RESUMEN
Developing an effective Staphylococcus aureus (S. aureus) vaccine has been a challenging endeavor, as demonstrated by numerous failed clinical trials over the years. In this study, we formulated a vaccine containing a highly conserved moonlighting protein, the pyruvate dehydrogenase complex E2 subunit (PDHC), and showed that it induced strong protective immunity against epidemiologically relevant staphylococcal strains in various murine disease models. While antibody responses contributed to bacterial control, they were not essential for protective immunity in the bloodstream infection model. Conversely, vaccine-induced systemic immunity relied on γδ T cells. It has been suggested that prior S. aureus exposure may contribute to the reduction of vaccine efficacy. However, PDHC-induced protective immunity still facilitated bacterial clearance in mice previously exposed to S. aureus. Collectively, our findings indicate that PDHC is a promising serotype-independent vaccine candidate effective against both methicillin-sensitive and methicillin-resistant S. aureus isolates.
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Infecciones Estafilocócicas , Vacunas Estafilocócicas , Staphylococcus aureus , Animales , Infecciones Estafilocócicas/prevención & control , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/microbiología , Ratones , Staphylococcus aureus/inmunología , Staphylococcus aureus/enzimología , Vacunas Estafilocócicas/inmunología , Complejo Piruvato Deshidrogenasa/metabolismo , Complejo Piruvato Deshidrogenasa/inmunología , Femenino , Anticuerpos Antibacterianos/inmunología , Modelos Animales de Enfermedad , Humanos , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Ratones Endogámicos C57BL , Staphylococcus aureus Resistente a Meticilina/inmunología , Piruvato Deshidrogenasa (Lipoamida)/inmunología , Piruvato Deshidrogenasa (Lipoamida)/metabolismo , Piruvato Deshidrogenasa (Lipoamida)/genéticaRESUMEN
Manure is one of the main sources of heavy metal (HM) pollution on farmlands. It has become the focus of global ecological research because of its potential threat to human health and the sustainability of food systems. Soil pH and organic matter are improved by manure and play pivotal roles in determining soil HM behavior. Geochemical modeling has been widely used to assess and predict the behavior of soil HMs; however, there remains a research gap in manure applications. In this study, a geochemical model (LeachXS) coupled with a pH-dependent leaching test with continuously simulations over a broad pH range was used to determine the effects and pollution risks of pig or cattle manure separate application on soil HMs distribution. Both pig and cattle manure applications led to soil pH reduction in alkaline soils and increased organic matter content. Pig manure application resulted in a potential 90.5-156.0â¯% increase in soil HM content. Cattle manure did not cause significant HM contamination. The leaching trend of soil HMs across treatments exhibited a V-shaped change, with the lowest concentration at pH = 7, gradually increasing toward strong acids and bases. The dissolved organic matter-bound HM content directly increased the HM availability, especially for Cu (up to 8.4â¯%) after pig manure application. However, more HMs (Cr, Cu, Zn, Ni) were in the particulate organic matter-bound state than in other solid phases (e.g., Fe-Al(hydr) oxides, clay minerals), which inhibited the HMs leaching by more than 19.3â¯% after cattle manure application. Despite these variations, high HM concentrations introduced by pig manure raised the soil contamination risk, potentially exceeding 40 times at pH ±1. When manure is returned to the field, reducing its HM content and mitigating possible pollution is necessary to realize the healthy and sustainable development of circular agriculture.
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Estiércol , Metales Pesados , Contaminantes del Suelo , Suelo , Estiércol/análisis , Contaminantes del Suelo/análisis , Metales Pesados/análisis , Animales , Bovinos , Suelo/química , Porcinos , Concentración de Iones de Hidrógeno , Monitoreo del AmbienteRESUMEN
Under the twin pressures of global food security and dualcarbon strategies, improving farm eco-efficiency is critical for achieving China's goal of a 50 Pg increase in grain production, meeting the ambitious climate mitigation targets set by the Paris Agreement, and meeting seven of the seventeen Sustainable Development Goals (SDGs) set by the United Nations. However, there is limited research on eco-efficiency measures supported by localised fine-scale data and coupling mechanisms for the structure, production process, efficiency improvement, and carbon reduction synergies of integrated farming systems in China. This study used the Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methods to assess eco-efficiency at the farm level in northern China, included in the National Coupling Crop and Livestock Production Pilot Programs, to improve the eco-efficiency of farms to achieve increased production and emission reductions. The results showed that the overall eco-efficiency of farms was in the lower-middle range, with only 20.18 % of the farms having a technical efficiency exceeding 1. Problems included a backward level of pure technical efficiency and a return to scale. Non-integrated farms have the lowest profitability (41.33 %) and the highest carbon emission intensity of 3.03 kg CO2eq/USD. The global warming potential impact of non-integrated farms optimization could be reduced by 25 Pg CO2eq. Implementing the integrated farming mode has a significant advantage in reducing carbon emissions and improving productivity. Overall, farm fodder optimization can be increased by up to 42.41 %. Simultaneously, farms with sufficient farmland are more likely to realise a highly integrated business mode for crop cultivation and livestock breeding. Therefore, constructing a new type of green integrated farming system will help farms achieve increased production and emission reductions, promote the development of sustainable agriculture, and provide a Chinese model for the realisation of global SDGs.
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Agricultura , Ganado , Animales , Agricultura/métodos , Granjas , China , Carbono , Estadios del Ciclo de VidaRESUMEN
The rapid diagnosis of respiratory virus infection through breath and blow remains challenging. Here we develop a wireless, battery-free, multifunctional pathogenic infection diagnosis system (PIDS) for diagnosing SARS-CoV-2 infection and symptom severity by blow and breath within 110 s and 350 s, respectively. The accuracies reach to 100% and 92% for evaluating the infection and symptom severity of 42 participants, respectively. PIDS realizes simultaneous gaseous sample collection, biomarker identification, abnormal physical signs recording and machine learning analysis. We transform PIDS into other miniaturized wearable or portable electronic platforms that may widen the diagnostic modes at home, outdoors and public places. Collectively, we demonstrate a general-purpose technology for rapidly diagnosing respiratory pathogenic infection by breath and blow, alleviating the technical bottleneck of saliva and nasopharyngeal secretions. PIDS may serve as a complementary diagnostic tool for other point-of-care techniques and guide the symptomatic treatment of viral infections.
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Líquidos Corporales , COVID-19 , Humanos , SARS-CoV-2 , COVID-19/diagnóstico , Manejo de Especímenes , SalivaRESUMEN
Ecological restoration practices have been widely adopted to increase soil carbon stocks by improving soil organic carbon (SOC). However, the effects of these practices on the other important soil carbon component, soil inorganic carbon (SIC), remain unclear. To address this, a meta-analysis based on 45 publications and 37 sites was conducted to quantitatively assess the dynamic changes in SIC stocks due to typical restoration practices, including conversion of cropland to forest (C-F), cropland to grassland (C-G), desert to cropland (D-C), conservation agriculture (CA), and desert to forest (D-F). Results showed that, among the restoration practices increasing the SOC stocks, the SIC stocks decreased after the C-F (-34.7%) and C-G (-15.8%) conversions and CA (-6.8%), but increased after the conversion of D-C (2.6%) and D-F (46.9%). Additionally, in terms of recovery duration, the negative effect of C-G on SIC stocks may vanish with increased recovery duration, whereas SIC stocks showed a prominent increase initially after CA and then decreased over time; the response to D-F conversion of SIC stocks remained consistently positive over time. Furthermore, the non-synergistic changes with SIC and SOC could be due to variations in edaphic factors, while the effects edaphic factors on SIC stocks were different under various ecological restoration practices. Among all the impact factors, mean annual temperature, initial SIC stocks, and types of ecological restoration practice, were the most crucial factors explaining the variation in SIC stocks with ecological restoration. Collectively, the results highlight that the change in SIC stocks is asynchronous with the increase in SOC stocks in space and time after ecological restoration, further indicating that changes in SIC stocks should be paid more attention when assessing and predicting carbon sequestration following various ecological restoration practices.
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Carbono , Suelo , Agricultura/métodos , Bosques , Secuestro de CarbonoRESUMEN
Freshwater resources are becoming increasingly scarce in coastal areas, limiting crop productivity in coastal farmlands. Although the characteristic of crop water use is an important factor for water conservation in coastal farmlands, it has not been studied extensively. This study aimed to depict the water use process of soil-plant systems under saline stress in coastal ecosystems and optimize water management. An intensive observation experiment was performed within China's Yellow River Delta to identify the water use processes and crop coefficients (KC) and also quantify the impacts of salt stress on crop water use. The results show that shallow groundwater did not contribute to soil water in the whole rotation; KC values for wheat-maize, wheat-sorghum, and wheat-soybean rotation systems were 45.0, 58.4, and 57% less, respectively, than the FAO values. The water use efficiency of the maize (8.70) and sorghum (9.00) in coastal farmlands was higher than that of the soybean (4.37). By identifying the critical periods of water and salt stress, this paper provides suggestions for water-saving and salinity control in coastal farmlands. Our findings can inform the sustainable development of coastal farmlands and provide new insights to cope with aspects of the global food crisis.
RESUMEN
Current COVID-19 vaccines are highly effective against symptomatic disease, but repeated booster doses using vaccines based on the ancestral strain offer limited additional protection against SARS-CoV-2 variants of concern (VOCs). To address this, we used antigenic distance to in silico select optimized booster vaccine seed strains effective against both current and future VOCs. Our model suggests that a SARS-CoV-1-based booster vaccine has the potential to cover a broader range of VOCs. Candidate vaccines including the spike protein from ancestral SARS-CoV-2, Delta, Omicron (BA.1), SARS-CoV-1, or MERS-CoV were experimentally evaluated in mice following two doses of the BNT162b2 vaccine. The SARS-CoV-1-based booster vaccine outperformed other candidates in terms of neutralizing antibody breadth and duration, as well as protective activity against Omicron (BA.2) challenge. This study suggests a unique strategy for selecting booster vaccines based on antigenic distance, which may be useful in designing future booster vaccines as new SARS-CoV-2 variants emerge.
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COVID-19 , Animales , Humanos , Ratones , COVID-19/prevención & control , SARS-CoV-2 , Vacunas contra la COVID-19 , Vacuna BNT162 , Anticuerpos Neutralizantes , Anticuerpos AntiviralesRESUMEN
The overall success of worldwide mass vaccination in limiting the negative effect of the COVID-19 pandemics is inevitable, however, recent SARS-CoV-2 variants of concern, especially Omicron and its sub-lineages, efficiently evade humoral immunity mounted upon vaccination or previous infection. Thus, it is an important question whether these variants, or vaccines against them, induce anti-viral cellular immunity. Here we show that the mRNA vaccine BNT162b2 induces robust protective immunity in K18-hACE2 transgenic B-cell deficient (µMT) mice. We further demonstrate that the protection is attributed to cellular immunity depending on robust IFN-γ production. Viral challenge with SARS-CoV-2 Omicron BA.1 and BA.5.2 sub-variants induce boosted cellular responses in vaccinated µMT mice, which highlights the significance of cellular immunity against the ever-emerging SARS-CoV-2 variants evading antibody-mediated immunity. Our work, by providing evidence that BNT162b2 can induce significant protective immunity in mice that are unable to produce antibodies, thus highlights the importance of cellular immunity in the protection against SARS-CoV-2.
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Vacunas contra la COVID-19 , COVID-19 , Inmunidad Celular , Animales , Humanos , Ratones , Anticuerpos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Vacuna BNT162 , COVID-19/prevención & control , Interferón gamma , SARS-CoV-2 , Vacunas contra la COVID-19/inmunologíaRESUMEN
Sweet sorghum is a high-yield crop with strong resistance, which has the potential to support the development of the forage farming industry in China where vast salt-affected lands are potentially arable. Nutrient management is imperative for sweet sorghum growing on salt-affected lands. Although nitrogen (N) synthetic fertilizers have long been recognized as a key factor for increasing crop yields, their effects on sweet sorghum cultivation are under debate. Consequently, this study integrated the current available observations of yield (n = 255) and partial factor productivity of nitrogen (NPFP, n = 242) of sweet sorghum in salt-affected lands, which included both inland (n = 189) and coastal (n = 66) areas. We quantitatively analyzed the effects of climatic, soil properties and management measures on biomass yield and NPFP of sweet sorghum, comparing the differences between inland and coastal salt-affected lands. We found that average biomass yield and NPFP of sweet sorghum in coastal areas were 19,082.48 ± 8262.75 kg/ha and 107.29 ± 51.44 kg/kg respectively, both significantly lower than that in inland areas (p < 0.05). The N application rate did not have significant promoting effect on the biomass yield of sweet sorghum in inland salt-affected areas (p > 0.05), whereas in coastal salt-affected areas, N application significantly increased the biomass yield of sweet sorghum. Increasing soil organic matter content could promote NPFP in inland areas. The recommended N application rate for inland salt-affected and coastal salt-affected areas were 100 kg/ha and 150 kg/ha respectively. The results indicate that it is crucial to apply nutrient management measures based on the local climatic and soil conditions, since the causes of salinity differ in coastal and inland salt-affected lands. More systematic field studies are required in the future to optimize the management of water and nutrients for sweet sorghum planting in salt-affected lands.
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Sorghum , Suelo , Cloruro de Sodio/farmacología , Nitrógeno , ChinaRESUMEN
The ongoing coronavirus disease 2019 pandemic has raised concerns about the risk of re-infection. Non-neutralizing epitopes are one of the major reasons for antibody-dependent enhancement. Past studies on the ancestral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have revealed an infectivity-enhancing site on the ancestral SARS-CoV-2 spike protein. However, infection enhancement associated with the SARS-CoV-2 Omicron strain remains elusive. In this study, we examined the antibodies induced by a multiple epitope-based vaccine, which showed infection enhancement for the Omicron strain but not for the ancestral SARS-CoV-2 or Delta strain. By examining the antibodies induced by single epitope-based vaccines, we identified a conserved epitope, IDf (450-469), with neutralizing activity against ancestral SARS-CoV-2, Delta, and Omicron. Although neutralizing epitopes are present in the multiple epitope-based vaccine, other immunodominant non-neutralizing epitopes such as IDg (480-499) can shade their neutralizing activity, leading to infection enhancement of Omicron. Our study provides up-to-date epitope information on SARS-CoV-2 variants to help design better vaccines or antibody-based therapeutics against future variants.
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COVID-19 , Vacunas , Humanos , Epítopos , SARS-CoV-2 , COVID-19/prevención & control , Anticuerpos , Epítopos InmunodominantesRESUMEN
Microneedles can realize the intradermal and transdermal delivery of drugs. However, most conventional microneedles made of metal, polymer and ceramics are unsuitable for the delivery of mRNA drugs that are fragile and temperature-sensitive. This study explores the usage of cryomicroneedles (CryoMNs) for the intradermal delivery of mRNA molecules. Taking luciferase mRNA as an example, we first optimize the formulation of CryoMNs to maximize mRNA stability. Later, in the mouse model, we compare the delivery efficiency with the conventional subcutaneous injection for both the luciferase mRNA and COVID-19 Comirnaty mRNA vaccines, where CryoMNs delivered mRNA vaccines successfully induce specific B-cell antibody, neutralizing activity and T-cell responses. STATEMENT OF SIGNIFICANCE: mRNA vaccines are fragile and temperature-sensitive, so they are mainly delivered by intramuscular injection that often causes pain and requires clinical expertise to immunize patients. Microneedles permit convenient, fast and safe vaccination. However, existing microneedle platforms are ineffective to protect the integrity of mRNA vaccines in fabrication, storage, and administration. This work utilizes cryomicroneedles (CryoMNs) technology to intradermally deliver mRNA. In the mouse model, CryoMNs are compared with the subcutaneous injection for the delivery efficiency of both the luciferase mRNA and COVID-19 Comirnaty mRNA vaccines, where CryoMNs delivered mRNA vaccines successfully produce specific B-cell antibodies, T-cell responses, and neutralizing activity. This work is expected to provide a new delivery strategy for the emerging mRNA therapeutics.
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COVID-19 , Animales , COVID-19/prevención & control , Sistemas de Liberación de Medicamentos , Inyecciones Intradérmicas , Ratones , Agujas , ARN Mensajero/genética , VacunaciónRESUMEN
It has been reported that multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta can reduce neutralization by antibodies, resulting in vaccine breakthrough infections. Virus-antiserum neutralization assays are typically performed to monitor potential vaccine breakthrough strains. However, experiment-based methods took several weeks whether newly emerging variants can break through current vaccines or therapeutic antibodies. To address this, we sought to establish a computational model to predict the antigenicity of SARS-CoV-2 variants by sequence alone. In this study, we firstly identified the relationship between the antigenic difference transformed from the amino acid sequence and the antigenic distance from the neutralization titers. Based on this correlation, we obtained a computational model for the receptor-binding domain (RBD) of the spike protein to predict the fold decrease in virus-antiserum neutralization titers with high accuracy (~0.79). Our predicted results were comparable to experimental neutralization titers of variants, including Alpha, Beta, Delta, Gamma, Epsilon, Iota, Kappa, and Lambda, as well as SARS-CoV. Here, we predicted the fold of decrease of Omicron as 17.4-fold less susceptible to neutralization. We visualized all 1,521 SARS-CoV-2 lineages to indicate variants including Mu, B.1.630, B.1.633, B.1.649, and C.1.2, which can induce vaccine breakthrough infections in addition to reported VOCs Beta, Gamma, Delta, and Omicron. Our study offers a quick approach to predict the antigenicity of SARS-CoV-2 variants as soon as they emerge. Furthermore, this approach can facilitate future vaccine updates to cover all major variants. An online version can be accessed at http://jdlab.online.
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Antígenos Virales , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Antígenos Virales/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , Humanos , Sueros Inmunes , Pruebas de Neutralización , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genéticaRESUMEN
SARS-CoV-2 has been confirmed in over 450 million confirmed cases since 2019. Although several vaccines have been certified by the WHO and people are being vaccinated on a global scale, it has been reported that multiple SARS-CoV-2 variants can escape neutralization by antibodies, resulting in vaccine breakthrough infections. Bacillus Calmette-Guérin (BCG) is known to induce heterologous protection based on trained immune responses. Here, we investigated whether BCG-induced trained immunity protected against SARS-CoV-2 in the K18-hACE2 mouse model. Our data demonstrate that i.v. BCG (BCG-i.v.) vaccination induces robust trained innate immune responses and provides protection against WT SARS-CoV-2, as well as the B.1.617.1 and B.1.617.2 variants. Further studies suggest that myeloid cell differentiation and activation of the glycolysis pathway are associated with BCG-induced training immunity in K18-hACE2 mice. Overall, our study provides the experimental evidence that establishes a causal relationship between BCG-i.v. vaccination and protection against SARS-CoV-2 challenge.
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COVID-19 , SARS-CoV-2 , Animales , Vacuna BCG , COVID-19/prevención & control , Humanos , Melfalán , Ratones , gammaglobulinasRESUMEN
BACKGROUND: Staphylococcus aureus is a common human pathogen capable of causing diverse illnesses with possible recurrent infections. Although recent studies have highlighted the role of cellular immunity in recurrent infections, the mechanism by which S. aureus evades host responses remains largely unexplored. METHODS: This study utilizes in vitro and in vivo infection experiments to investigate difference of pro-inflammatory responses and subsequent adaptive immune responses between adsA mutant and WT S. aureus strain infection. FINDINGS: We demonstrated that adenosine synthase A (AdsA), a potent S. aureus virulence factor, can alter Th17 responses by interfering with NLRP3 inflammasome-mediated IL-1ß production. Specifically, S. aureus virulence factor AdsA dampens Th1/Th17 immunity by limiting the release of IL-1ß and other Th polarizing cytokines. In particular, AdsA obstructs the release of IL-1ß via the adenosine/A2aR/NLRP3 axis. Using a murine infection model, pharmacological inhibition of A2a receptor enhanced S. aureus-specific Th17 responses, whereas inhibition of NLRP3 and caspase-1 downregulated these responses. Our results showed that AdsA contributes to recurrent S. aureus infection by restraining protective Th1/Th17 responses. INTERPRETATION: Our study provides important mechanistic insights for therapeutic and vaccination strategies against S. aureus infections. FUNDING: This work was supported by grants from Shenzhen Peacock project (KQTD2015033-117210153), and Guangdong Science and Technology Department (2020B1212030004) to J.H. and China Postdoctoral Science Foundation (2019M663167) to BZZ. We also thank the L & T Charitable Foundation, the Guangdong Science and Technology Department (2020B1212030004), and the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2019BT02Y198) for their support.
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Proteínas Bacterianas/inmunología , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/enzimología , Factores de Virulencia/inmunología , Adenosina/biosíntesis , Animales , Células Cultivadas , Femenino , Humanos , Evasión Inmune , Interleucina-1beta/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Receptor de Adenosina A2A/metabolismo , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/inmunología , Staphylococcus aureus/patogenicidad , Células THP-1 , Células Th17/inmunologíaRESUMEN
The nucleocapsid protein (NP) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains immunogenic epitopes that can induce cytotoxic T lymphocyte (CTL) against viral infection. This makes the nucleocapsid protein a suitable candidate for developing a vaccine against SARS-CoV-2 infection. This article reports the intradermal delivery of NP antigen using dissolvable microneedle skin patches that could induce both significant B cell and T cell responses.
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Anticuerpos Antivirales/sangre , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , Proteínas de la Nucleocápside de Coronavirus/inmunología , SARS-CoV-2/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Linfocitos B/inmunología , Vacunas contra la COVID-19/administración & dosificación , Proteínas de la Nucleocápside de Coronavirus/administración & dosificación , Ensayo de Inmunoadsorción Enzimática , Inyecciones Intradérmicas/métodos , Ratones , Ratones Endogámicos BALB C , Fosfoproteínas/administración & dosificación , Fosfoproteínas/inmunologíaRESUMEN
Metastasis accounts for 90% of cancer-related deaths and, currently, there are no effective clinical therapies to block the metastatic cascade. A need to develop novel therapies specifically targeting fundamental metastasis processes remains urgent. Here, we demonstrate that Salmonella YB1, an engineered oxygen-sensitive strain, potently inhibits metastasis of a broad range of cancers. This process requires both IFN-γ and NK cells, as the absence of IFN-γ greatly reduces, whilst depletion of NK cells in vivo completely abolishes, the anti-metastatic ability of Salmonella. Mechanistically, we find that IFN-γ is mainly produced by NK cells during early Salmonella infection, and in turn, IFN-γ promotes the accumulation, activation, and cytotoxicity of NK cells, which kill the metastatic cancer cells thus achieving an anti-metastatic effect. Our findings highlight the significance of a self-regulatory feedback loop of NK cells in inhibiting metastasis, pointing a possible approach to develop anti-metastatic therapies by harnessing the power of NK cells.
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Interferón gamma/metabolismo , Interferón gamma/farmacología , Células Asesinas Naturales/inmunología , Activación de Linfocitos/efectos de los fármacos , Metástasis de la Neoplasia/inmunología , Infecciones por Salmonella/metabolismo , Salmonella/genética , Animales , Citocinas/metabolismo , Femenino , Inmunidad Innata , Inmunoterapia/métodos , Interferón gamma/genética , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Infecciones por Salmonella/tratamiento farmacológicoRESUMEN
The Coronavirus Disease 2019 (COVID-19) pandemic is unlikely to abate until sufficient herd immunity is built up by either natural infection or vaccination. We previously identified ten linear immunodominant sites on the SARS-CoV-2 spike protein of which four are located within the RBD. Therefore, we designed two linkerimmunodominant site (LIS) vaccine candidates which are composed of four immunodominant sites within the RBD (RBD-ID) or all the 10 immunodominant sites within the whole spike (S-ID). They were administered by subcutaneous injection and were tested for immunogenicity and in vivo protective efficacy in a hamster model for COVID-19. We showed that the S-ID vaccine induced significantly better neutralizing antibody response than RBD-ID and alum control. As expected, hamsters vaccinated by S-ID had significantly less body weight loss, lung viral load, and histopathological changes of pneumonia. The S-ID has the potential to be an effective vaccine for protection against COVID-19.
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Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , Epítopos Inmunodominantes/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Animales , Cricetinae , Femenino , Células HEK293 , Humanos , Masculino , Mesocricetus , Ratones , Ratones Endogámicos BALB C , VacunaciónRESUMEN
Sodium salicylate, one of the non-steroidal anti-inflammatory drugs, is widely prescribed in the clinic, but a high dose of usage can cause hyperactivity in the central nervous system, including the hippocampus. At present, the neural mechanism underlying the induced hyperactivity is not fully understood, in particular, in the hippocampus under an in vivo condition. In this study, we found that systemic administration of sodium salicylate increased the field excitatory postsynaptic potential slope and the population spike amplitude in a dose-dependent manner in the hippocampal dentate gyrus area of rats with in vivo field potential extracellular recordings, which indicates that sodium salicylate enhances basal synaptic transmission and neural excitation. In the presence of picrotoxin, a GABA-A receptor antagonist, sodium salicylate failed to increase the initial slope of the field excitatory postsynaptic potential and the amplitude of the population spike in vivo. To further explore how sodium salicylate enhances the neural excitation, we made whole-cell patch-clamp recordings from hippocampal slices. We found that perfusion of the slice with sodium salicylate decreased electrically evoked GABA receptor-mediated currents, increased paired-pulse ratio, and lowered frequency and amplitude of miniature inhibitory postsynaptic currents. Together, these results demonstrate that sodium salicylate enhances the neural excitation through suppressing GABAergic synaptic transmission in presynaptic and postsynaptic mechanisms in the hippocampal dentate gyrus area. Our findings may help understand the side effects caused by sodium salicylate in the central nervous system.
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Hipocampo , Salicilato de Sodio , Animales , Giro Dentado/fisiología , Potenciales Postsinápticos Excitadores/fisiología , Hipocampo/fisiología , Ratas , Salicilato de Sodio/farmacología , Transmisión Sináptica/fisiologíaRESUMEN
The S1 subunit of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein contains an immunogenic receptor-binding domain (RBD), which is a promising candidate for the development of a potential vaccine. This study demonstrated that intradermal delivery of an S-RBD vaccine using a dissolvable microneedle skin patch can induce both significant B-cell and significant T-cell responses against S-RBD. Importantly, the outcomes were comparable to that of conventional bolus injection.