18 research outputs found

    Utilização de radiação UVC para desinfecção do ar nos ambientes / UVC radiation utilization to disinfect environments air

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    O presente trabalho apresenta o projeto de um dispositivo e os testes realizados em um sistema de auxílio na prevenção de contaminações pelo Sars-Cov2 com a desinfecção do ar pela utilização de UVC como ação germicida. O sistema foi testado com E.colis e proporcionou no ar tratado uma visível taxa de inativação das colônias de bactérias aspergidas em sua entrada

    Antibody recognition of plasmodium falciparum infected red blood cells by symptomatic and asymptomatic individuals in the brazilian Amazon

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    In the Amazon Region, there is a virtual absence of severe malaria and few fatal cases of naturally occurring Plasmodium falciparum infections; this presents an intriguing and underexplored area of research. In addition to the rapid access of infected persons to effective treatment, one cause of this phenomenon might be the recognition of cytoadherent variant proteins on the infected red blood cell (IRBC) surface, including the var gene encoded P. falciparum erythrocyte membrane protein 1. In order to establish a link between cytoadherence, IRBC surface antibody recognition and the presence or absence of malaria symptoms, we phenotype-selected four Amazonian P. falciparum isolates and the laboratory strain 3D7 for their cytoadherence to CD36 and ICAM1 expressed on CHO cells. We then mapped the dominantly expressed var transcripts and tested whether antibodies from symptomatic or asymptomatic infections showed a differential recognition of the IRBC surface. As controls, the 3D7 lineages expressing severe disease-associated phenotypes were used. We showed that there was no profound difference between the frequency and intensity of antibody recognition of the IRBC-exposed P. falciparum proteins in symptomatic vs. asymptomatic infections. The 3D7 lineages, which expressed severe malaria-associated phenotypes, were strongly recognised by most, but not all plasmas, meaning that the recognition of these phenotypes is frequent in asymptomatic carriers, but is not necessarily a prerequisite to staying free of symptoms.In the Amazon Region, there is a virtual absence of severe malaria and few fatal cases of naturally occurring Plasmodium falciparum infectionsthis presents an intriguing and underexplored area of research. In addition to the rapid access of infected p1095598601FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2009/17114-3576128/2008-2To Wolfgang Fischer and Márcio Yamamoto, for sequencing of DBLα tag sequences, and to Drs Mauro Shugiro Tada and Tony Katsuragawa, for help with data and sample collection at the site

    TLR4-Mediated Placental Pathology and Pregnancy Outcome in Experimental Malaria

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    Malaria-associate pregnancy has a significant impact on infant morbidity and mortality. The detrimental effects of malaria infection during pregnancy have been shown to correlate with immune activation in the placental tissue. Herein we sought to evaluate the effect of Toll-like receptors (TLRs) activation on placental malaria (PM) development by using the Plasmodium berghei NK65(GFP) infection model. We observed that activation of the innate immune system by parasites leads to PM due to local inflammation. We identified TLR4 activation as the main pathway involved in the inflammatory process in the placental tissue since the absence of functional TLR4 in mice leads to a decrease in the pro-inflammatory responses, which resulted in an improved pregnancy outcome. Additionally, a similar result was obtained when infected pregnant mice were treated with IAXO-101, a TLR4/CD14 blocker. Together, this study illustrates the importance of TLR4 signalling for the generation of the severe inflammatory response involved in PM pathogenesis. Therefore, our results implicate that TLR4 blockage could be a potential candidate for therapeutic interventions to reduce malaria-induced pathology both in the mother and the fetus.Fundação de Amparo a Pesquisa do Estado de São Paulo - FAPESPCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESConselho Nacional de Desenvolvimento Científico e Tecnológico - CNPqUniv Fed São Paulo, Dept Ciencias Biol, Diadema, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Parasitol, São Paulo, BrazilHosp Israelita Albert Einstein, São Paulo, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Biol Celular & Desenvolvimento, São Paulo, BrazilUniv Estadual Campinas, Dept Genet Evolucao & Bioagentes, Inst Biol, Campinas, SP, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Imunol, São Paulo, BrazilUniv São Paulo, Dept Analises Clin & Toxicol, Fac Ciencias Farmaceut, São Paulo, BrazilUniv Fed São Paulo, Dept Ciencias Biol, Diadema, BrazilFAPESP: 2009/53889-0FAPESP: 2014/09964-5FAPESP: 2014/20451-0FAPESP: 2012/16525-2FAPESP: 2011/17880-8FAPESP: 2013/16417-8FAPESP: 2011/19048-8FAPESP: 2013/00981-1FAPESP: 2015/06106-0]CAPES: AUX-PE-PNPD 2751/2010CNPq: 475771/2009-5Web of Scienc

    Analysis of the role of genes bir in the host-pathogen relation and development of proteoliposomes for the use in vaccines against blood stage forms of Plasmodium.

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    A relação evolutiva entre mamíferos e Plasmodium compreende infecções com reflexos adaptativos de ambos os lados. A evasão imune pelo parasita e a aquisição imune do hospedeiro contra antígenos importantes são extremos de um longo processo. Genes e antígenos variantes do parasita funcionam nesse processo desempenhando papel evasivo, de citoaderência e manutenção do processo infeccioso. Hospedeiros podem adquirir imunidade efetiva por vacinas contra antígenos variantes e antígenos de caráter reinvasivo. Testamos aqui três desenhos experimentais visando: 1- Definir se antigenos variantes BIR estão associados a citoadesão em infecção murina e se sua localização é em eritrócitos infectados. 2- O papel de um transgene controlado por um promotor de genes variantes no processo adaptativo infeccioso, frente a hospedeiros que diferem em apenas um único gene. 3- Criação de um modelo vacinal aplicável a qualquer antígeno relevante em infecções pelo gênero Plasmodium. Como resultados obtivemos que: 1- Antigenos BIR não parecem estar relacionados na cito adesão em modelo murino. Identificamos um outro grupo de antígenos com domínio LCCL que talvez desempenhe um papel de ligante. 2- promotores bir podem sofrer modulação em uma única infecção que difiere em somente um gene em hospedeiros. Os efeitos desencadeados foram maior parasitemia, anergia e tolerância imune sem afetar a morbidade da infecção de maneira nociva ao hospedeiro. Esse efeito parece ser mediado por subpopulações parasitarias usando exossomos entre parasita e hospedeiro. 3- Produzimos um sistema funcional de produção de proteínas recombinantes fusionadas a GPI que permite integração em lipossomos para usos vacinais. A prova de princípio foi o uso de antígenos PfRH5-GPI recombinantes em teste vacinal que conseguiram gerar anticorpos com alta atividade inibitória em cultivos de P. falciparum. Tomados em conjunto mostramos que o hospedeiro é capaz influenciar a expressão de transgenes controlados por promotores bir e que proteolipossomos contendo antígenos relevantes, como PfRH5, possuem potencial protetor quando vacinados contra malaria.The relation between mammals and Plasmodium comprise infections with adaptive reflections for both sides. The immune evasion by parasites and immune acquisition by the host against important antigens are end points of a long process. Variant genes and proteins of the parasite can exert a role in this process by enbling immune evasion, cytoadherence resulting in the maintainence of the infective process. We tested three experimental approaches focusing on the following points:1-Show if variant BIR antigens are associated with cytoadherence during murine infections 2- The role of a transgene under the control of a variant gene promoter in adaptation to infection in hosts which express or not the transgene 3- Creation of a vaccine model applicable to any relevant antigen in infections with Plasmodium. As results we showed that: 1-BIR antigenes are likely not related to cito adhesion in the murine model. Cytoadherence in this model is probably related to exported parasite proteins with LCCL domains 2-bir promoters can be modulated during infection in hosts which which differ in one unique gene.The effects observed in this case was an increase in parasitemia, anergy and immune tolerance without affecting the morbidity of infection in the host. These effects are apparently mediated by parasite subpopulations producing exosomes that signal from the parasite to the host.3- We generated a system for recombinant protein production where antigens are fused to GPI and then integrated onto liposomes for vaccine usage. The proof of principle was the use of recombinant PfRH5-GPI as vaccine which elicited antibodies with strong blocking activity in P. falciparum cultures. Together we have shown that the host environment is capable of modulating the activity of variant bir gene promoters and that proteoliposomes loaded with relevant malarial antigens such as PfRH5, are potentially protective when used as malaria vaccine

    Evaluation of the vaccine potential of nanoparticles loaded with components of merozoites and schizonts in the murine model of infection with Plasmodium.

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    Malária é uma doença causada por protozoários do gênero Plasmodium que causa um milhão de mortes anualmente. Quase 3 bilhões de pessoas vivem em áreas tropicais de risco de infecção com uma das 5 espécies evidenciando um problema mundial carente de solução imediata. Esse parasita apresenta um potencial para o rápido desenvolvimento de resistências contra os fármacos utilizados em seu tratamento, por isso uma das soluções preconizadas pela Organização Mundial de Saúde é o desenvolvimento de vacinas eficazes para seu controle.O objetivo desse trabalho foca-se no aperfeiçoamento de uma metodologia mais efetiva para a formulação de vacinas contra malária. Inicialmente no modelo roedor, foi utilizado o método de carregamento em nanopartículas lipossomais , com proteínas oriundas de merozoítos do gênero Plasmodium. Além da avaliação do potencial vacinal das nanopartículas (sobrevida/morbidade), avaliamos o efeito da vacina contra toxinas (por exemplo, domínios GPI). Concluímos de maneira concisa que proteolipossomos gerados com proteínas GPI ancoradas do gênero Plasmodium possuem efeitos notáveis em relação a controle de crescimento parasitológico, mostrando-se efetivo também em desafios de letalidade in vivo. No que diz respeito a aspectos que afetam humanos, os soros gerados contra proteínas do parasita são capazes de diminuir interleucinas relacionadas com sintomas graves e parecem ter grandes efeitos antiparasitários que se correlacionam diretamente com o perfil genético do hospedeiro imunizado em ensaios in vitro.Malaria is a tropical disease caused by species of the protozoan Plasmodium and around one million people die of the disease each year, while 3 billion individuals live at risk to acquire infection with one of the five species known to infect humans. Due to the parasite\'s looming resistance against most of the antimalarial compounds used in therapy, the WHO preconizes the development of effective vaccine as an important goal. The purpose of this work was to evaluate the potential of a new method of vaccine formulation against malaria. Initially tested in the rodent model, we loaded liposomal nanostructures with merozoite-derived GPI-anchored proteins. We then monitored parameters such as survival and morbidity after challenge and measured the effect against parasite derived toxines. We observed significant effects in terms of control of parasitemy and in one model complete survival of mice. We also detected the generation of antiGPI antibodies which showed to be functional in decreasing TNF-a production in an in vitro model, however, we detected that this function was dependent on the genetic background of the antibody producing immunized animal

    A DNA Vaccine Encoding Plasmodium falciparum PfRH5 in Cationic Liposomes for Dermal Tattooing Immunization

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    Vaccines are the primary means of controlling and preventing pandemics and outbreaks of pathogens such as bacteria, viruses, and parasites. However, a major drawback of naked DNA-based vaccines is their low immunogenicity and the amount of plasmid DNA necessary to elicit a response. Nano-sized liposomes can overcome this limitation, enhancing both nucleic acid stability and targeting to cells after administration. We tested two different DNA vaccines in cationic liposomes to improve the immunogenic properties. For this, we cloned the coding sequences of the Plasmodium falciparum reticulocyte binding protein homologue 5 (PfRH5) either alone or fused with small the small hepatitis virus (HBV) envelope antigen (HBsAg) encoding sequences, potentially resulting in HBsAg particles displaying PfRH5 on their outside. Instead of invasive intraperitoneal or intramuscular immunization, we employed intradermal immunization by tattooing nano-encapsulated DNA. Mice were immunized with 10 μg encapsulated DNA encoding PfRH5 alone or in fusion with HBsAg and this elicited antibodies against schizont extracts (titer of 104). Importantly, only IgG from animals immunized with PfRH5-HBs demonstrated sustained IgG-mediated inhibition in in vitro growth assays showing 58% and 39% blocking activity after 24 and 48 h, respectively. Intradermal tattoo-vaccination of encapsulated PfRH5-HBsAg coding plasmid DNA is effective and superior compared with an unfused PfRH5-DNA vaccine, suggesting that the HBsAg fusion may be advantageous with other vaccine antigens

    Real time PCR analysis of <i>surf</i> transcription in continuous cultures of <i>P</i>. <i>falciparum</i> NF54.

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    <p>The relative transcript levels were calculated using seryl-tRNA ligase (PF3D7_0717700) as endogenous control (indicated as “K1”). Two cycles before retrieving RNA, parasites were synchronized twice as described and the different stages harvested at identical hours after the final sorbitol lysis. The differently colored bars show the results for 0 (white bars), 20 (grey bars) and 40 reinvasions (black bars). The X axis shows the results for each individual <i>surf</i> gene (nomenclature see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183129#pone.0183129.s002" target="_blank">S1 Table</a>). See Fig A in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183129#pone.0183129.s001" target="_blank">S1 File</a> for similarly obtained results using the 3D7 strain.</p

    Construction of the knockin plasmids and transfectant clone classification by PCR.

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    <p>In <b>A</b>, the proposed model for single crossover recombination of the plasmid pS4-GFP-HA-DD24 is shown. The arrows indicate the localization of oligonucleotides used for PCR. Oligos 3 and 4 amplify the homology region used for the construct. In <b>B</b>, PCR results using genomic DNA of the recombinant parasite clone (NF54::pS4GFPHADD24) and controls (NF54 genomic DNA, transfection plasmid pS4GFPHADD24 and water) employed in the experiments are shown. The primer combinations used in PCRs are indicated below the gel picture. On the left, sizes of the DNA molecular weight standard (in base pairs). In <b>C</b>, the negligible influence of Shield-1 on the growth of wildtype NF54 or transfectant cultures is shown. In <b>D</b>, Fluorescence microscopy with a schizont from the parasite line NF54::pS4GFPHA (upper painels) and NF54::pS4GFPHADD24 with (middle painels) and without 1 μM Shield-1 (lower painel): <b>I</b>, bright field, <b>II</b>, nuclear staining using DAPI, <b>III</b>, GFP-tagged SURFIN4.1 and <b>IV</b>, overlay of <b>I</b> to <b>III</b>.</p
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