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Both Klebsiella pneumoniae and Chryseobacterium cause an increasing number of diseases in fish, resulting in great economic losses in aquaculture. In addition, the disease infected with Klebsiella pneumoniae or Chryseobacterium exhibited the similar clinical symptoms in aquatic animals. However, there is no effective means for the simultaneous detection of co-infection and discrimination them for these two pathogens. Here, we developed a duplex polymerase chain reaction (PCR) method based on the outer membrane protein A (ompA) gene of Klebsiella pneumoniae and Chryseobacterium. The specificity and validity of the designed primers were confirmed experimentally using simplex PCR. The expected amplicons for Klebsiella pneumoniae and Chryseobacterium had a size of 663 and 1404 bp, respectively. The optimal condition for duplex PCR were determined to encompass a primer concentration of 0.5 µM and annealing temperature of 57°C. This method was analytical specific with no amplification being observed from the genomic DNA of Escherichia coli, Vibrio harveyi, Pseudomonas plecoglossicida, Aeromonas hydrophila and Acinetobacter johnsonii. The limit of detection was estimated to be 20 fg of genomic DNA for Chryseobacterium and 200 fg for Klebsiella pneumoniae, or 100 colony-forming units (CFU) of bacterial cells in both cases. The duplex PCR was capable of simultaneously amplifying target fragments from genomic DNA extracted from the bacteria and fish liver. For practical validation of the method, 20 diseased fish were collected from farms, among which 4 samples were PCR-positive for Klebsiella pneumoniae and Chryseobacterium. The duplex PCR method developed here is time-saving, specific, convenient, and may prove to be an invaluable tool for molecular detection and epidemiological investigation of Klebsiella pneumoniae and Chryseobacterium in the field of aquaculture.
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Chryseobacterium , Enfermedades de los Peces , Klebsiella pneumoniae , Animales , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/genética , Chryseobacterium/aislamiento & purificación , Chryseobacterium/genética , Enfermedades de los Peces/microbiología , Enfermedades de los Peces/diagnóstico , Perciformes/microbiología , Infecciones por Klebsiella/veterinaria , Infecciones por Klebsiella/diagnóstico , Infecciones por Klebsiella/microbiología , Infecciones por Flavobacteriaceae/veterinaria , Infecciones por Flavobacteriaceae/microbiología , Infecciones por Flavobacteriaceae/diagnóstico , Acuicultura , ADN Bacteriano/aislamiento & purificación , ADN Bacteriano/genética , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Reacción en Cadena de la Polimerasa Multiplex/veterinaria , Reacción en Cadena de la Polimerasa Multiplex/métodos , Cartilla de ADNRESUMEN
Despite prolonged surveillance and interventions, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses continue to pose a severe global health burden. Thus, we developed a chimpanzee adenovirus-based combination vaccine, AdC68-HATRBD, with dual specificity against SARS-CoV-2 and influenza virus. When used as a standalone vaccine, intranasal immunization with AdC68-HATRBD induced comprehensive and potent immune responses consisting of immunoglobin (Ig) G, mucosal IgA, neutralizing antibodies, and memory T cells, which protected the mice from BA.5.2 and pandemic H1N1 infections. When used as a heterologous booster, AdC68-HATRBD markedly improved the protective immune response of the licensed SARS-CoV-2 or influenza vaccine. Therefore, whether administered intranasally as a standalone or booster vaccine, this combination vaccine is a valuable strategy to enhance the overall vaccine efficacy by inducing robust systemic and mucosal immune responses, thereby conferring dual lines of immunological defenses for these two viruses.
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Marine natural gas hydrate (NGH) is a promising substitutive low-carbon energy resource, whereas NGH-production induced geoengineering concerns remain challenging. Advanced forecast of possible geoengineering risks is the fundamental for eco-friendly NGH exploitation. Reservoir creep deformation is an early symptom of the geoengineering risks. However, whether the creep deformation behaviors of the NGH-bearing strata is predictable remains controversial. In this study, a series of multi-step loading creep test are conducted for sandy gas hydrate bearing sediment (GHBS) samples, during which the ultrasonic responses are recorded simultaneously. The acoustic velocity, compression-to-shear velocity ratio, Poission's ratio, main frequency, and main frequency amplitude are used to characterize creep failures of the GHBS for the first time. Combining analyses of the creep behaviors and acoustic responses yield the following conclusions. Firstly, the long-term strength derived from creeping test is 0.45-0.60 times of the shear strength derived from triaxial shearing. Ignoring the creep effect might underestimate the scale and intensity of possible geoengineering risks during long-term NGH exploitation. Secondly, the acoustic velocity increases gently and then decreases continuously during creeping. Once the accelerated creep appears, the acoustic velocity plummets significantly, together with a sudden decrease in the compression-to-shear velocity ratio, and fluctuations in the main frequency and its amplitude. Furthermore, the main frequency and its amplitude shall fluctuate abruptly prior to the emergence of the accelerated creep. Therefore, we anticipate that the combination of abnormal fluctuations of main frequency and its amplitude can be used as early-warning indicators for possible creep failure of the GHBS. The results might have great significance for in-situ detection and prediction of possible reservoir failure during long-term NGH exploitation.
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It is of great significance to study the mechanical behavior and permeability properties of hydrate-bearing sediments for a safe, efficient, and sustainable exploitation of hydrate. However, most of the studies conducted so far have focused only on a single stress field or seepage field, which is detached from practical engineering. In this paper, a new integrated experimental system (IES) was proposed, which realizes the coupling study of stress and seepage. The main body of IES is a triaxial subsystem and a seepage subsystem. The triaxial subsystem can realize in situ synthesis and triaxial shear of hydrate-bearing sediments (HBS). Stable seepage can be effectively formed using a constant pressure infusion pump and a back pressure valve. A series of shear-seepage coupling tests were carried out to verify the effectiveness of the IES and explore the stress-seepage coupling characteristics of HBS. The results show that stress has a significant influence on permeability, and its essence is the stress compression on the seepage channel. The stress-strain relationship, volume response, and permeability are related to each other. The permeability will be affected by the coupling of hydrate saturation (pore plugging), effective confining pressure (pore compression), and shear (fracture generation).
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IMPORTANCE: The development of broad-spectrum SARS-CoV-2 vaccines will reduce the global economic and public health stress from the COVID-19 pandemic. The use of conserved T-cell epitopes in combination with spike antigen that induce humoral and cellular immune responses simultaneously may be a promising strategy to further enhance the broad spectrum of COVID-19 vaccine candidates. Moreover, this research suggests that the combined vaccination strategies have the ability to induce both effective systemic and mucosal immunity, which may represent promising strategies for maximizing the protective efficacy of respiratory virus vaccines.
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Vacunas contra la COVID-19 , COVID-19 , Vacunas Combinadas , Humanos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , Inmunidad Celular , Inmunización , Pandemias/prevención & control , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , VacunaciónRESUMEN
As Klebsiella pneumoniae (KP) has acquired high levels of resistance to multiple antibiotics, it is considered a worldwide pathogen of concern, and substitutes for traditional antibiotics are urgently needed. 3-Phenyllactic acid (PLA) has been reported to have antimicrobial activity against food-borne bacteria. However, there was no experiment evidence for the exact antibacterial effect and mechanism of PLA kills pathogenic KP. In this study, the Oxford cup method indicated that PLA is effective to KP with a minimum inhibitory concentration of 2.5 mg/mL. Furthermore, PLA inhibited the growth and biofilm formation of in a time- and concentration-dependent manner. In vivo, PLA could significantly increase the survival rate of infected mice and reduce the pathological tissue damage. The antibacterial mode of PLA against KP was further explored. Firstly, scanning electron microscopy illustrated the disruption of cellular ultrastructure caused by PLA. Secondly, measurement of leaked alkaline phosphatase demonstrated that PLA disrupted the cell wall integrity of KP and flow cytometry analysis with propidium iodide staining suggested that PLA damaged the cell membrane integrity. Finally, the results of fluorescence spectroscopy and agarose gel electrophoresis demonstrated that PLA bound to genomic DNA and initiated its degradation. The anti-KP mode of action of PLA was attributed to the destruction of the cell wall, membrane, and genomic DNA binding. These findings suggest that PLA has great potential applications as antibiotic substitutes in feed additives against KP infection in animals.
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Infecciones por Klebsiella , Klebsiella pneumoniae , Animales , Ratones , Klebsiella pneumoniae/genética , Membrana Celular , Antibacterianos/farmacología , Pared Celular , ADN/farmacología , Genómica , Poliésteres , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiologíaRESUMEN
Arthritogenic alphaviruses, including chikungunya virus (CHIKV), preferentially target joint tissues and cause chronic rheumatic disease that adversely impacts the quality of life of patients. Viruses enter target cells via interaction with cell surface receptor(s), which determine the viral tissue tropism and pathogenesis. Although MXRA8 is a recently identified receptor for several clinically relevant arthritogenic alphaviruses, its detailed role in the cell entry process has not been fully explored. We found that in addition to its localization on the plasma membrane, MXRA8 is present in acidic organelles, endosomes, and lysosomes. Moreover, MXRA8 is internalized into cells without a requirement for its transmembrane and cytoplasmic domains. Confocal microscopy and live cell imaging revealed that MXRA8 interacts with CHIKV at the cell surface and then enters cells along with CHIKV particles. At the moment of membrane fusion in the endosomes, many viral particles are still colocalized with MXRA8. These findings provide insight as to how MXRA8 functions in alphavirus internalization and suggest possible targets for antiviral development. IMPORTANCE The globally distributed arthritogenic alphaviruses have infected millions of humans and induce rheumatic disease, such as severe polyarthralgia/polyarthritis, for weeks to years. Alphaviruses infect target cells through receptor(s) followed by clathrin-mediated endocytosis. MXRA8 was recently identified as an entry receptor that shapes the tropism and pathogenesis for multiple arthritogenic alphaviruses, including chikungunya virus (CHIKV). Nonetheless, the exact functions of MXRA8 during the process of viral cell entry remain undetermined. Here, we have provided compelling evidence for MXRA8 as a bona fide entry receptor that mediates the uptake of alphavirus virions. Small molecules that disrupt MXRA8-dependent binding of alphaviruses or internalization steps could serve as a platform for unique classes of antiviral drugs.
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Fiebre Chikungunya , Virus Chikungunya , Enfermedades Reumáticas , Humanos , Virus Chikungunya/fisiología , Internalización del Virus , Fusión de Membrana , Calidad de VidaRESUMEN
To evaluate the flavor characteristics of Chinese bayberry alcoholic beverages, fermented bayberry wine (FBW) and integrated bayberry wine (IBW) were investigated for their volatile and soluble profiles using HS-SPME GC-MS and UHPLC Q-TOF and were analyzed with multidimensional statistical analysis, including PCA and OPLS-DA. The volatile compounds 1-pentanol, ß-caryophyllene and isopentanol were only detected in IBW. ß-caryophyllene, the key flavor component of bayberry, was found to be the most abundant volatile compound in IBW (25.89%) and was 3.73 times more abundant in IBW than in FBW. The levels of ethyl octanoate, ethyl nonanoate, and ethyl decanoate were also several times higher in IBW than in FBW. These compounds contributed to the strong bayberry aroma and better fruity flavor of IBW. On the other hand, high levels of ethyl acetate and octanoic acid in FBW, representing pineapple/overripe or sweat odor, were key contributors to the fermented flavor of FBW. Soluble sugars, such as sucrose, D-glucose, and D-tagatose, as well as amino acids, such as L-glutamate and L-aspartate, had much higher levels in IBW. The anthocyanin pigment cyanidin 3-glucoside, which generates red color, was also higher in IBW. On the other hand, most of the differentially expressed alcohols, acids, amino acids, purines/pyrimidines and esters were present in higher concentrations in FBW compared to IBW. This demonstrated that IBW has a much sweeter and more savory taste as well as a better color generated by more anthocyanins, while FBW presents a more acidic and drier taste as well as a complex formation of alcohols and esters. The study also prompts the need for further research on the flavor profiles of IBW and its potential application and market value.
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Natural gas hydrate (NGH) exploitation is severely restricted by geotechnical problems. Deformation behaviors of the hydrate-bearing strata (HBS) control the occurrence and evolution of geotechnical problems during extracting natural gas from HBS. In this paper, a novel approach named Ladetes is introduced to evaluate the lateral deformation behaviors of the near-wellbore and fracture-filling regions of the HBS. The pressuremeter test and the flat dilatometer test are designed to simulate the inner boundaries of an NGH-producing well and an artificial stimulation fracture for the first time. The device can realize the in situ hydrate formation prior to the experiment and axial loading application throughout the experiment. Both the strain control mode and the stress control mode can be achieved to estimate the deformation characteristics of HBS under different downhole conditions. Prime experiments proved their adaptability and reliability. The Ladetes provides an effective and alternative way of obtaining geotechnical parameters for HBS.
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d-Phenyllactic acid, is a versatile organic acid with wide application prospects in the food, pharmaceutical and material industries. Wild-type lactate dehydrogenase LrLDH from Lactobacillus rossiae exhibits a high catalytic performance in the production of d-phenyllactic acid from phenylpyruvic acid or sodium phenylpyruvate, but its industrial application is hampered by poor thermostability. Here, computer aided rational design was applied to improve the thermostability of LrLDH. By using HotSpot Wizard 3.0, five hotspot residues (N218, L237, T247, D249 and S301) were identified, after which site-saturation mutagenesis and combined mutagenesis were performed. The double mutant D249A/T247I was screen out as the best variant, with optimum temperature, t 1/2, and T 10 50 that were 12 °C, 17.96 min and 19 °C higher than that of wild-type LrLDH, respectively. At the same time, the k cat/K m of D249A/T247I was 1.47 s-1 mM-1, which was 3.4 times higher than that of the wild-type enzyme. Thus rational design was successfully applied to simultaneously improve the thermostability and catalytic activity of LrLDH to a significant extent. The results of molecular dynamics simulations and molecular structure analysis could explain the mechanisms for the improved performance of the double mutant. This study shows that computer-aided rational design can greatly improve the thermostability of d-lactate dehydrogenase, offering a reference for the modification of other enzymes.
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Frequent outbreaks of coronaviruses underscore the need for antivirals and vaccines that can counter a broad range of coronavirus types. We isolated a human antibody named 76E1 from a COVID-19 convalescent patient, and report that it has broad-range neutralizing activity against multiple α- and ß-coronaviruses, including the SARS-CoV-2 variants. 76E1 also binds its epitope in peptides from γ- and δ-coronaviruses. 76E1 cross-protects against SARS-CoV-2 and HCoV-OC43 infection in both prophylactic and therapeutic murine animal models. Structural and functional studies revealed that 76E1 targets a unique epitope within the spike protein that comprises the highly conserved S2' site and the fusion peptide. The epitope that 76E1 binds is partially buried in the structure of the SARS-CoV-2 spike trimer in the prefusion state, but is exposed when the spike protein binds to ACE2. This observation suggests that 76E1 binds to the epitope at an intermediate state of the spike trimer during the transition from the prefusion to the postfusion state, thereby blocking membrane fusion and viral entry. We hope that the identification of this crucial epitope, which can be recognized by 76E1, will guide epitope-based design of next-generation pan-coronavirus vaccines and antivirals.
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COVID-19 , SARS-CoV-2 , Animales , Antivirales , Epítopos , Humanos , Inmunoglobulinas , Ratones , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
There is a potential risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread through human contact with seafood and the inanimate materials contaminated by the virus. In this study, we examined the stability of the virus in artificial seawater (ASW) and on the surface of selected materials. SARS-CoV-2 (3.75 log10 TCID50 ) in ASW at 22â maintained infectious about 3 days and at 4â the virus survived more than 7 days. It should be noticed that viable virus at high titer (5.50 log10 TCID50 ) may survive more than 20 days in ASW at 4â and for 7 days at 22â. SARS-CoV-2 on stainless steel and plastic bag maintained infectious for 3 days, and on nonwoven fabric for 1 day at 22â. In addition, the virus remained infectious for 9 days on stainless steel and non-woven fabric, and on plastic bag for 12 days at 4â. It is important to highlight the role of inanimate material surfaces as a source of infection and the necessity for surface decontamination and disinfection.
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COVID-19 , SARS-CoV-2 , Humanos , Plásticos , Agua de Mar , Acero InoxidableRESUMEN
The effectiveness of SARS-CoV-2 vaccines and therapeutic antibodies have been limited by the continuous emergence of viral variants and by the restricted diffusion of antibodies from circulation into the sites of respiratory virus infection. Here, we report the identification of two highly conserved regions on the Omicron variant receptor-binding domain recognized by broadly neutralizing antibodies. Furthermore, we generated a bispecific single-domain antibody that was able to simultaneously and synergistically bind these two regions on a single Omicron variant receptor-binding domain as revealed by cryo-EM structures. We demonstrated that this bispecific antibody can be effectively delivered to lung via inhalation administration and exhibits exquisite neutralization breadth and therapeutic efficacy in mouse models of SARS-CoV-2 infections. Importantly, this study also deciphered an uncommon and highly conserved cryptic epitope within the spike trimeric interface that may have implications for the design of broadly protective SARS-CoV-2 vaccines and therapeutics.
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Vacunas contra la COVID-19 , Anticuerpos de Dominio Único , Administración por Inhalación , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19 , Vacunas contra la COVID-19/administración & dosificación , Modelos Animales de Enfermedad , Humanos , Ratones , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/químicaRESUMEN
There are various challenges for the mucosal delivery of drug, which is largely attributed to the absence of effective drug carriers that can make delivery to mucosal sites. In the present study, we aimed to synthesize bifunctional mucoadhesive nanoparticles (NPs) that could be used for mucosal delivery. N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (M-N-2-HACC) was modified with D-mannose, and N-acetyl-L-cysteine (NAC) was immobilized on the carboxymethyl chitosan (N-CMCS). The electrostatic interaction between the two substances was used to produce mannose-modified thiolated chitosan NPs (M-N-2-HACC/N-CMCS NPs). The NPs showed a particle size of 196.72 ± 0.45 nm and zeta potential of 17.12 ± 0.50 mV. Moreover, it demonstrated high hydrophilicity, enduring drug release, stability, safety, and mucosal adhesion, which contributed to the effectiveness of mucosal administration. Additionally, the NPs could be instantly absorbed by macrophages. Collectively, these results suggested that M-N-2-HACC/N-CMCS NPs could be used as a promising candidate for mucosal delivery.
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Quitosano/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Manosa/química , Nanopartículas/química , Acetilcisteína/química , Administración a través de la Mucosa , Fenómenos Químicos , Quitosano/análogos & derivados , Portadores de Fármacos/administración & dosificación , Liberación de Fármacos , Células HEK293 , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Macrófagos/efectos de los fármacos , Mucinas/metabolismo , Tamaño de la PartículaRESUMEN
In recent years, Klebsiella pneumoniae (KP) has caused disease outbreaks in different animals, resulting in serious economic losses and biosafety concerns. Considering the broad antibiotic resistance of KP, vaccines are the most effective tools against infection. However, there is still no KP vaccine available in the veterinary field. Our results indicate that the highly conserved outer membrane phosphoporin (PhoE) of KP is immunogenic in mice and elicits high titers of antibodies that were shown to be specific for PhoE by immunoblotting. Immunization with PhoE also induced robust cell-mediated immunity and elicited the secretion of high levels of IFN-γ and IL-4, suggesting the induction of mixed Th1 and Th2 responses. Sera from PhoE-immunized mice induced significantly higher complement-mediated lysis of KP cells than did sera from the PBS control mice. Finally, mice immunized with PhoE were significantly protected against KP challenge, with better survival and a reduced visceral bacterial load. Our data underscore the great potential of PhoE as a novel candidate antigen for a vaccine against KP infection.
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Anticuerpos Antibacterianos , Proteínas de la Membrana Bacteriana Externa , Vacunas Bacterianas , Klebsiella pneumoniae , Porinas , Animales , Anticuerpos Antibacterianos/sangre , Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Inmunización/veterinaria , Ratones , Ratones Endogámicos BALB C , Porinas/inmunología , Vacunación/veterinariaRESUMEN
Host cellular receptors play key roles in the determination of virus tropism and pathogenesis. However, little is known about SARS-CoV-2 host receptors with the exception of ACE2. Furthermore, ACE2 alone cannot explain the multi-organ tropism of SARS-CoV-2 nor the clinical differences between SARS-CoV-2 and SARS-CoV, suggesting the involvement of other receptor(s). Here, we performed genomic receptor profiling to screen 5054 human membrane proteins individually for interaction with the SARS-CoV-2 capsid spike (S) protein. Twelve proteins, including ACE2, ASGR1, and KREMEN1, were identified with diverse S-binding affinities and patterns. ASGR1 or KREMEN1 is sufficient for the entry of SARS-CoV-2 but not SARS-CoV in vitro and in vivo. SARS-CoV-2 utilizes distinct ACE2/ASGR1/KREMEN1 (ASK) receptor combinations to enter different cell types, and the expression of ASK together displays a markedly stronger correlation with virus susceptibility than that of any individual receptor at both the cell and tissue levels. The cocktail of ASK-related neutralizing antibodies provides the most substantial blockage of SARS-CoV-2 infection in human lung organoids when compared to individual antibodies. Our study revealed an interacting host receptome of SARS-CoV-2, and identified ASGR1 and KREMEN1 as alternative functional receptors that play essential roles in ACE2-independent virus entry, providing insight into SARS-CoV-2 tropism and pathogenesis, as well as a community resource and potential therapeutic strategies for further COVID-19 investigations.
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COVID-19 , Glicoproteína de la Espiga del Coronavirus , Receptor de Asialoglicoproteína , Recursos Comunitarios , Humanos , Proteínas de la Membrana , Unión Proteica , Receptores Virales/metabolismo , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/metabolismo , Internalización del VirusRESUMEN
The current COVID-19 pandemic has heavily burdened the global public health system and may keep simmering for years. The frequent emergence of immune escape variants have spurred the search for prophylactic vaccines and therapeutic antibodies that confer broad protection against SARS-CoV-2 variants. Here we show that the bivalency of an affinity maturated fully human single-domain antibody (n3113.1-Fc) exhibits exquisite neutralizing potency against SARS-CoV-2 pseudovirus, and confers effective prophylactic and therapeutic protection against authentic SARS-CoV-2 in the host cell receptor angiotensin-converting enzyme 2 (ACE2) humanized mice. The crystal structure of n3113 in complex with the receptor-binding domain (RBD) of SARS-CoV-2, combined with the cryo-EM structures of n3113 and spike ecto-domain, reveals that n3113 binds to the side surface of up-state RBD with no competition with ACE2. The binding of n3113 to this novel epitope stabilizes spike in up-state conformations but inhibits SARS-CoV-2 S mediated membrane fusion, expanding our recognition of neutralization by antibodies against SARS-CoV-2. Binding assay and pseudovirus neutralization assay show no evasion of recently prevalent SARS-CoV-2 lineages, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2) for n3113.1-Fc with Y58L mutation, demonstrating the potential of n3113.1-Fc (Y58L) as a promising candidate for clinical development to treat COVID-19.
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Enzima Convertidora de Angiotensina 2/química , Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/química , COVID-19 , SARS-CoV-2/química , Anticuerpos de Cadena Única/química , Enzima Convertidora de Angiotensina 2/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/uso terapéutico , Cristalografía por Rayos X , Epítopos/química , Epítopos/inmunología , Humanos , Ratones , SARS-CoV-2/inmunología , Anticuerpos de Cadena Única/inmunología , Anticuerpos de Cadena Única/uso terapéuticoRESUMEN
Porcine parvovirus (PPV) is the most important infectious agent causing infertility in pigs, which can be prevented by routine vaccination. Successful vaccination depends on the association with potent adjuvants that can enhance the immunogenicity of antigen and activate the immune system. Polysaccharide adjuvant has low toxicity and high safety, and they can enhance the humoral, cellular and mucosal immune responses. In the present study, we prepared the VP2 protein subunit vaccine against PPV (PPV/VP2/N-2-HACC) using water-soluble N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) as the vaccine adjuvant, and the ability of the PPV/VP2/N-2-HACC to induce immune responses and protect sows from PPV infection was evaluated. In vivo immunization showed that the sows immunized with the PPV/VP2/N-2-HACC by intramuscular injection produced higher HI antibody levels and long-term immune protection compared with the other groups, while the subunit vaccine did not stimulate the proliferation of CD4+ and CD8+ T lymphocytes to trigger the secretion of higher levels of IL-2, IL-4, IFN-α, IFN-ß, and IFN-γ, indicating that the PPV/VP2/N-2-HACC mainly induced humoral immunity rather than cellular immunity. PPV was not detected in the viscera of the sows immunized with the PPV/VP2/N-2-HACC, and the protective efficacy was 100%. Collectively, our findings suggested that the N-2-HACC was a potential candidate adjuvant, and the PPV/VP2/N-2-HACC had immense application value for the control of PPV.
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BACKGROUND: The physiologic regenerative capacity of cartilage is severely limited. Current studies on the repair of osteochondral defects (OCDs) have mainly focused on the regeneration of cartilage tissues. The antler cartilage is a unique regenerative cartilage that has the potential for cartilage repair. METHODS: Antler decellularized cartilage-derived matrix scaffolds (adCDMs) were prepared by combining freezing-thawing and enzymatic degradation. Their DNA, glycosaminoglycans (GAGs), and collagen content were then detected. Biosafety and biocompatibility were evaluated by pyrogen detection, hemolysis analysis, cytotoxicity evaluation, and subcutaneous implantation experiments. adCDMs were implanted into rabbit articular cartilage defects for 2 months to evaluate their therapeutic effects. RESULTS: AdCDMs were observed to be rich in collagen and GAGs and devoid of cells. AdCDMs were also determined to have good biosafety and biocompatibility. Both four- and eight-week treatments of OCDs showed a flat and smooth surface of the healing cartilage at the adCDMs filled site. The international cartilage repair society scores (ICRS) of adCDMs were significantly higher than those of controls (porcine dCDMs and normal saline) (p < 0.05). The repaired tissue in the adCDM group was fibrotic with high collagen, specifically, type II collagen. CONCLUSIONS: We concluded that adCDMs could achieve excellent cartilage regeneration repair in a rabbit knee OCDs model. Our study stresses the importance and benefits of adCDMs in bone formation and overall anatomical reconstitution, and it provides a novel source for developing cartilage-regenerating repair materials.