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INTRODUCTION: Technological innovations have been instrumental in advancing vaccine design and protective benefit. Improvements in the safety, tolerability, and efficacy/effectiveness profiles have profoundly reduced vaccine-preventable global disease morbidity and mortality. Here we present an original vaccine platform, the Multiple Antigen Presenting System (MAPS), that relies on high-affinity interactions between a biotinylated polysaccharide (PS) and rhizavidin-fused pathogen-specific proteins. MAPS allows for flexible combinations of various PS and protein components. AREAS COVERED: This narrative review summarizes the underlying principles of MAPS and describes its applications for vaccine design against bacterial and viral pathogens in non-clinical and clinical settings. EXPERT OPINION: The utilization of high-affinity non-covalent biotin-rhizavidin interactions in MAPS allows for combining multiple PS and disease-specific protein antigens in a single vaccine. The modular design enables a simplified exchange of vaccine components. Published studies indicate that MAPS technology may support enhanced immunogenic breadth (covering more serotypes, inducing B- and T-cell responses) beyond that which may be elicited via PS- or protein-based conjugate vaccines. Importantly, a more detailed characterization of MAPS-based candidate vaccines is warranted, especially in clinical studies. It is anticipated that MAPS-based vaccines could be adapted and leveraged across numerous diseases of global public health importance.
Existing conjugate vaccines, consisting of pathogen-derived polysaccharides (PSs) and carrier proteins unrelated to the target pathogen, have helped to significantly reduce morbidity and mortality of several bacterial diseases. However, the worldwide burden of infectious diseases targeted by conjugate vaccines is still high. This is mainly due to high pathogen diversity and ongoing evolution, and innovative approaches are needed to respond to these challenges. Multiple Antigen Presenting System (MAPS) is an original vaccine technology that relies on strong molecular interactions between biotin and rhizavidin. MAPS is highly adaptable, as different PS and protein components can be precisely combined and easily exchanged, with limited damage to immunogenic epitopes (PS and protein features recognized by the immune system). Unlike existing conjugate vaccines, MAPS complexes contain pathogen-specific proteins, able to elicit broad immune responses directed against the pathogen. To date, investigational MAPS-based vaccines have been evaluated in several non-clinical studies; one candidate pneumococcal vaccine has been evaluated in early phase clinical studies in healthy children and adults (including older adults). In these clinical studies, the MAPS-based vaccine candidate was well tolerated and induced robust immune responses. If the favorable profile of MAPS-based vaccines is confirmed in further studies, these vaccines could be used against infectious diseases associated with significant morbidity and mortality.
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Infecções Pneumocócicas , Vacinas Pneumocócicas , Humanos , Infecções Pneumocócicas/prevenção & controle , Vacinas Conjugadas , Anticorpos AntibacterianosRESUMO
Bloodstream infections in low- and middle-income countries (LMICs) are most frequently attributed to invasive Salmonella disease caused by four primary serovars of Salmonella enterica: Typhi, Paratyphi A, Typhimurium, and Enteritidis. We showed previously that a bivalent vaccine targeting S. Typhi and S. Paratyphi A using a Multiple Antigen-Presenting System (MAPS) induced functional antibodies against S. Typhi and S. Paratyphi. In the current study, we describe the preclinical development of a first candidate quadrivalent combination Salmonella vaccine with the potential to cover all four leading invasive Salmonella serotypes. We showed that the quadrivalent Salmonella MAPS vaccine, containing Vi from S. Typhi, O-specific Polysaccharide (OSP) from S. Paratyphi A, S. Enteritidis and S. Typhimurium, combined with the Salmonella-specific protein SseB, elicits robust and functional antibody responses to each of the components of the vaccine. Our data indicates that the application of MAPS technology to the development of vaccines targeting invasive forms of Salmonella is practical and merits additional consideration.
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Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide. To date, the mainstay of vaccination involves the use of Mycobacterium bovis bacillus Calmette-Guérin (BCG), a live-attenuated vaccine that confers protection against extrapulmonary disease in infants and children but not against lung disease. Thus, there is an urgent need for novel vaccines. Here, we show that a multicomponent acellular vaccine (TB-MAPS) induces robust antibody responses and long-lived systemic and tissue-resident memory Th1, Th17, and cytotoxic CD4+ and CD8+ T cells, and promotes trained innate immunity mediated by γδT and NKT cells in mice. When tested in a mouse aerosol infection model, TB-MAPS significantly reduced bacterial loads in the lungs and spleens to the same extent as BCG. When used in conjunction with BCG, TB-MAPS further enhanced BCG-mediated protection, especially in the lungs, further supporting this construct as a promising TB vaccine candidate. IMPORTANCE Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide. Here, we evaluate a novel vaccine which induces a broad immune response to Mycobacterium tuberculosis including robust antibody responses and long-lived systemic and tissue-resident memory Th1, Th17, and cytotoxic CD4+ and CD8+ T cells. When tested in a mouse aerosol infection model, this vaccine significantly reduced bacterial loads in the lungs and spleens to the same extent as BCG. When used in conjunction with BCG, TB-MAPS further enhanced BCG-mediated protection, especially in the lungs, further supporting this construct as a promising TB vaccine candidate.
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Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculose , Animais , Camundongos , Vacina BCG , Linfócitos T CD8-Positivos , Tuberculose/prevenção & controle , Antígenos de BactériasRESUMO
The advent of pneumococcal conjugate vaccines led to the near disappearance of most of the included serotypes in high-income settings but also the rise of nonvaccine-type colonization and disease. Alternative strategies, using genetically conserved proteins as antigens, have been evaluated preclinically and clinically for years, so far unsuccessfully. One possible explanation for the failure of these efforts is that the choice of antigens may not have been sufficiently guided by an understanding of the gene expression pattern in the context of infection. Here, we present a targeted transcriptomic analysis of 160 pneumococcal genes encoding bacterial surface-exposed proteins in mouse models, human colonization, and human meningitis. We present the overlap of these different transcriptomic profiles. We identify two bacterial genes that are highly expressed in the context of mouse and human infection: SP_0282, an IID component of a mannose phosphotransferase system (PTS), and SP_1739, encoding RNase Y. We show that these two proteins can confer protection against pneumococcal nasopharyngeal colonization and intraperitoneal challenge in a murine model and generate opsonophagocytic antibodies. This study emphasizes and confirms the importance of studies of pneumococcal gene expression of bacterial surface proteins during human infection and colonization and may pave the way for the selection of a protein-based vaccine candidate.
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Infecções Pneumocócicas , Animais , Proteínas de Bactérias/genética , Humanos , Camundongos , Nasofaringe/microbiologia , Infecções Pneumocócicas/microbiologia , Vacinas Pneumocócicas/genética , Sorogrupo , Streptococcus pneumoniae/genética , Transcriptoma , Vacinas ConjugadasRESUMO
Capsular polysaccharides (CPSs) are important antigenic targets against bacterial infections. As T-independent antigens, however, CPSs elicit short-lived immune responses in adults and are poorly immunogenic in young children. Coupling CPS with protein carriers enhances anti-CPS responses and generates long-lasting immune memory. However, the mechanisms whereby carrier proteins accomplish this are not fully understood. Here, we dissect different mechanisms whereby carrier proteins enhance anti-CPS immunity. We show how coupling CPS with protein carriers modifies the interaction of CPS with antigen-presenting cells, enables a dual-activation mechanism for CPS-specific B cells via interaction with CPS- or carrier-specific T helper cells, and potentiates the recall of anti-CPS responses by engaging memory T helper cells during subsequent vaccination or bacterial exposure. Our findings provide new insights into the immunological basis of carrier-mediated anti-CPS immunity and may help in the design of more effective CPS-based vaccines. IMPORTANCE Polysaccharide capsules, the outermost shells of many bacterial pathogens, play a role in pathogenesis and protect bacteria against the immune system. Generating antipolysaccharide antibodies by vaccination has provided effective protection against infectious diseases caused by encapsulated bacteria. However, most pure polysaccharide preparations are poorly immunogenic, particularly in young children. To circumvent this problem, vaccines have been developed using polysaccharides associated with protein carriers. The precise mechanism whereby protein carriers enhance the immunogenicity of the polysaccharide remains unclear. The significance of our research is in elucidating the different roles played by carriers in facilitating polysaccharide processing and presentation, priming polysaccharide-specific B cells, and potentiating recall antipolysaccharide responses. Overall, our work provides new insights into the immunological basis of carrier-mediated antipolysaccharide immunity and may help in the design of more effective polysaccharide-based vaccines.
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Proteínas de Transporte , Polissacarídeos Bacterianos , Adulto , Anticorpos , Anticorpos Antibacterianos , Formação de Anticorpos , Antígenos , Cápsulas Bacterianas , Criança , Pré-Escolar , Humanos , Vacinas ConjugadasRESUMO
The induction of T cell responses by vaccination is important for protection against infection. We have previously shown that immunization with a killed Streptococcus pneumoniae whole-cell vaccine (SPWCV) by either intranasal immunization or subcutaneous immunization induced T cell responses to SPWCV. Protection against colonization by S. pneumoniae is dependent on CD4+ IL-17A production induced by immunization. Here, we present detailed protocols for preparation of SPWCV, immunization of mice, and assay for T cell responses in blood and splenocytes in immunized mice.
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Infecções Pneumocócicas , Streptococcus pneumoniae , Administração Intranasal , Animais , Anticorpos Antibacterianos , Camundongos , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Streptococcus pneumoniae/imunologia , Linfócitos T/imunologia , VacinaçãoRESUMO
Infections by Salmonella Typhi and Paratyphi A strain are still a major cause of morbidity and mortality in developing countries. Generation of antibodies against the Vi capsular polysaccharide of S. Typhi via either pure polysaccharide or protein-polysaccharide conjugate is a very effective way to protect against S. Typhi. To date, there is no commercially available vaccine against S. Paratyphi A. The O-specific polysaccharide (OSP) has been generally considered a good vaccine target for Paratyphi A. Here, a bivalent vaccine against Vi and OSP was generated using the Multiple Antigen Presenting System (MAPS). Three different protein constructs, including CRM197, rEPA of Pseudomonas, and a pneumococcal fusion protein SP1500-SP0785, were fused to Rhizavidin (Rhavi) and evaluated their impact on immunogenicity when incorporated as fusion proteins affinity-bound to the two polysaccharides. We compared the antibody responses, antibody avidity, and cidal activity of sera post-immunization with monovalent vs. combination vaccines. We also wished to evaluate the generation of Vi-specific memory B cells in mice. We found little interference when combination vaccine was compared to monovalent vaccines with respect to antibody concentration and cidal activity of sera. Significant affinity maturation was noted for both Vi and OSP antigens. Thus, our preclinical results with a combination Vi- and OSP-MAPS vaccine strongly support the feasibility of this approach and its application of this approach to other important salmonella and Shigella species.
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Background: Anterior cervical discectomy and fusion (ACDF) has been widely performed to treat cervical generative diseases. Cage subsidence is a complication after ACDF. Although it is known that segmental kyphosis, acceleration of adjacent segmental disease, and restenosis may occur due to cages subsidence; however detailed research comparing zero-profile cages (ROI-C) and conventional plate and cage construct (CPC) on cage subsidence has been lacking. Objective: The objectives of this study was to compare the rate of postoperative cage subsidence between zero profile anchored spacer (ROI-C) and conventional cage and plate construct (CPC) and investigate the risk factors associated with cage subsidence following ACDF. Methods: Seventy-four patients with ACDF who received either ROI-C or CPC treatment from October 2013 to August 2018 were included in this retrospective cohort study. Clinical and radiological outcomes and the incidence of cage subsidence at final follow up-were compared between groups. All patients were further categorized into the cage subsidence (CS) and non-cage subsidence (NCS) groups for subgroup analysis. Results: The overall subsidence rate was higher in the ROI-C group than in the CPC group (66.67 vs. 38.46%, P = 0.006). The incidence of cage subsidence was significantly different between groups for multiple-segment surgeries (75 vs. 34.6%, P = 0.003), but not for single-segment surgeries (54.55 vs. 42.30%, P = 0.563). Male sex, operation in multiple segments, using an ROI-C, and over-distraction increased the risk of subsidence. Clinical outcomes and fusion rates were not affected by cage subsidence. Conclusion: ROI-C use resulted in a higher subsidence rate than CPC use in multi-segment ACDF procedures. The male sex, the use of ROI-C, operation in multiple segments, and over-distraction were the most significant factors associated with an increase in the risk of cage subsidence.
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OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of the Wiltse approach and percutaneous pedicle screw placement under O-arm navigation for the treatment of thoracolumbar fracture. METHODS: We enrolled a total of 54 patients with neurologically intact thoracolumbar fracture who received minimally invasive treatments between October 2014 and October 2018 in this retrospective study. Among these, 28 patients (22 males and six females, with a mean age of 48.6 ± 9.6 years) were treated with pedicle screw fixation through the Wiltse approach (WPSF), and another 26 (15 males and 11 females, with a mean age of 45.7 ± 10.6 years) received percutaneous pedicle screw fixation under O-arm navigation (OPSF). Statistical methods were used to perform a detailed comparison of clinical outcomes, radiologic findings, and complications between the two groups obtained preoperatively, postoperatively, and at last follow-up. RESULTS: All patients underwent surgery successfully and finished a follow-up of more than 12 months. No serious complications, such as infection, blood vessel injury, or spinal cord or nerve root injury occurred. Visual analog scale (VAS) scores, Oswestry disability index (ODI) scores, local Cobb angle (LCA), vertebral wedge angle (VWA), and R value were notably improved after surgery, though there was no clear discrepancy between the groups at each time point (P > 0.05). During the follow-up period, no patients developed neurological impairment or implant-related complications, and no patients underwent revision surgery. The WPSF group had a significantly shorter operation time than the OPSF group (68.1 ± 9.8 vs 76.1 ± 9.0 minutes, P = 0.005). Moreover, the WPSF group showed less cost of surgery than the WPSF group (48142.1 ± 1430.1 vs 59035.4 ± 1152.7 CNY, P < 0.001). There were no significant differences between the two groups in terms of the intraoperative bleeding, length of incision, or postoperative hospitalization time (P > 0.05). The accuracy of pedicle screw placement was 95.2% (160/168) in the WPSF group and 96.8% (151/156) in the OPSF group, with no significant difference between the groups (P = 0.432). CONCLUSION: Both WPSF and OPSF were safe and effective for the treatment of thoracolumbar fracture. Although the two groups showed favorable clinical and radiologic outcomes through to final follow-up, we recommended the minimally invasive WPSF given its shorter operation time and lower cost of surgery.
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Fluoroscopia/instrumentação , Vértebras Lombares/cirurgia , Parafusos Pediculares , Fraturas da Coluna Vertebral/cirurgia , Fusão Vertebral/métodos , Vértebras Torácicas/cirurgia , Adulto , Avaliação da Deficiência , Feminino , Humanos , Cuidados Intraoperatórios , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos RetrospectivosRESUMO
When patients combined thoracolumbar osteoporotic vertebral compression fracture (OVCF) with lumbar degenerative disease, whose main clinical manifestations are distal lumbosacral pain (DLP), the therapeutic schedule should be made cautiously. We reported an 80-year-old female presented with long-term lumbosacral pain accused of lumbar disc herniation. Percutaneous kyphoplasty (PKP) had been received because of OVCF at L1 vertebral body. Twenty days ago, the elderly felt the DLP was aggravated with no obvious reason. Magnetic resonance imaging (MRI) showed the fresh compression fracture of L2 vertebral body, but the palpation found absence of focal tenderness. Then, we chose to perform PKP at L2 vertebral body, and the patient felt substantial pain relief of lumbosacral area after operation. This case showed that patient manifested as DLP that combined thoracolumbar OVCF with lumbar degenerative disease, PKP has a significant relieving effect on lumbosacral pain.
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Fraturas por Compressão , Cifoplastia , Dor Lombar , Fraturas da Coluna Vertebral , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas por Compressão/diagnóstico por imagem , Fraturas por Compressão/cirurgia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Região Lombossacral , Estudos Retrospectivos , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/cirurgia , Resultado do TratamentoRESUMO
BACKGROUND: HPV16 E6/E7 proteins are the main oncogenes and only long-term persistent infection causes lung cancer. Our previous studies have shown that HPV16 E6/E7 protein up-regulates the expression of GLUT1 in lung cancer cells. However, whether E6 and E7 protein can promote the glucose uptake of GLUT1 and its molecular mechanism are unclear. METHODS: The regulatory relationships of E6 or E7, miR-451, CAB39, PI3K/AKT, and GLUT1 were detected by double directional genetic manipulations in lung cancer cell lines. Immunofluorescence and flow cytometry were used to detect the effect of CAB39 on promoting the translocation to the plasma membrane of GLUT1. Flow cytometry and confocal microscopy were performed to detect the glucose uptake levels of GLUT1. RESULTS: The overexpression both E6 and E7 proteins significantly down-regulated the expression level of miR-451, and the loss of miR-451 further up-regulated the expression of its target gene CAB39 at both protein and mRNA levels. Subsequently, CAB39 up-regulated the expression of GLUT1 at both protein and mRNA levels. Our results demonstrated that HPV16 E6/E7 up-regulated the expression and activation of GLUT1 through the HPV-miR-451-CAB39-GLUT1 axis. More interestingly, we found that CAB39 prompted GLUT1 translocation to the plasma membrane and glucose uptake, and this promotion depended on the PI3K/AKT pathway. CONCLUSION: Our findings provide new evidence to support the critical roles of miR-451 and CAB39 in the pathogenesis of HPV-related lung cancer.
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Nontyphoidal Salmonella and Salmonella Paratyphi are responsible for significant morbidity and mortality worldwide. To date, no vaccine has been licensed against these organisms. The development of effective vaccines remains an urgent priority. In this review, the rationale for and current status of various vaccine candidates against S. Paratyphi and nontyphoidal Salmonella are presented, with a focus on the research findings from the 2019 International Conference on Typhoid and Other Invasive Salmonelloses. Additionally, other vaccine candidates that are currently undergoing clinical development are highlighted. Future approaches, which may include antigens that are genetically conserved across Salmonella and confer broad, non-serotype-specific protection, are also discussed.
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Infecções por Salmonella , Vacinas contra Salmonella , Febre Tifoide , Vacinas Tíficas-Paratíficas , Humanos , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/prevenção & controle , Salmonella paratyphi ARESUMO
The available pneumococcal conjugate vaccines provide protection against only those serotypes that are included in the vaccine, which leads to a selective pressure and serotype replacement in the population. An alternative low-cost, safe and serotype-independent vaccine was developed based on a nonencapsulated pneumococcus strain. This study evaluates process intensification to improve biomass production and shows for the first time the use of perfusion-batch with cell recycling for bacterial vaccine production. Batch, fed-batch, and perfusion-batch were performed at 10 L scale using a complex animal component-free culture medium. Cells were harvested at the highest optical density, concentrated and washed using microfiltration or centrifugation to compare cell separation methods. Higher biomass was achieved using perfusion-batch, which removes lactate while retaining cells. The biomass produced in perfusion-batch would represent at least a fourfold greater number of doses per cultivation than in the previously described batch process. Each strategy yielded similar vaccines in terms of quality as evaluated by western blot and animal immunization assays, indicating that so far, perfusion-batch is the best strategy for the intensification of pneumococcal whole-cell vaccine production, as it can be integrated to the cell separation process keeping the same vaccine quality.
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Técnicas de Cultura Celular por Lotes/instrumentação , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Animais , Técnicas de Cultura Celular por Lotes/métodos , Biomassa , Reatores Biológicos , Desenho de Equipamento , Feminino , Humanos , Imunização , Camundongos Endogâmicos C57BL , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico , Pneumonia Pneumocócica/imunologia , Pneumonia Pneumocócica/prevenção & controle , Streptococcus pneumoniae/citologiaRESUMO
Ultrasensitive mechano-stimuli photoluminescence enhancement was observed in pyramid-like zinc oxide nanoparticles (ZnO NPs), which are fabricated by a facile hydrothermal route. The response of the ZnO NPs to mechanical stimuli is so sensitive that even an ant walking and acoustic vibration can trigger the luminescence enhancement. The mechanism for this unusual behavior was attributed to the electron injection process between crystal boundaries. Thus, this work opens up the possibility of detecting slight mechanical stimuli wirelessly, rapidly, and sensitively. Importantly, the sensitive response of the NPs to sound waves can find potential application in devices for hearing-impaired people.
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Staphylococcus aureus is a major cause of morbidity and mortality worldwide. S. aureus colonizes 20 to 80% of humans at any one time and causes a variety of illnesses. Strains that are resistant to common antibiotics further complicate management. S. aureus vaccine development has been unsuccessful so far, largely due to the incomplete understanding of the mechanisms of protection against this pathogen. Here, we studied the role of different aspects of adaptive immunity induced by an S. aureus vaccine in protection against S. aureus bacteremia, dermonecrosis, skin abscess, and gastrointestinal (GI) colonization. We show that, depending on the challenge model, the contributions of vaccine-induced S. aureus-specific antibody and Th1 and Th17 responses to protection are different: antibodies play a major role in reducing mortality during S. aureus bacteremia, whereas Th1 or Th17 responses are essential for prevention of S. aureus skin abscesses and the clearance of bacteria from the GI tract. Both antibody- and T-cell-mediated mechanisms contribute to prevention of S. aureus dermonecrosis. Engagement of all three immune pathways results in the most robust protection under each pathological condition. Therefore, our results suggest that eliciting multipronged humoral and cellular responses to S. aureus antigens may be critical to achieve effective and comprehensive immune defense against this pathogen.IMPORTANCES. aureus is a leading cause of healthcare- and community-associated bacterial infections. S. aureus causes various illnesses, including bacteremia, meningitis, endocarditis, pneumonia, osteomyelitis, sepsis, and skin and soft tissue infections. S. aureus colonizes between 20 and 80% of humans; carriers are at increased risk for infection and transmission to others. The spread of multidrug-resistant strains limits antibiotic treatment options. Vaccine development against S. aureus has been unsuccessful to date, likely due to an inadequate understanding about the mechanisms of immune defense against this pathogen. The significance of our work is in illustrating the necessity of generating multipronged B-cell, Th1-, and Th17-mediated responses to S. aureus antigens in conferring enhanced and broad protection against S. aureus invasive infection, skin and soft tissue infection, and mucosal colonization. Our work thus, provides important insights for future vaccine development against this pathogen.
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Imunidade Adaptativa , Imunidade Humoral , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/prevenção & controle , Vacinas Antiestafilocócicas/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Bacteriemia/imunologia , Bacteriemia/prevenção & controle , Feminino , Trato Gastrointestinal/microbiologia , Imunização Passiva , Camundongos , Camundongos Endogâmicos C57BL , Necrose/imunologia , Necrose/microbiologia , Necrose/prevenção & controle , Pele/microbiologia , Pele/patologia , Infecções dos Tecidos Moles/imunologia , Infecções dos Tecidos Moles/microbiologia , Infecções dos Tecidos Moles/prevenção & controle , Staphylococcus aureus , Células Th1/imunologia , Células Th17/imunologiaRESUMO
Phonon-assisted anti-Stokes photoluminescence (ASPL) up-conversion lies at the heart of optical refrigeration in solids. The thermal energy contained in the lattice vibrations is taken away by the emitted anti-Stokes photons' ASPL process, resulting in laser cooling of solids. To date, net laser cooling of solids is limited in rare-earth (RE)-doped crystals, glasses, and direct band gap semiconductors. Searching more solid materials with efficient phonon-assisted photoluminescence up-conversion is important to enrich optical refrigeration research. Here, we demonstrate the phonon-assisted PL up-conversion process from the silicon vacancy (SiV) center in diamond for the first time by studying ASPL spectra for the dependence of temperature, laser power, and excitation energy. Although net cooling has not been observed, our results show that net laser cooling might be eventually achieved in diamond by improving the external quantum efficiency to higher than 95%. Our work provides a promising route to investigate the laser cooling effect in diamond.
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Conjugate vaccines against Streptococcus pneumoniae have significantly reduced the incidence of diseases caused by the serotypes included in those vaccines; however, there is still a need for vaccines that confer serotype-independent protection. In the current study, we have constructed a library of conserved surface proteins from S. pneumoniae and have screened for IL-17A and IL-22 production in human immune cells obtained from adenoidal/tonsillar tissues of children and IL-17A production in splenocytes from mice that had been immunized with a killed whole-cell vaccine or previously exposed to pneumococcus. A positive correlation was found between the rankings of proteins from human IL-17A and IL-22 screens, but not between those from human and mouse screens. All proteins were tested for protection against colonization, and we identified protective antigens that are IL-17A dependent. We found that the likelihood of finding a protective antigen is significantly higher for groups of proteins ranked in the top 50% of all three screens than for groups of proteins ranked in the bottom 50% of all three. The results thus confirmed the value of such screens for identifying Th17 antigens. Further, these experiments have evaluated and compared the breadth of human and mouse Th17 responses to pneumococcal colonization and have enabled the identification of potential vaccine candidates based on immunological responses in mouse and human cells.
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Antígenos de Bactérias/imunologia , Portador Sadio/prevenção & controle , Interleucina-17/metabolismo , Interleucinas/metabolismo , Leucócitos Mononucleares/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Animais , Humanos , Camundongos Endogâmicos C57BL , Modelos Animais , Interleucina 22RESUMO
ZnO as an eco-friendly material shows bright luminescence under UV illumination when it is tailored into nanoscale size, which makes it a promising luminescent nanomaterial. However, the poor stability of ZnO hinders its applications drastically. In this work, multi-ZnO-cores@uni-BaSO4-shell (mZnO@uBaSO4) nanocomposite has been prepared through a non-equilibrium sorption process employing ZnO QDs as the "seeds" and BaSO4 as the "valve". The mZnO@uBaSO4 nanocomposite shows improved photo-, thermal- and ambient-stability compare with bare ZnO QDs. The fluorescence efficiency of the mZnO@uBaSO4 nanocomposite decreases little even after 60â¯h of UV irradiation compare with ZnO QDs. The mZnO@uBaSO4 nanocomposite shows bright luminescence with little decrease even the ambient temperature up to 160⯰C and the nanocomposite shows strong resistance to harsh environment. By coating the mZnO@uBaSO4 nanocomposite and commercial phosphors onto UV-chip, light-emitting diode (LED) with correlated color temperature, Commission Internationale de L'Eclairage coordinate, color rendering index and luminous efficiency of 6109â¯K, (0.32, 0.33), 85 and 47.33â¯lm/W have been realized, and this will make a great step towards eco-friendly UV-pumped LEDs.
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Van der Waals heterostructures (vdWHs) have opened new avenues for fundamental scientific studies and design of novel devices. Although numerous reports have demonstrated vdWH optoelectronic devices, no report on vdWH lasers can be found to date. In this paper we demonstrated electrically driven vdWH lasers for the first time, and the lasers were realized from ZnO microwire/MgO/p-GaN structures. By coating Ag films on the top surfaces of the ZnO microwires, the current injection and lasing directionality of the vdWH lasers have been improved significantly, and this improvement can be attributed to the high conductivity and reflectivity of the Ag film. The output power of the device can reach 2.41 µW under 14 mA drive current, which is among the highest values ever reported for ZnO based lasers. Our results may provide a promising way to electrically pumped lasers based on micro/nano-structures.
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Room-temperature upconversion emission up to eight-photon absorption is demonstrated from diamond single crystals under femtosecond laser excitation for the first time. The low concentration of defects and impurities is attributed to the support of free excitons emission at 235 nm. Nonlinear optical properties are also investigated by using an open-aperture Z-scan technique. The corresponding three-, five-, and eight-photon absorption coefficients of the diamonds are found to be 1.8 × 10-2 cm3/GW2, 5 × 10-9 cm7/GW4, and 1.6 × 10-19 cm13/GW7, respectively. Considering its high hardness and high thermal conductivity, diamonds are a versatile nonlinear optical material suitable for high-power deep ultraviolet applications under multiphoton excitation.