Portable electrochemical sensor for adrenaline detection using CoNi-MOF-based CS-PAM hydrogel.

The development of a portable smartphone-based electrochemical sensor for analyzing adrenaline levels in real samples can make a great contribution to the research community worldwide. In order to achieve this goal, the key challenge is to build sensing interfaces with excellent electrocatalytic properties. In this work, microspherical bimetallic metal-organic frameworks (CoNi-MOF) consisting of nanoclusters were first synthesized using a hydrothermal method. On this basis, the catalytic activity of pure chitosan-polyacrylamide hydrogel (CS-PAM) was modulated by adding different amounts of CoNi-MOF during the in-situ synthesis of CS-PAM. Finally, a portable electrochemical detection system based on CS-PAM was established for the detection of adrenaline. A series of resulting composite hydrogels with a large specific surface area, abundant active sites, and unique network structure facilitate the enrichment and catalysis of adrenaline molecules. Under optimal conditions, the analytical platform constructed by using CoNi-MOF-based CS-PAM has the advantages of a wide detection range (0.5-10 and 10-2500 µM), a low detection limit (0.167 µM), and high sensitivity (0.182 and 0.133 µA·µM·cm-2). In addition, the sensor maintains selective detection of the target in the presence of many different types of interferences, and the current response is not significantly reduced even after 60 cycles of testing. We strongly believe that the designed smart portable sensing can realize the accurate determination of adrenaline in complex systems, and this study can provide new ideas for the research of MOFs-based hydrogels in electrochemical analysis.

Innate immune response to SARS-CoV-2 infection contributes to neuronal damage in human iPSC-derived peripheral neurons.

Severe acute respiratory coronavirus 2 (SARS-CoV-2) causes neurological disease in the peripheral and central nervous system (PNS and CNS, respectively) of some patients. It is not clear whether SARS-CoV-2 infection or the subsequent immune response are the key factors that cause neurological disease. Here, we addressed this question by infecting human induced pluripotent stem cell-derived CNS and PNS neurons with SARS-CoV-2. SARS-CoV-2 infected a low number of CNS neurons and did not elicit a robust innate immune response. On the contrary, SARS-CoV-2 infected a higher number of PNS neurons. This resulted in expression of interferon (IFN) λ1, several IFN-stimulated genes and proinflammatory cytokines. The PNS neurons also displayed alterations characteristic of neuronal damage, as increased levels of sterile alpha and Toll/interleukin receptor motif-containing protein 1, amyloid precursor protein and α-synuclein, and lower levels of cytoskeletal proteins. Interestingly, blockade of the Janus kinase and signal transducer and activator of transcription pathway by Ruxolitinib did not increase SARS-CoV-2 infection, but reduced neuronal damage, suggesting that an exacerbated neuronal innate immune response contributes to pathogenesis in the PNS. Our results provide a basis to study coronavirus disease 2019 (COVID-19) related neuronal pathology and to test future preventive or therapeutic strategies.

Herpes simplex virus type 1 modifies the protein composition of extracellular vesicles to promote neurite outgrowth and neuroinfection.

The highly prevalent herpes simplex virus type 1 (HSV-1) causes a range of diseases, including cold sores, blinding keratitis, and life-threatening encephalitis. HSV-1 initially replicates in epithelial cells, enters the peripheral nervous system via neurites, and establishes lifelong infection in the neuronal cell bodies. Neurites are highly dynamic structures that grow or retract in response to attractive or repulsive cues, respectively. Here, we show that infection with HSV-1, but not with a mutant virus lacking glycoprotein G (gG), reduced the repulsive effect of epithelial cells on neurite outgrowth and facilitated HSV-1 invasion of neurons. HSV-1 gG was required and sufficient to induce neurite outgrowth by modifying the protein composition of extracellular vesicles, increasing the amount of neurotrophic and neuroprotective proteins, including galectin-1. Antibodies directed against galectin-1 neutralized the capacity of extracellular vesicles released from HSV-1-infected cells to promote neurite outgrowth. Our study provides new insights into the neurotropism of HSV-1 and identifies a viral protein that modifies the protein composition of extracellular vesicles to stimulate neurite outgrowth and invasion of the nervous system.IMPORTANCEHerpes simplex virus type 1 (HSV-1) must infect neurites (or nerve endings) to establish a chronic infection in neurons. Neurites are highly dynamic structures that retract or grow in the presence of repulsive or attractive proteins. Some of these proteins are released by epithelial cells in extracellular vesicles and act upon interaction with their receptor present on neurites. We show here that HSV-1 infection of epithelial cells modulated their effect on neurites, increasing neurite growth. Mechanistically, HSV-1 glycoprotein G (gG) modifies the protein composition of extracellular vesicles released by epithelial cells, increasing the amount of attractive proteins that enhance neurite outgrowth and facilitate neuronal infection. These results could inform of therapeutic strategies to block HSV-1 induction of neurite outgrowth and, thereby, neuronal infection.

Elucidation of Substantial Differences in Ring-Opening Polymerization Outcomes from Subtle Variation of Glucose Carbonate-Based Monomer Substitution Patterns and Substituent Types.

The substituents present upon five-membered bicyclic glucose carbonate monomers were found to greatly affect the reactivities and regioselectivities during ring-opening polymerization (ROP), which contrast in significant and interesting ways from previous studies on similar systems, while also leading to predictable effects on the thermal properties of the resulting polycarbonates. Polymerization behaviors were probed for a series of five five-membered bicyclic 2,3-glucose-carbonate monomers having 4,6-ether, -carbonate, or -sulfonyl urethane protecting groups, under catalysis with three different organobase catalysts. Irrespective of the organobase catalyst employed, regioregular polycarbonates were obtained via ROP of monomers with ether substituents, while the backbone connectivities of polymers derived from monomers with carbonate protecting groups suffered transcarbonylation reactions, resulting in irregular backbone connectivities and broad molar mass distributions. The sulfonyl urethane-protected monomers were unable to undergo organobase-catalyzed ROP, possibly due to the acidity of the proton in urethane functionality. The thermal behaviors of polycarbonates with ether and carbonate pendant groups were investigated in terms of thermal stability and glass transition temperature (Tg). A two-stage thermal decomposition was observed when tert-butyloxycarbonyl (BOC) groups were employed as protecting side chains, while all other polycarbonates presented high thermal stabilities with a single-stage thermal degradation. Tg was greatly affected by side-chain bulkiness, with values ranging from 39 to 139 °C. These fundamental findings of glucose-based polycarbonates may facilitate the development of next-generation sustainable highly functional materials.

Colonization of peripheral ganglia by herpes simplex virus type 1 and 2.

Herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) infect and establish latency in neurons of the peripheral nervous system to persist lifelong in the host and to cause recurrent disease. During primary infection, HSV replicates in epithelial cells in the mucosa and skin and then infects neurites, highly dynamic structures that grow or retract in the presence of attracting or repelling cues, respectively. Following retrograde transport in neurites, HSV establishes latency in the neuronal nucleus. Viral and cellular proteins participate in the chromatinization of the HSV genome that regulates gene expression, persistence, and reactivation. HSV-2 modulates neurite outgrowth during primary infection and upon reactivation, probably to facilitate infection and survival of neurons. Whether HSV-1 modulates neurite outgrowth and the underlying mechanism is currently under investigation. This review deals with HSV-1 and HSV-2 colonization of peripheral neurons, with a focus on the modulation of neurite outgrowth by these viruses.

Ultrasmall, elementary and highly translational nanoparticle X-ray contrast media from amphiphilic iodinated statistical copolymers.

To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity, and well-defined spatial and temporal resolutions, a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media (nano-XRCM) as dual-modality imaging agents for positron emission tomography (PET) and computed tomography (CT) has been established. Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide) acrylate monomers, the amphiphilic statistical iodocopolymers (ICPs) could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations (>140 mg iodine/mL water) and comparable viscosities to conventional small molecule XRCM. The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca. 10 nm in water was confirmed by dynamic and static light scattering techniques. In a breast cancer mouse model, in vivo biodistribution studies revealed that the 64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents. PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals, while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection, enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.

The performance of Miscanthus hybrids in saline-alkaline soil.

Cultivating the dedicated biomass crop Miscanthus on marginal land is a sustainable means of avoiding competition with food crops for arable land. A large proportion of global marginal land is saline-alkaline; however, little is known about the performance of Miscanthus in saline-alkaline soil. In this study, Miscanthus × giganteus and ten other Miscanthus hybrids grown in the Yellow River Delta were exposed to low and saline-alkaline soils during the 2016-2018 growing season to evaluate the agronomic traits, biomass quality and the potential productive index of eleven Miscanthus genotypes. Plant biomass, plant height, and tiller number significantly decreased in high saline-alkaline soil. In particular, the average plant biomass of ten Miscanthus hybrids in low saline-alkaline soil in 2017 and 2018 were 0.21 and 2.25 kg per plant, respectively, and in high saline-alkaline soil were 0.13 and 0.65 kg per plant, respectively. Cell wall, cellulose, and nitrogen content of all genotypes significantly decreased in high saline-alkaline soil, while hemicellulose, ash, sodium, potassium, magnesium, and calcium content significantly increased. However, high saline-alkaline soil had no observable impact on lignin content of Miscanthus biomass. The effect of high saline-alkaline on biomass quality parameters could provide important information for the application of Miscanthus biomass in saline-alkaline soil. The selected genotypes (A5) could be considered as breeding materials in saline-alkaline soil.

High-Luminescence Electrospun Polymeric Microfibers In Situ Embedded with CdSe Quantum Dots with Excellent Environmental Stability for Heat and Humidity Wearable Sensors.

In this paper, hydrophobic luminescent CdSe quantum dots are successfully dispersed in a mixture of styrene and methyl methacrylate through the oleic to methacrylic acid ligand exchange. Further in situ solution polymerization of the quantum dots in a mixture of styrene and methyl methacrylate followed by electrospinning allowed us to prepare luminescence hybrid styrene-co-methyl methacrylate fibers embedded with quantum dots. CdSe@P(S+MMA) hybrid fibers with 27% quantum yield showed excellent moisture, heat and salt resistance with a photoluminescence output below 120 °C. When dry heated, the hybrid fibers of the fluorescence signals decreased with temperature to 79%, 40%, 28%, 20% and 13% at 120 °C, 140 °C, 160 °C, 180 °C and 200 °C, respectively, due the to the chemical degradation of CdSe QDs. Such hybrid fibers show the potential to manufacture wearable moisture- and heat-sensing protective clothing in a 120-200 °C range due to the thermal-induced quenching of quantum dot photoluminescence.

Topological Design of Highly Anisotropic Aligned Hole Transporting Molecular Bottlebrushes for Solution-Processed OLEDs.

Polyvinyl polymers bearing pendant hole transport functionalities have been extensively explored for solution-processed hole transport layer (HTL) technologies, yet there are only rare examples of high anisotropic packing of the HT moieties of these polymers into substrate-parallel orientations within HTL films. For small molecules, substrate-parallel alignment of HT moieties is a well-established approach to improve overall device performance. To address the longstanding challenge of extension from vapor-deposited small molecules to solution-processable polymer systems, a fundamental chemistry tactic is reported here, involving the positioning of HT side chains within macromolecular frameworks by the construction of HT polymers having bottlebrush topologies. Applying state-of-the-art polymer synthetic techniques, various functional subunits, including triphenylamine (TPA) for hole transport and adhesion to the substrate, and perfluoro alkyl-substituted benzyloxy styrene for migration to the air interface, were organized with exquisite control over the composition and placement throughout the bottlebrush topology. Upon assembling the HT bottlebrush (HTB) polymers into monolayered HTL films on various substrates through spin-casting and thermal annealing, the backbones of HTBs were vertically aligned while the grafts with pendant TPAs were extended parallel to the substrate. The overall design realized high TPA π-stacking along the out-of-plane direction of the substrate in the HTLs, which doubled the efficiency of organic light-emitting diodes compared with linear poly(vinyl triphenylamine)s.

Complexities of Regioselective Ring-Opening vs Transcarbonylation-Driven Structural Metamorphosis during Organocatalytic Polymerizations of Five-Membered Cyclic Carbonate Glucose Monomers.

Rigorous investigations of the organobase-catalyzed ring-opening polymerizations (ROPs) of a series of five-membered cyclic carbonate monomers derived from glucose revealed that competing transcarbonylation reactions scrambled the regiochemistries of the polycarbonate backbones. Regioirregular poly(2,3-α-d-glucose carbonate) backbone connectivities were afforded by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-catalyzed ROPs of three monomers having different cyclic acetal protecting groups through the 4- and 6-positions. Small molecule studies conducted upon isolated unimers and dimers indicated a preference for Cx-O2 vs Cx-O3 bond cleavage from tetrahedral intermediates along the pathways of addition-elimination mechanisms when the reactions were performed at room temperature. Furthermore, treatment of isolated 3-unimer or 2-unimer, having the carbonate linkage in the 3- or 2-position as obtained from either Cx-O2 or Cx-O3 bond cleavage, respectively, gave the same 74:26 (3-unimer:2-unimer) ratio, confirming the occurrence of transcarbonylation reactions with a preference for 3-unimer vs. 2-unimer formation in the presence of organobase catalyst at room temperature. In contrast, unimer preparation at -78 °C favored Cx-O3 bond cleavage to afford a majority of 2-unimer, presumably due to a lack of transcarbonylation side reactions. Computational studies supported the experimental findings, enhancing fundamental understanding of the regiochemistry resulting from the ring-opening and subsequent transcarbonylation reactions during ROP of glucose carbonates. These findings are expected to guide the development of advanced carbohydrate-derived polymer materials by an initial monomer design via side chain acetal protecting groups, with the ability to evolve the properties further through later-stage structural metamorphosis.

Value of GRACE and SYNTAX scores for predicting the prognosis of patients with non-ST elevation acute coronary syndrome.

BACKGROUND: GRACE and SYNTAX scores are important tools to assess prognosis in non-ST-elevation acute coronary syndrome (NSTE-ACS). However, there have been few studies on their value in patients receiving different types of therapies. AIM: To explore the value of GRACE and SYNTAX scores in predicting the prognosis of patients with NSTE-ACS receiving different types of therapies. METHODS: The data of 386 patients with NSTE-ACS were retrospectively analyzed and categorized into different groups. A total of 195 patients who received agents alone comprised the medication group, 156 who received medical therapy combined with stents comprised the stent group, and 35 patients who were given agents and underwent coronary artery bypass grafting (CABG) comprised the CABG group. General information was compared among the three groups. GRACE and SYNTAX scores were calculated. The association between the relationship between GRACE and SYNTAX scores and the occurrence of major adverse cardiovascular events (MACEs) was analyzed. Pearson's correlation analysis was used to determine the factors influencing prognosis in patients with NSTE-ACS. Univariate and multivariate analyses were conducted to analyze the predictive value of GRACE and SYNTAX scores for predicting prognosis in patients with NSTE-ACS using the Cox proportional-hazards model. RESULTS: The incidence of MACE increased with the elevation of GRACE and SYNTAX scores (all P < 0.05). The incidence of MACE was 18.5%, 36.5%, and 42.9% in the medication group, stent group, and CABG group, respectively. By comparison, the incidence of MACE was significantly lower in the medication group than in the stent and CABG groups (all P < 0.05). The incidence of MACE was 6.2%, 28.0% and 40.0% in patients with a low GRACE score in the medication group, stent group, and CABG group, respectively (P < 0.05). The incidence of MACE was 31.0%, 30.3% and 42.9% in patients with a medium GRACE score in the medication group, stent group, and CABG group, respectively (P > 0.05). The incidence of MACE was 16.9%, 46.2%, and 43.8% in patients with a high GRACE score in the medication group, stent group, and CABG group, respectively (P < 0.05). The incidence of MACE was 16.2%, 35.4% and 60.0% in patients with a low SYNTAX score in the medication group, stent group, and CABG group, respectively (P < 0.05). The incidence of MACE was 37.5%, 40.9%, and 41.7% in patients with a medium SYNTAX score in the medication group, stent group, and CABG group, respectively (P > 0.05). MACE incidence was 50.0%, 75.0%, and 25.0% in patients with a high SYNTAX score in the medication group, stent group, and CABG group, respectively (P < 0.05). Univariate Cox regression analyses showed that both GRACE score (hazard ratio [HR] = 1.212, 95% confidence interval [CI]: 1.083 to 1.176; P < 0.05) and SYNTAX score (HR = 1.160, 95%CI: 1.104 to 1.192; P < 0.05) were factors influencing MACE (all P < 0.05). Multivariate Cox regression analyses showed that GRACE (HR = 1.091, 95%CI: 1.015 to 1.037; P < 0.05) and SYNTAX scores (HR = 1.031, 95%CI: 1.076 to 1.143; P < 0.05) were independent predictors of MACE (all P < 0.05). CONCLUSION: GRACE and SYNTAX scores are of great value for evaluating the prognosis of NSTE-ACS patients, and prevention and early intervention strategies should be used in clinical practice targeting different risk scores.

Synthesis and Optical Properties of In2S3-Hosted Colloidal Zn-Cu-In-S Nanoplatelets.

High-efficiency photoluminescence quaternary hexagon Zn-Cu-In-S (ZCIS) nanoplatelets (NPls) have been synthesized by a two-step cation exchange method, which starts with the In2S3 NPls followed by the addition of Cu and Zn. It is the first time that In2S3 NPls are used as templates to synthesize ZCIS NPls. In this paper, the reaction temperature of In2S3 is essential for the formation of NPls. The photoluminescence wavelength of NPls can be tuned by adjusting the temperature of Cu addition. To enhance the stability of the resulting NPls and to improve their optical properties, we introduced Zn2+ and obtained ZCIS NPls by cation exchange on the surface. It is worth noting that the obtained ZCIS NPls show a shorter fluorescence lifetime than other ternary copper sulfide-based NPls. This work provides a new way to synthesize high-efficiency, nontoxic, and no byproduct ZCIS NPls.

Protective effects of ß-glucan as adjuvant combined inactivated Vibrio harveyi vaccine in pearl gentian grouper.

Vaccination is one of the strategies for preventing Vibrio harveyi infection in marine-cultured animals. In this study, we prepared a formalin-killed cells of V. harveyi ZJ0603 vaccine (FKC) combined with ß-glucan to immune pearl gentian grouper. The results indicated that the expression levels of IgM, TNF-α, MHC-Iα, IL-1ß and IL-16 significantly increased in the spleen of the vaccinated fish. Antibody titers, activities of lysozyme and superoxide dismutase were significantly prompted in blood of the vaccinated fish. After 35 d post-vaccination, all fish were challenged intraperitoneally by virulent V. harveyi, and the relative percentage of survival (RPS) of FKC+ß-glucan, FKC, ß-glucan and PBS were 68 ± 5.7%, 55 ± 8.5%, 42 ± 7.5% and 32 ± 6.9%, respectively. These results demonstrated that ß-glucan could be as a potential adjuvant of FKC and provide good protective effect against V. harveyi infection in the pearl gentian grouper culture.

Natural co-infection with two virulent wild strains of Marek's disease virus in a commercial layer flock.

Marek's disease (MD) is a highly contagious lymphoproliferative poultry disease caused by the oncogenic herpesvirus, Marek's disease virus (MDV). MDV strains have shown a continued evolution of virulence leading to immune failure, and MD cases continue to occur. Co-infection of virulent MDV strains is an important factor leading to viral evolution and host immune failure. This study conducted a laboratory diagnosis and analysis of a MDV infected flock. Testing showed that all samples were MDV positive. PCR detection identified a variable 132-base pair repeat (132-bpr) sequence copy number. This indicated that two virulent strains of MDV were co-infecting the flock. Therefore, we performed homology, sequence alignment, and phylogenetic tree analysis of MDV variant genes including meq, pp38, and RLORF4. Two MDV strains had co-infected the flock; one was the 132bpr two-copy characteristic strain (AH2C) and the other was a 132bpr three-copy characteristic strain (AH3C). Specific mutations in AH3C were found, suggesting that it is a new variant strain. Furthermore, the viral load of the two strains in vivo indicated that both strains had high and similar replication ability. There was no significant difference in the proportion of positive samples of the two strains causing disease. In the whole flock, neither strain displayed an obvious advantage. However, there was a dominant strain in individual chickens, with the exception of one sample. This study reported the co-infection regularity of two virulent MDV strains in the same flock, and even in the same chicken in field conditions. In the context of overall epidemiology, this study is a useful reference.

Differential expression of type I interferon mRNA and protein levels induced by virulent Marek's disease virus infection in chickens.

Marek's disease virus (MDV), an α-herpesvirus targeting avian species, causes fatal Marek's disease (MD) in chickens. The host interferon (IFN) responses play a key role in resisting viral infection. However, host IFN responses following MDV infection in the chicken central immune organs (thymus and bursa of Fabricius), which contain numerous MDV target cells, is poorly understood. In this study, we performed animal experiments in specific pathogen-free chickens infected with two virulent MDV strains (BS/15 and Md5) or without infection as negative controls. Specifically, the type I IFN (IFN-α and IFN-ß) transcriptional and proteomic expression levels at 7, 10, 14, 17, and 21 days post infection (dpi) were detected and analyzed. Our results indicated that the mRNA and protein expression levels of IFN-α and IFN-ß in the thymus and bursa of Fabricius were mainly downregulated in cytolytic infection (such as 10 dpi) and reactivation (such as 17 dpi) stages, but not the latent (such as 14 dpi) stage of MDV infection, which was determined by comprehensively analyzing the MDV viral load and immune organ damage caused by MDV infection. These data suggest that MDV could inhibit the expression of host type I IFNs, which may be involved in the MDV-induced host immunosuppression and contribute to the immune escape of MDV from host immunity. Furthermore, we found that the downregulated expression of the host type I IFNs induced by BS/15 and Md5 infection was significantly different, which we speculated may be related to the diverse virulence and pathogenicity of MDV strains. In conclusion, our study demonstrated that MDV mostly inhibited the expression of type I IFNs in infected hosts, which may be associated to its pathogenesis.

Assessment of Copper Nanoclusters for Accurate in Vivo Tumor Imaging and Potential for Translation.

Nanoparticles have been widely used for preclinical cancer imaging. However, their successful clinical translation is largely hampered by potential toxicity, unsatisfactory detection of malignancy at early stages, inaccurate diagnosis of tumor biomarkers, and histology for imaging-guided treatment. Herein, a targeted copper nanocluster (CuNC) is reported with high potential to address these challenges for future translation. Its ultrasmall structure enables efficient renal/bowel clearance, minimized off-target effects in nontargeted organs, and low nonspecific tumor retention. The pH-dependent in vivo dissolution of CuNCs affords minimal toxicity and potentially selective drug delivery to tumors. The intrinsic radiolabeling through the direct addition of 64Cu to CuNC (64Cu-CuNCs-FC131) synthesis offers high specific activity for sensitive and accurate detection of CXCR4 via FC131-directed targeting in novel triple negative breast cancer (TNBC) patient-derived xenograft mouse models and human TNBC tissues. In summary, this study not only reveals the potential of CXCR4-targeted 64Cu-CuNCs for TNBC imaging in clinical settings, but also provides a useful strategy to design and assess the translational potential of nanoparticles for cancer theranostics.

Functional, Degradable Zwitterionic Polyphosphoesters as Biocompatible Coating Materials for Metal Nanostructures.

A zwitterionic polyphosphoester (zPPE), specifically l-cysteine-functionalized poly(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane (zPBYP), has been developed as a poly(ethylene glycol) (PEG) alternative coating material for gold nanoparticles (AuNPs), the most extensively investigated metal nanoparticulate platform toward molecular imaging, photothermal therapy, and drug delivery applications. Thiol-yne conjugation of cysteine transformed an initial azido-terminated and alkynyl-functionalized PBYP homopolymer into zPBYP, offering hydrolytic degradability, biocompatibility, and versatile reactive moieties for installation of a range of functional groups. Despite minor degradation during purification, zPPEs were able to stabilize AuNPs presumably through multivalent interactions between combinations of the side chain zwitterions (thioether and phosphoester groups of the zPPEs with the AuNPs). 31P NMR studies in D2O revealed ca. 20% hydrolysis of the phosphoester moieties of the repeat units had occurred during the workup and purification by aqueous dialysis at pH 3 over ca. 1 d, as observed by the 31P signal of the phosphotriesters resonating at ca. -0.5 to -1.7 shifting downfield to ca. 1.1 to -0.4 ppm, attributed to transformation to phosphates. Further hydrolysis of side chain and backbone units proceeded to an extent of ca. 75% over the next 2 d in nanopure water (pH 5-6). The NMR degradation results were consistent with the broadening and red-shift of the surface plasmon resonance (SPR) observed by UV-vis spectroscopy of the zPPE-coated AuNPs in water over time. All AuNP formulations in this study, including those with citrate, PEG, and zPPE coatings, exhibited negligible immunotoxicity, as determined by cytokine overexpression in the presence of the nanostructures relative to those in cell culture medium. Notably, the zPPE-coated AuNPs displayed superior antifouling properties, as assessed by the extent of cytokine adsorption relative to both the PEGylated and citrate-coated AuNPs. Taken together, the physicochemical and biological evaluations of zPPE-coated AuNPs in conjunction with PEGylated and citrate-coated analogues indicate the promise of zPPEs as favorable alternatives to PEG coatings, with negligible immunotoxicity, good antifouling performance, and versatile reactive groups that enable the preparation of highly tailored nanomaterials for diverse applications.

Recombinant Gallid herpesvirus 2 with interrupted meq genes confers safe and efficacious protection against virulent field strains.

Gallid herpesvirus 2 (GaHV-2) continuously evolves, which reduces the effectiveness of existing vaccines. To construct new GaHV-2 candidate vaccines, LMS, which is a virulent GaHV-2 field strain isolated from diseased chicken flocks in Southwest China in 2007, was modified such that both copies of its meq oncogene were partially deleted. The resulting virus, i.e., rMSΔmeq, was characterized using PCR and sequencing. To evaluate the safety and protective efficacy of rMSΔmeq, specific pathogen-free (SPF) chickens were inoculated with 2000 plaque forming units (pfu) and 20,000pfu of rMSΔmeq immediately after hatching. All birds grew well during the experimental period, and none of the challenged chickens developed Marek's disease-associated lymphoma. In addition, the rMSΔmeq- and CVI988/Rispens-vaccinated SPF chickens were challenged with 1000 pfu and 5000 pfu of the representative virulent GaHV-2 Md5 strain and 1000 pfu of the variant GaHV-2 strains LCC or LTS. The results showed that the rMSΔmeq strain provided complete protection, which was similar to that provided by the CVI988/Rispens vaccine (protective index (PI) of 95.5) when challenged with a conventional dose of the Md5 strain. However, rMSΔmeq provided a PI of 90.9 when challenged with 5000 pfu of the Md5 strain, which was significantly higher than that provided by the CVI988/Rispens vaccine (54.5). rMSΔmeq provided a PI of 86.4 against LCC, which was equal to that provided by the CVI988/Rispens vaccine (81.8). In addition, rMSΔmeq provided a PI of 100 against LTS, which was significantly higher than that provided by the CVI988/Rispens vaccine (68.2). Altogether, the rMSΔmeq virus provided efficient protection against representative and variant GaHV-2 strains. In conclusion, the rMSΔmeq virus is a safe and effective vaccine candidate for the prevention of Marek's disease and is effective against the Chinese variant GaHV-2 strains.

Co-Infection with Marek's Disease Virus and Reticuloendotheliosis Virus Increases Illness Severity and Reduces Marek's Disease Vaccine Efficacy.

Marek's disease virus (MDV) and reticuloendotheliosis virus (REV) cause Marek's disease (MD) and reticuloendotheliosis (RE), respectively. Co-infection with MDV and REV is common in chickens, causing serious losses to the poultry industry. However, experimental studies of such co-infection are lacking. In this study, Chinese field strains of MDV (ZW/15) and REV (JLR1501) were used as challenge viruses to evaluate the pathogenicity of co-infection and the influence of MD vaccination in chickens. Compared to the MDV-challenged group, the mortality and tumor rates increased significantly by 20.0% (76.7 to 96.7%) and 26.7% (53.3 to 80.0%), in the co-challenged group, respectively. The protective index of the MD vaccines CVI988 and 814 decreased by 33.3 (80.0 to 47.7) and 13.3 (90.0 to 76.7), respectively. These results indicated that MDV and REV co-infection significantly increased disease severity and reduced the vaccine efficacy. The MDV genome load showed no difference in the feather pulps and spleen, and pathogenicity-related MDV gene expression (meq, pp38, vIL-8, and ICP4) in the spleen significantly increased at some time points in the co-challenged group. Clearly, synergistic pathogenicity occurred between MDV and REV, and the protective efficacy of existing MD vaccines was attenuated by co-infection with Chinese field MDV and REV strains.

A Chinese Variant Marek's Disease Virus Strain with Divergence between Virulence and Vaccine Resistance.

Marek's disease (MD) virus (MDV) has been evolving continuously, leading to increasing vaccination failure. Here, the MDV field strain BS/15 was isolated from a severely diseased Chinese chicken flock previously vaccinated with CVI988. To explore the causes of vaccination failure, specific-pathogen free (SPF) chickens vaccinated with CVI988 or 814 and unvaccinated controls were challenged with either BS/15 or the reference strain Md5. Both strains induced MD lesions in unvaccinated chickens with similar mortality rates of 85.7% and 80.0% during the experimental period, respectively. However, unvaccinated chickens inoculated with BS/15 exhibited a higher tumor development rate (64.3% vs. 40.0%), but prolonged survival and diminished immune defects compared to Md5-challenged counterparts. These results suggest that BS/15 and Md5 show a similar virulence but manifest with different pathogenic characteristics. Moreover, the protective indices of CVI988 and 814 were 33.3 and 66.7 for BS/15, and 92.9 and 100 for Md5, respectively, indicating that neither vaccine could provide efficient protection against BS/15. Taken together, these data suggest that MD vaccination failure is probably due to the existence of variant MDV strains with known virulence and unexpected vaccine resistance. Our findings should be helpful for understanding the pathogenicity and evolution of MDV strains prevalent in China.