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COVID-19 has accounted for more than 6 million deaths worldwide. Bacillus Calmette-Guérin (BCG), the existing tuberculosis vaccine, is known to induce heterologous effects over other infections due to trained immunity and has been proposed to be a potential strategy against SARS-CoV-2 infection. In this report, we constructed a recombinant BCG (rBCG) expressing domains of the SARS-CoV-2 nucleocapsid and spike proteins (termed rBCG-ChD6), recognized as major candidates for vaccine development. We investigated whether rBCG-ChD6 immunization followed by a boost with the recombinant nucleocapsid and spike chimera (rChimera), together with alum, provided protection against SARS-CoV-2 infection in K18-hACE2 mice. A single dose of rBCG-ChD6 boosted with rChimera associated with alum elicited the highest anti-Chimera total IgG and IgG2c Ab titers with neutralizing activity against SARS-CoV-2 Wuhan strain when compared with control groups. Importantly, following SARS-CoV-2 challenge, this vaccination regimen induced IFN-γ and IL-6 production in spleen cells and reduced viral load in the lungs. In addition, no viable virus was detected in mice immunized with rBCG-ChD6 boosted with rChimera, which was associated with decreased lung pathology when compared with BCG WT-rChimera/alum or rChimera/alum control groups. Overall, our study demonstrates the potential of a prime-boost immunization system based on an rBCG expressing a chimeric protein derived from SARS-CoV-2 to protect mice against viral challenge.
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COVID-19 , Mycobacterium bovis , Animais , Camundongos , Vacina BCG/genética , Proteínas Recombinantes de Fusão/genética , SARS-CoV-2 , Vacinas Sintéticas , COVID-19/prevenção & controle , Mycobacterium bovis/genéticaRESUMO
PURPOSE: Knowledge on whether low expressions of HER2 have prognostic impact in early-stage breast cancer (BC) and on its response to current chemotherapy protocols can contribute to medical practice and development of new drugs for this subset of patients, changing treatment paradigms. This study aims to evaluate the impact of HER2-low status on response to neoadjuvant chemotherapy (NACT) and survival outcomes in early-stage HER2-negative BC. METHODS: Records from all BC patients treated with NACT from January 2007 to December 2018 in a single cancer center were retrospectively reviewed. HER2-negative (immunohistochemistry [IHC] 0, + 1, or + 2 non-amplified by in situ hybridization [ISH]) patients were included. HER2-low was defined by IHC + 1 or + 2 ISH non-amplified and HER2-0 by IHC 0. The coprimary objectives were to compare pathological complete response (pCR) and relapse-free survival (RFS) between luminal/HER2-low versus luminal/HER2-0 populations and between triple negative (TNBC)/HER2-low versus TNBC/HER2-0. RESULTS: In total, 855 HER2-negative patients were identified. The median follow-up was 59 months. 542 patients had luminal subtype (63.4%) and 313 had TNBC (36.6%). 285 (33.3%) were HER2-low. Among luminal patients, 145 had HER2 IHC + 1 (26.8%) and 91 had IHC + 2/ISH non-amplified (16.8%). In TNBC, 36 had HER2 IHC + 1 (11.5%) and 13 had IHC + 2/ISH non-amplified (4.2%). Most patients had locally advanced tumors, regardless of subtype or HER2-low status. For luminal disease, pCR was achieved in 13% of HER2-low tumors versus 9.5% of HER2-0 (p = 0.27). Similarly, there was no difference in pCR rates among TNBC: 51% versus 47% in HER2-low versus HER2-0, respectively (p = 0.64). HER2-low was also not prognostic for RFS, with 5-year RFS rates of 72.1% versus 71.7% (p = 0.47) for luminal HER2-low/HER2-0, respectively, and 75.6% versus 70.8% (p = 0.23) for TNBC HER2-low/HER2-0. CONCLUSION: Our data does not support HER2-low as a biologically distinct BC subtype, with no prognostic value on survival outcomes and no predictive effect for pCR after conventional NACT.
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Neoplasias da Mama , Terapia Neoadjuvante , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Quimioterapia Adjuvante , Feminino , Humanos , Recidiva Local de Neoplasia , Receptor ErbB-2/genética , Estudos Retrospectivos , Resultado do TratamentoAssuntos
Disciplinas das Ciências Biológicas , Escolha da Profissão , Família/psicologia , Papel de Gênero , Pesquisadores/psicologia , Ciências Sociais , Disciplinas das Ciências Biológicas/economia , Disciplinas das Ciências Biológicas/educação , Brasil , Países em Desenvolvimento/economia , Engenharia/economia , Equidade de Gênero , Medicina , Projetos Piloto , Qualidade de Vida , Pesquisadores/economia , EstereotipagemRESUMO
BACKGROUND: Tyrosine kinase inhibitors (TKI) and immunotherapy improved survival in metastatic renal cell carcinoma (mRCC). Disparities in treatment access are present in healthcare systems globally. The aim of this study was to analyze survival outcomes of mRCC patients treated with first-line TKIs in the public (PHS) and private (PrS) health system in a Brazilian Cancer Center. MATERIALS AND METHODS: Records from all mRCC patients treated with first-line TKIs from 2007-2018 were reviewed retrospectively. Categorial variables were compared by Fisher's exact test. Survival was estimated by Kaplan-Maier method and survival curves were compared using the log-rank test. Prognostic factors were adjusted by Cox regression model. RESULTS: Of the 171 eligible patients, 37 (21.6%) were PHS patients and 134 (78.4%) were PrS patients. There were no difference in age, gender, or sites of metastasis. PHS patients had worse performance status (ECOG ≥2, 35.1% vs. 13.5%, p=0.007), poorer risk score (IMDC poor risk, 32.4% vs. 16.4%, p=0.09), and less nephrectomies (73% vs. 92.5%, p=0.003) than PrS patients. Median lines of therapy was one for PHS versus two for PrS patients (p=0.03). Median overall survival (OS) was 16.5 versus 26.5 months (p=0.002) and progression-free survival (PFS), 8.4 versus 11 months (p=0.01) for PHS and PrS patients, respectively. After adjusting for known prognostic factors on multivariate analysis, PHS patients still had a higher risk of death (HR: 1.61, 95% CI: 1.01-2.56, p=0.047). CONCLUSION: Patients with mRCC treated via the PHS had worse overall survival, possibly due to poorer prognosis at presentation and less drug access.
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Carcinoma de Células Renais , Neoplasias Renais , Brasil , Carcinoma de Células Renais/tratamento farmacológico , Intervalo Livre de Doença , Humanos , Neoplasias Renais/tratamento farmacológico , Prognóstico , Estudos Retrospectivos , Sunitinibe , Resultado do TratamentoRESUMO
The SARS-CoV-2 coronavirus pandemic calls for coordinated efforts by the scientific community for the development of vaccines. The most advanced strategies have focused on modifications of technologies that were already under development for other viruses, such as SARS, MERS, and even Influenza. Classic and new technologies, such as inactivated and attenuated viruses (non-replicative and replicative), DNA and mRNA vaccines, and nanoparticles containing SARS-CoV-2 antigens, are some of the strategies currently investigated. Although there is a very high expectation for the effectiveness of the most advanced vaccine candidates, there are still no established correlates of protection. Previous experience in vaccine development for other pathogens shows that differences in vaccine formulation can result in diverse immune responses and consequently, different protective properties. Therefore the importance of continuing investigations on a broad range of strategies. Expertise in vaccine development in Brazil was refocused to the new coronavirus. Impressive collaboration between institutions will support further developments until we have available a safe, effective, and economically viable vaccine. Established competence and collaborations will allow preparedness for future challenges and can also be used to address local issues as neglected infectious diseases.
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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
BACKGROUND Bacillus Calmette-Guérin (BCG) is considered a promising live bacterial delivery system. However, several proposals for rBCG vaccines have not progressed, mainly due to the limitations of the available expression systems. OBJECTIVES To obtain a set of mycobacterial vectors using a range of promoters with different strengths based on a standard backbone, previously shown to be stable. METHODS Mycobacterial expression vectors based on the pLA71 vector as backbone, were obtained inserting different promoters (PAN, PαAg, PHsp60, PBlaF* and PL5) and the green fluorescence protein (GFP) as reporter gene, to evaluate features such as their relative strengths, and the in vitro (inside macrophages) and in vivo stability. FINDINGS The relative fluorescence observed with the different vectors showed increasing strength of the promoters: PAN was the weakest in both Mycobacterium smegmatis and BCG and PBlaF* was higher than PHsp60 in BCG. The relative fluorescence observed in a macrophage cell line showed that PBlaF* and PHsp60 were comparable. It was not possible to obtain strains transformed with the extrachromosomal expression vector containing the PL5 in either species. MAIN CONCLUSION We have obtained a set of potentially stable mycobacterial vectors with a arrange of expression levels, to be used in the development of rBCG vaccines.
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Vacina BCG/imunologia , Escherichia coli/imunologia , Vetores Genéticos/imunologia , Proteínas de Fluorescência Verde/imunologia , Mycobacterium bovis/imunologia , Mycobacterium smegmatis/imunologia , Animais , Escherichia coli/genética , Feminino , Vetores Genéticos/genética , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Since the beginning of the COVID-19 pandemic, publications have highlighted the disproportionate impact of the COVID-19 pandemic on academic mothers, mostly focusing on the impact of social distancing and quarantine. A few months later, despite the lack of effective vaccines or therapeutics in sight, many economic activities are being resumed. Nurseries and schools are expected to be among the latest to reopen, which will amplify the impacts of the pandemic on academic mothers. In this letter, we unwrap the pandemic impacts on academic mothers and describe a set of specific short-, medium- and long-term policies that, if implemented, could reduce setbacks for gender equality during the pandemic and can help to level the playing field for academic mothers.
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Infecções por Coronavirus , Mães , Pandemias , Pneumonia Viral , Betacoronavirus , Brasil , COVID-19 , Feminino , Humanos , SARS-CoV-2RESUMO
BACKGROUND: Pancreatic cancer plays an important role in cancer-related mortality. Few studies have been performed in Brazil to characterize patients affected by this disease. We aimed to describe the clinico-pathological characteristics and the survival of patients with pancreatic cancer seen at AC Camargo Cancer Center (ACCCC). METHODS: We included patients ≥ 18-year old, with a histologically confirmed diagnosis of exocrine pancreatic cancer, that attended at least one visit at ACCCC from 2008 to 2016. RESULTS: The study included 739 patients. Median age at diagnosis was 64 years. Most patients were male. About 5% presented a family history of pancreatic cancer. A total of 40% had diabetes and 51.4% presented with ECOG performance status 1. Tumors most often arose in the pancreatic head and roughly half of the patients had metastatic disease at presentation. Median overall survival of patients with potentially resectable disease submitted to surgery at ACCCC was 35.4 months. Median overall survival times of patients with the unresectable and metastatic disease were 14.1 and 9.3 months, respectively. CONCLUSIONS: The features of our population match those of studies done in developed countries. We believe multicentric data from patients with pancreatic cancer in Brazil could enable more effective preventive and therapeutic approaches to the disease.
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Adenocarcinoma/mortalidade , Pâncreas Exócrino/patologia , Pâncreas Exócrino/cirurgia , Neoplasias Pancreáticas/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Institutos de Câncer , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
The expression of many antigens, stimulatory molecules, or even metabolic pathways in mycobacteria such as Mycobacterium bovis BCG or M. smegmatis was made possible through the development of shuttle vectors, and several recombinant vaccines have been constructed. However, gene expression in any of these systems relied mostly on the selection of natural promoters expected to provide the required level of expression by trial and error. To establish a systematic selection of promoters with a range of strengths, we generated a library of mutagenized promoters through error-prone PCR of the strong PL5 promoter, originally from mycobacteriophage L5. These promoters were cloned upstream of the enhanced green fluorescent protein reporter gene, and recombinant M. smegmatis bacteria exhibiting a wide range of fluorescence levels were identified. A set of promoters was selected and identified as having high (pJK-F8), intermediate (pJK-B7, pJK-E6, pJK-D6), or low (pJK-C1) promoter strengths in both M. smegmatis and M. bovisBCG. The sequencing of the promoter region demonstrated that it was extensively modified (6 to 11%) in all of the plasmids selected. To test the functionality of the system, two different expression vectors were demonstrated to allow corresponding expression levels of the Schistosoma mansoni antigen Sm29 in BCG. The approach used here can be used to adjust expression levels for synthetic and/or systems biology studies or for vaccine development to maximize the immune response.
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Expressão Gênica , Vetores Genéticos , Mycobacterium bovis/genética , Regiões Promotoras Genéticas , Animais , Antígenos de Helmintos/biossíntese , Antígenos de Helmintos/genética , Fusão Gênica Artificial , Clonagem Molecular , Genes Reporter , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/genética , Proteínas de Helminto/biossíntese , Proteínas de Helminto/genética , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/genética , Mutagênese , Micobacteriófagos/genética , Mycobacterium smegmatis/genética , Plasmídeos , Reação em Cadeia da Polimerase , Schistosoma mansoni/genética , Análise de Sequência de DNARESUMO
A number of adjuvant formulations were assayed in mice immunized with 3.75 µg of A/California/7/2009 (H1N1) pdm09 influenza vaccine with vitamins A, D and/or E in emulsions or B2 and/or B9 combined with Bordetella pertussis MPLA and/or alum as adjuvants. Squalene was used as positive control, as well as MPLA with alum. The immune response was evaluated by a panel of tests, including a hemagglutination inhibition (HAI) test, ELISA for IgG, IgG1, and IgG2a and IFN-γ, IL-2, IL-6 and IL-10 quantification in splenocyte culture supernatant after stimulus with influenza antigen. Immunological memory was evaluated using a 1/10 dose booster 60 days after the first immunization followed by assessment of the response by HAI, IgG ELISA, and determination of the antibody affinity index. The highest increases in HAI, IgG1 and IgG2a titers were obtained with the adjuvant combinations containing vitamin E, or the hydrophilic combinations containing MPLA and alum or B2 and alum. The IgG1/IgG2a ratio indicates that the response to the combination of B2 with alum would have more Th2 character than the combination of MPLA with alum. In an assay to investigate the memory response, a significant increase in HAI titer was observed with a booster vaccine dose at 60 days after immunization with vaccines containing MPLA with alum or B2 with alum. Overall, of the 27 adjuvant combinations, MPLA with alum and B2 with alum were the most promising adjuvants to be evaluated in humans.
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Adjuvantes Imunológicos/administração & dosagem , Vacinas contra Influenza/imunologia , Vitaminas/administração & dosagem , Compostos de Alúmen/administração & dosagem , Animais , Anticorpos Antivirais/sangue , Antígenos de Bactérias/administração & dosagem , Citocinas/análise , Ensaio de Imunoadsorção Enzimática , Feminino , Testes de Inibição da Hemaglutinação , Memória Imunológica , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/administração & dosagem , Leucócitos Mononucleares/imunologia , Masculino , Camundongos Endogâmicos BALB C , Esqualeno/administração & dosagemRESUMO
Despite the efforts to expand the availability of conjugate vaccines, pneumococcal diseases still pose an enormous burden worldwide. Therefore, several proteins have been investigated as alternative vaccines, alone or in combination with other antigens. With an increasing array of techniques, many of which arose from the publication of the bacterial genome, several proteins have been identified as potential vaccine candidates, and some have even progressed to clinical trials. Also, whole cell vaccines are being studied for the induction of broad ranging protective responses. Here, we briefly summarize the current knowledge on pneumococcal proteins that are being investigated as potential vaccine candidates against pneumococcal infections, and provide an insight on the future generation of protein-based vaccines against Streptococcus pneumoniae.
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Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vacinas Pneumocócicas/imunologia , Vacinas Pneumocócicas/isolamento & purificação , Streptococcus pneumoniae/imunologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Descoberta de Drogas/tendências , Humanos , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/genética , Streptococcus pneumoniae/genética , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/isolamento & purificaçãoRESUMO
Schistosomiasis is a parasitic disease that affects over 200 million people. Vaccine candidates have been identified, including Schistosoma mansoni venom allergen-like proteins (SmVALs) from the SCP/TAPS (sperm-coating protein/Tpx/antigen 5/pathogenesis related-1/Sc7) superfamily. The first SmVAL structure, SmVAL4, was refined to a resolution limit of 2.16â Å. SmVAL4 has a unique structure that could not be predicted from homologous structures, with longer loops and an unusual C-terminal extension. SmVAL4 has the characteristic α/ß-sandwich and central SCP/TAPS cavity. Furthermore, SmVAL4 has only one of the signature CAP cavity tetrad amino-acid residues and is missing the histidines that coordinate divalent cations such as Zn(2+) in other SCP/TAPS proteins. SmVAL4 has a cavity between α-helices 1 and 4 that was observed to bind lipids in tablysin-15, suggesting the ability to bind lipids. Subsequently, SmVAL4 was shown to bind cholesterol in vitro. Additionally, SmVAL4 was shown to complement the in vivo sterol-export phenotype of yeast mutants lacking their endogenous CAP proteins. Expression of SmVAL4 in yeast cells lacking endogenous CAP function restores the block in sterol export. These studies suggest an evolutionarily conserved lipid-binding function shared by CAP proteins such as SmVAL4 and yeast CAP proteins such as Pry1.
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Alérgenos/química , Lipídeos/química , Schistosoma mansoni/química , Peçonhas/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Cromatografia Líquida , Cristalografia por Raios X , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , Homologia de Sequência de AminoácidosRESUMO
Pneumococcal diseases are an important public health problem, with high mortality rates in young children. Although conjugated pneumococcal vaccines offer high protection against invasive pneumococcal diseases, this is restricted to vaccine serotypes, leading to serotype replacement. Furthermore, the current vaccines do not protect neonates. Therefore, several protein-based pneumococcal vaccines have been studied over the last few decades. Our group established a recombinant BCG expressing rPspA-PdT as a prime/rPspA-PdT boost strategy, which protected adult mice against lethal intranasal pneumococcal challenge. Here, we immunized groups of neonate C57/Bl6 mice (6-10) (at 5 days) with rBCG PspA-PdT and a boost with rPspA-PdT (at 12 days). Controls were saline or each antigen alone. The prime/boost strategy promoted an IgG1 to IgG2c isotype shift compared to protein alone. Furthermore, there was an increase in specific memory cells (T and B lymphocytes) and higher cytokine production (IFN-γ, IL-17, TNF-α, IL-10, and IL-6). Immunization with rBCG PspA-PdT/rPspA-PdT showed 100% protection against pulmonary challenge with the WU2 pneumococcal strain; two doses of rPspA-PdT showed non-significant protection in the neonates. These results demonstrate that a prime/boost strategy using rBCG PspA-PdT/rPspA-PdT is effective in protecting neonates against lethal pneumococcal infection via the induction of strong antibody and cytokine responses.
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Streptococcus pneumoniae is a bacterium of great global importance, responsible for more than one million deaths per year. This bacterium is commonly acquired in the first years of life and colonizes the upper respiratory tract asymptomatically by forming biofilms that persist for extended times in the nasopharynx. However, under conditions that alter the bacterial environment, such as viral infections, pneumococci can escape from the biofilm and invade other niches, causing local and systemic disease of varying severity. The polyamine transporter PotABCD is required for optimal survival of the organism in the host. Immunization of mice with recombinant PotD can reduce subsequent bacterial colonization. PotD has also been suggested to be involved in pneumococcal biofilm development. Therefore, in this study we aimed to elucidate the role of PotABCD and polyamines in pneumococcal biofilm formation. First, the formation of biofilms was evaluated in the presence of exogenous polyamines-the substrate transported by PotABCD-added to culture medium. Next, a potABCD-negative strain was used to determine biofilm formation in different model systems using diverse levels of complexity from abiotic surface to cell substrate to in vivo animal models and was compared with its wild-type strain. The results showed that adding more polyamines to the medium stimulated biofilm formation, suggesting a direct correlation between polyamines and biofilm formation. Also, deletion of potABCD operon impaired biofilm formation in all models tested. Interestingly, more differences between wild-type and mutant strains were observed in the more complex model, which emphasizes the significance of employing more physiological models in studying biofilm formation.
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Biofilmes , Streptococcus pneumoniae , Biofilmes/crescimento & desenvolvimento , Streptococcus pneumoniae/fisiologia , Streptococcus pneumoniae/metabolismo , Animais , Camundongos , Poliaminas/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Infecções Pneumocócicas/microbiologia , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Membrana Transportadoras/genética , ÓperonRESUMO
Schistosomiasis, a challenging neglected tropical disease, affects millions of people worldwide. Developing a prophylactic vaccine against Schistosoma mansoni has been hindered by the parasite's biological complexity. In this study, we utilized the innovative phage-display immunoprecipitation followed by a sequencing approach (PhIP-Seq) to screen the immune response of 10 infected rhesus macaques during self-cure and challenge-resistant phases, identifying vaccine candidates. Our high-throughput S. mansoni synthetic DNA phage-display library encoded 99.6% of 119,747 58-mer peptides, providing comprehensive coverage of the parasite's proteome. Library screening with rhesus macaques' antibodies, from the early phase of establishment of parasite infection, identified significantly enriched epitopes of parasite extracellular proteins known to be expressed in the digestive tract, shifting towards intracellular proteins during the late phase of parasite clearance. Immunization of mice with a selected pool of PhIP-Seq-enriched phage-displayed peptides from MEG proteins, cathepsins B, and asparaginyl endopeptidase significantly reduced worm burden in a vaccination assay. These findings enhance our understanding of parasite-host immune responses and provide promising prospects for developing an effective schistosomiasis vaccine.
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Schistosoma mansoni is the primary causative agent of schistosomiasis, which affects 200 million individuals in 74 countries. We generated 163,000 expressed-sequence tags (ESTs) from normalized cDNA libraries from six selected developmental stages of the parasite, resulting in 31,000 assembled sequences and 92% sampling of an estimated 14,000 gene complement. By analyzing automated Gene Ontology assignments, we provide a detailed view of important S. mansoni biological systems, including characterization of metazoa-specific and eukarya-conserved genes. Phylogenetic analysis suggests an early divergence from other metazoa. The data set provides insights into the molecular mechanisms of tissue organization, development, signaling, sexual dimorphism, host interactions and immune evasion and identifies novel proteins to be investigated as vaccine candidates and potential drug targets.
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Schistosoma mansoni/genética , Transcrição Gênica , Animais , Mapeamento Cromossômico , Etiquetas de Sequências Expressas , Genes de Helmintos , Proteínas de Helminto/genética , Humanos , Dados de Sequência Molecular , Schistosoma mansoni/patogenicidade , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/parasitologiaRESUMO
Streptococcus pneumoniae is a bacterial pathogen exclusive to humans, responsible for respiratory and systemic diseases. Pneumococcal protein vaccines have been proposed as serotype-independent alternatives to currently used conjugated polysaccharide vaccines, which have presented limitations regarding their coverage. Previously in our group, pneumococcal surface protein A (PspA) and detoxified pneumolysin (PdT) were genetically fused and the hybrid protein protected mice against pneumococcal challenge, offered higher cross-protection against different strains and showed greater opsonophagocytosis rate than co-administered proteins. As juxtaposed fusion was unstable to upscale production of the protein, flexible (PspA-FL-PdT) and rigid (PspA-RL-PdT) molecular linkers were inserted between the antigens to increase stability. This work aimed to produce recombinant fusion proteins, evaluate their stability after linker insertion, both in silico and experimentally, and enable the production of two antigens in a single process. The two constructs with linkers were cloned into Escherichia coli and hybrid proteins were purified using chromatography; purity was evaluated by SDS-PAGE and stability by Western blot and high performance size exclusion chromatography. PspA-FL-PdT showed higher stability at -20°C and 4°C, without additional preservatives. In silico analyses also showed differences regarding stability of the fusion proteins, with molecule without linker presenting disallowed amino acid positions in Ramachandran plot and PspA-FL-PdT showing the best scores, in agreement with experimental results. Mice were immunized with three doses and different amounts of each protein. Both fusion proteins protected all groups of mice against intranasal lethal challenge. The results show the importance of hybrid protein structure on the stability of the products, which is essential for a successful bioprocess development.
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Vaccine-induced protection against Mycobacterium tuberculosis (Mtb) is usually ascribed to the induction of Th1, Th17, and CD8+ T cells. However, protective immune responses should also involve other immune cell subsets, such as memory T cells. We have previously shown improved protection against Mtb challenge using the rBCG-LTAK63 vaccine (a recombinant BCG strain expressing the LTAK63 adjuvant, a genetically detoxified derivative of the A subunit from E. coli heat-labile toxin). Here we show that mice immunized with rBCG-LTAK63 exhibit a long-term (at least until 6 months) polyfunctional Th1/Th17 response in the draining lymph nodes and in the lungs. This response was accompanied by the increased presence of a diverse set of memory T cells, including central memory, effector memory and tissue-resident memory T cells. After the challenge, the T cell phenotype in the lymph nodes and lungs were characterized by a decrease in central memory T cells, and an increase in effector memory T cells and effector T cells. More importantly, when challenged 6 months after the immunization, this group demonstrated increased protection in comparison to BCG. In conclusion, this work provides experimental evidence in mice that the rBCG-LTAK63 vaccine induces a persistent increase in memory and effector T cell numbers until at least 6 months after immunization, which correlates with increased protection against Mtb. This improved immune response may contribute to enhance the long-term protection.
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The self-cure of rhesus macaques from a schistosome infection and their subsequent strong immunity to a cercarial challenge should provide novel insights into the way these parasites can be eliminated by immunological attack. High-density arrays comprising overlapping 15-mer peptides from target proteins printed on glass slides can be used to screen sera from host species to determine antibody reactivity at the single epitope level. Careful selection of proteins, based on compositional studies, is crucial to encompass only those exposed on or secreted from the intra-mammalian stages and is intended to focus the analysis solely on targets mediating protection. We report the results of this approach using two pools of sera from hi- and lo-responder macaques undergoing self-cure, to screen arrays comprising tegument, esophageal gland, and gastrodermis proteins. We show that, overall, the target epitopes are the same in both groups, but the intensity of response is twice as strong in the high responders. In addition, apart from Sm25, tegument proteins elicit much weaker responses than those originating in the alimentary tract, as was apparent in IFNγR KO mice. We also highlight the most reactive epitopes in key proteins. Armed with this knowledge, we intend to use multi-epitope constructs in vaccination experiments, which seek to emulate the self-cure process in experimental animals and potentially in humans.