absorbing, weakly-absorbing, and strongly-absorbing single aerosol particles.
Measuring the absorption of a single aerosol particle is a challenging endeavor. Of the few techniques available, none are suitable for measuring the single-particle absorption of coarse-mode nonspherical aerosols. Analysis of two-dimensional angular optical scattering (TAOS) patterns provide a possible pathway to perform this measurement. Using a Multiple-Sphere T-Matrix (MSTM) code, we simulate the captured TAOS patterns with geometries similar to a previously designed instrument. By analyzing the size of the speckle and the integrated irradiance of these simulated TAOS patterns, we are able to distinguish between high-absorbing, weak-absorbing, and non-absorbing particles over the size range of 2 µm to 10 µm. In particular, the speckle present in the scattering patterns provides a means to estimate the size of the particle. Once the size of the particle is known, the integrated irradiance provides insight into the absorption of the particle.
Swine enteric alphacoronavirus (SeACoV), also known as swine acute diarrhea syndrome coronavirus (SADS-CoV), belongs to the species Rhinolophus bat coronavirus HKU2. Herein, we report on the primary ...characterization of SeACoV in vitro. Four antibodies against the SeACoV spike, membrane, nucleocapsid and nonstructural protein 3 capable of reacting with viral antigens in SeACoV-infected Vero cells were generated. We established a DNA-launched SeACoV infectious clone based on the cell adapted passage-10 virus and rescued the recombinant virus with a unique genetic marker in cultured cells. Six subgenomic mRNAs containing the leader-body junction sites, including a bicistronic mRNA encoding the accessory NS7a and NS7b genes, were experimentally identified in SeACoV-infected cells. Cellular ultrastructural changes induced by SeACoV infection were visualized by electron microscopy. The availability of the SeACoV infectious clone and a panel of antibodies against different viral proteins will facilitate further studies on understanding the molecular mechanisms of SeACoV replication and pathogenesis.
•Generation of four antibodies to distinct SeACoV protein for detection of SeACoV infection.•Development of a DNA-launched reverse genetics system for SeACoV.•Recombinant SeACoV with a genetic marker had similar growth kinetics to the parental virus.•Identification of all SeACoV subgenomic mRNAs containing the leader-body junction sites.•SeACoV infection induces cellular ultrastructural changes.
Toroviruses (ToVs), closely related but genetically distinct from coronaviruses, are known to infect horses, cows, pigs, goats and humans, mainly causing enteritic disorders. However, due to the lack ...of an adaptive culture system, porcine ToV (PToV) has received less attention. In this study, we developed a novel serological detection method based on the PToV envelope spike subunit 1 (S1) protein for the first time, and compared it to an existing indirect enzyme‐linked immunosorbent assay (ELISA) based on the nucleocapsid protein. By using the S1‐based ELISA, we carried out the first seroepidemiological survey of PToV in China, assaying both specific IgG and IgA responses in 1,037 serum samples collected from diarrheic pigs in eastern China. There was a relatively high incidence of seropositivity in pigs of different ages, especially one‐week‐old piglets and sows (78% and 43%), the former probably reflecting maternal antibodies. Furthermore, 3/20 (15%) of faecal samples collected from one PToV‐seropositive swine herd in Zhejiang province tested positive by RT‐PCR. The complete PToV genome was sequenced from one of these samples, and its phylogenetic relationship with other full‐length PToV sequences available in GenBank was determined. Our data provide the first serological evidence for PToV infection in pigs from China, which will help elucidate the potential pathogenicity of PToV in pigs.
Porcine deltacoronavirus (PDCoV) is one of the emerged coronaviruses posing a significant threat to the swine industry. Previous work showed the presence of a viral accessory protein NS6 in ...PDCoV-infected cells. In this study, we detected the expression of the NS6 protein in small intestinal tissues of PDCoV-infected piglets. In addition, SDS-PAGE and Western blot analysis of sucrose gradient-purified virions showed the presence of a 13-kDa NS6 protein. Further evidences of the presence of NS6 in the PDCoV virions were obtained by immunogold staining of purified virions with anti-NS6 antiserum, and by immunoprecipitation of NS6 from purified virions. Finally, the anti-NS6 antibody was not able to neutralize PDCoV in cultured cells. These data establish for the first time that the accessory protein NS6 is expressed during infection in vivo and incorporated into PDCoV virions.
•PDCoV accessory protein NS6 is expressed during infection in vivo.•A 13-KDa NS6 protein is detected in purified PDCoV virions.•NS6 is incorporated into PDCoV particles by immunogold labeling with anti-NS6.•Anti-NS6 does not exhibit neutralizing activity against PDCoV.
An advanced rotating aerosol chamber was developed to study the changes of fluorescence spectral profile and intensity, the viability and the quantitative polymerase chain reaction (qPCR) signal of ...Escherichia coli aerosol particles as they are exposed to simulated atmospheric conditions over time. These conditions included relative humidity (RH) below 30% or ∼75%, ozone ∼100 ppb, volatile organic compounds (VOCs) α-pinene (∼5 ppb) or toluene (∼45 ppb), and simulated solar (SS) irradiation. Individual experiments examined the effects of these conditions applied individually and in combination. Experimental results demonstrate that the 263 nm laser excited UV fluorescence band (280-400 nm) showed the greatest rate of decrease, and the visible band (400-580 nm) generally had a smaller change rate which followed the change in the UV band. The 351 nm excited visible band (380-650 nm) had the smallest decay rates, and sometimes increased, when exposed to ozone, high RH, and VOCs. Generally, the viability, qPCR signal intensity, and the fluorescence intensity decayed faster when more variables were applied in combination. Simulated solar irradiation was the most dominant factor in the aging process, followed by the combination of high RH and ozone. Interestingly, the decay of fluorescence and qPCR signal do not appear to correlate directly with loss in viability. Therefore, additional studies are expected to further understand the mechanisms by which atmospheric chemical processes impact viability, qPCR signal intensity, and the fluorescence of biological aerosols.
PDF
