Regulatory T Cells Accumulate in the Lung Allergic Inflammation and Efficiently Suppress T-Cell Proliferation but Not Th2 Cytokine Production

Foxp3+CD25+CD4+ regulatory T cells are vital for peripheral tolerance and control of tissue inflammation. In this study, we characterized the phenotype and monitored the migration and activity of regulatory T cells present in the airways of allergic or tolerant mice after allergen challenge. To induce lung allergic inflammation, mice were sensitized twice with ovalbumin/aluminum hydroxide gel and challenged twice with intranasal ovalbumin. Tolerance was induced by oral administration of ovalbumin for 5 consecutive days prior to OVA sensitization and challenge. We detected regulatory T cells (Foxp3+CD25+CD4+ T cells) in the airways of allergic and tolerant mice; however, the number of regulatory T cells was more than 40-fold higher in allergic mice than in tolerant mice. Lung regulatory T cells expressed an effector/memory phenotype (CCR4highCD62LlowCD44highCD54highCD69+) that distinguished them from naive regulatory T cells (CCR4intCD62LhighCD44intCD54intCD69−). These regulatory T cells efficiently suppressed pulmonary T-cell proliferation but not Th2 cytokine production

Regulatory T Cells Accumulate in the Lung Allergic Inflammation and Efficiently Suppress T-Cell Proliferation but Not Th2 Cytokine Production

Foxp3+CD25+CD4+ regulatory T cells are vital for peripheral tolerance and control of tissue inflammation. In this study, we characterized the phenotype and monitored the migration and activity of regulatory T cells present in the airways of allergic or tolerant mice after allergen challenge. To induce lung allergic inflammation, mice were sensitized twice with ovalbumin/aluminum hydroxide gel and challenged twice with intranasal ovalbumin. Tolerance was induced by oral administration of ovalbumin for 5 consecutive days prior to OVA sensitization and challenge. We detected regulatory T cells (Foxp3+CD25+CD4+ T cells) in the airways of allergic and tolerant mice; however, the number of regulatory T cells was more than 40-fold higher in allergic mice than in tolerant mice. Lung regulatory T cells expressed an effector/memory phenotype (CCR4highCD62LlowCD44highCD54highCD69+) that distinguished them from naive regulatory T cells (CCR4intCD62LhighCD44intCD54intCD69−). These regulatory T cells efficiently suppressed pulmonary T-cell proliferation but not Th2 cytokine production

Análise do perfil de citocinas e fatores de crescimento em plasma rico em plaquetas obtido por meio das metodologias do sistema aberto e colunas

Objective: To evaluate growth factors and cytokines in samples of platelet-rich plasma obtained by three different centrifugation methods. Methods: Peripheral blood of six individuals with no hematological diseases, aged 18 to 68 years, was drawn to obtain platelet-rich plasma, using the open method and commercial columns by Medtronic and Biomet. The products obtained with the different types of centrifugation were submitted to laboratory analysis, including pro-inflammatory cytokines and chemokines by flow cytometry assays, the concentration of fibroblast growth factors-2 (FGF-2) and transforming growth factor-beta1 (TGF-beta 1). Results: The diverse separation methods generated systematically different profiles regarding number of platelets and leukocytes. The Medtronic system yielded a product with the highest concentration of platelets, and the open method, with the lowest concentration of platelets. The results of cytokine analysis showed that the different types of centrifugation yielded products with high concentrations of interleukin 8, interleukin 1 beta. The open system resulted in a product with high levels of interleukin 6. Other cytokines and chemokines measured were similar between systems. The product obtained with the open method showed higher levels of TGF-beta 1 in relation to other systems and low FGF-2 levels. Conclusion: The formed elements, growth factors and cytokines in samples of platelet-rich plasma varied according to the centrifugation technique used.Objetivo: Avaliar fatores de crescimento e citocinas em amostras de plasma rico em plaquetas obtidas por três diferentes métodos de centrifugação. Métodos: Foi coletado sangue periférico de seis indivíduos, sem doença hematológica, com idades entre 18 e 68 anos, para obtenção de plasma rico em plaquetas, utilizando o método aberto e sistemas comerciais das empresas Medtronic e Biomet. Os produtos obtidos com os diferentes tipos de centrifugação foram submetidos às análises laboratoriais, incluindo citocinas próinflamatórias e quimiocinas, por meio de ensaios de citometria de fluxo, concentração do fator de crescimento fibroblástico-2 (FGF-2) e fator de crescimento transformador-beta1 (TGF-β1). Resultados: As diferentes centrifugações geraram perfis sistematicamente diferentes referentes ao número de plaquetas e de leucócitos. O sistema da Medtronic originou produto com a maior concentração de plaquetas, e o método aberto com a menor concentração de plaquetas. Os resultados da análise de citocinas demonstraram que os diferentes tipos de centrifugação originaram produtos com elevadas concentrações de interleucina 8 e interleucina 1β. O sistema aberto resultou em produto com elevados níveis de interleucina 6. As demais citocinas e quimiocinas mensuradas foram similares entre os sistemas. O produto obtido com o método aberto apresentou níveis superiores de TGF-β1 em relação aos demais sistemas e reduzidos níveis de FGF-2. Conclusão: Os elementos figurados, fatores de crescimento e citocinas, em amostras de plasma rico em plaquetas, variaram conforme a técnica de centrifugação utilizada.Univ Fed Sao Paulo, Escola Paulista Med, Sao Paulo, SP, BrazilHosp Israelita Albert Einstein, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, SP, BrazilWeb of Scienc

The Spleen CD4+ T Cell Response to Blood-Stage Plasmodium chabaudi Malaria Develops in Two Phases Characterized by Different Properties

The pivotal role of spleen CD4+ T cells in the development of both malaria pathogenesis and protective immunity makes necessary a profound comprehension of the mechanisms involved in their activation and regulation during Plasmodium infection. Herein, we examined in detail the behaviour of non-conventional and conventional splenic CD4+ T cells during P. chabaudi malaria. We took advantage of the fact that a great proportion of CD4+ T cells generated in CD1d-/- mice are I-Ab-restricted (conventional cells), while their counterparts in I-Ab-/- mice are restricted by CD1d and other class IB major histocompatibility complex (MHC) molecules (non-conventional cells). We found that conventional CD4+ T cells are the main protagonists of the immune response to infection, which develops in two consecutive phases concomitant with acute and chronic parasitaemias. The early phase of the conventional CD4+ T cell response is intense and short lasting, rapidly providing large amounts of proinflammatory cytokines and helping follicular and marginal zone B cells to secrete polyclonal immunoglobulin. Both TNF-α and IFN-γ production depend mostly on conventional CD4+ T cells. IFN-γ is produced simultaneously by non-conventional and conventional CD4+ T cells. The early phase of the response finishes after a week of infection, with the elimination of a large proportion of CD4+ T cells, which then gives opportunity to the development of acquired immunity. Unexpectedly, the major contribution of CD1d-restricted CD4+ T cells occurs at the beginning of the second phase of the response, but not earlier, helping both IFN-γ and parasite-specific antibody production. We concluded that conventional CD4+ T cells have a central role from the onset of P. chabaudi malaria, acting in parallel with non-conventional CD4+ T cells as a link between innate and acquired immunity. This study contributes to the understanding of malaria immunology and opens a perspective for future studies designed to decipher the molecular mechanisms behind immune responses to Plasmodium infection

First report of olive leaf scorch in Brazil, associated with Xylella fastidiosa subsp. pauca

Olea europaea (L.) trees displaying leaf scorching symptoms, identical to those recently reported for olive trees colonized by Xylella fastidiosa in Southern Italy and also in Argentina, were observed in commercial orchards of two counties in Southeastern Brazil. PCR-based diagnosis using conserved primers for X. fastidiosa strains (RST31/33) and also specific to X. fastidiaosa subsp. pauca (CVC1/272-2 int) were positive for all symptomatic tested samples (n = 8 of 9), but no template was obtained using twigs from asymptomatic trees (n = 20). Bacterial colonies were isolated from symptomatic tissues on culture medium and confirmed by PCR using the set of primers specific to X. fastidiosa subsp. pauca. Comparative sequence analyses of seven MLST loci amplified from one tripled passaged colony (MFG01) perfectly matched with sequences of alleles leuA #7, petC #6, malF#8, cysG#10, holC#11, nuoL#8, and gltT#8, the allelic profile of Sequence Type-ST16, which is represented by the strain COF0238 isolated from Coffea arabica (L.) in Brazil (http://pubmlst.org/xfastidiosa/). Phylogenetic analysis placed the ST16 into subspecies pauca, but genetically closer to ST11 and ST13, both obtained from Citrus sinensis (L.) trees with citrus variegated chlorosis. The results confirm the association of olive plants showing leaf scorching with the presence of X. fastidiosa subsp. pauca , and represent the first report of this bacterium in Brazilian olive orchards

Kahoot: o uso de tecnologia digital para a aprendizagem de biologia celular no Ifma-Campus Barrerinhas / Kahoot: the use of digital technology to learn cell biology in Ifma-Campus Barrerinhas

Os novos instrumentos tecnológicos são importantes para o ambiente educacional da atualidade, tendo em vista que o surgimento da tecnologia e o aumento do uso dos dispositivos móveis (smartphone, notebook, tablete) torna-se necessária uma mudança no processo de ensino e aprendizagem com a inclusão da tecnologia em sala de aula. O presente artigo tem como objetivo principal ratificar se o aplicativo Kahoot pode contribuir para a aprendizagem dos conteúdos da cadeira de Biologia Celular no Ensino Superior. As novas tecnologias da informação e comunicação na prática pedagógica pode ser utilizadas como recurso pelo professor de forma a contribuir efetivamente no processo de aprendizagem, porquanto, os recursos tecnológicos auxiliam no processo de ensino e aprendizagem. Os materiais usados nesta pesquisa foram: Kahoot, folhas A4, impressora, celulares e notebook dos alunos e os procedimentos foram: aplicação do quiz virtual, dois questionários, sendo um com questões sobre Biologia Celular e outro sobre a usabilidade do aplicativo supracitado. A maioria dos alunos acertaram as questões envolvendo Citoplasma celular, e afirmaram que o aplicativo Kahoot contribuiu para o processo de aprendizagem sobre o referido conteúdo na disciplina supracitada. Isso comprova que o aplicativo em questão pode auxiliar no processo de aprendizagem dos educandos, vez que se trona um instrumento alternativo para a metodologia dos professores. 

Avaliação da marcação de células-tronco mesenquimais de cordão umbilical com nanopartículas superparamagnéticas de óxido de ferro recobertas com Dextran e complexadas a Poli-L-Lisina

OBJECTIVE: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. METHODS: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37°C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxy-fluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. RESULTS: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine continue to proliferate over seven days and the percentage of cells in early or late apoptosis is low compared to the percentage of live cells over the three days. CONCLUSION: Our results showed that the use of poly-L-lysine complexed with superparamagnetic iron oxide nanoparticles/dextran provides better internalization of these superparamagnetic iron oxide nanoparticles in mesenchymal stem cells Thus, we demonstrated that this type of labeling is not cytotoxic to the mesenchymal stem cells, since the viability and apoptosis assays showed that the cells remain alive and proliferating. The efficiency of this type of labeling in mesenchymal stem cells can provide non-invasive methods for monitoring these cells in vivo.OBJETIVO: O objetivo deste estudo foi avaliar o efeito da marcação de células-tronco mesenquimais obtidas da parede da veia do cordão umbilical com nanopartículas de óxido de ferro superparamagnéticas recobertas com dextran e complexadas a um agente transfector não viral denominado de Poli-L-Lisina. MÉTODOS: A marcação das células-tronco mesenquimais foi realizada utilizando as nanopartículas de óxido de ferro superparamagnéticas recobertas com dextran complexadas e não complexadas a Poli-L-Lisina. As nanopartículas de óxido de ferro superparamagnéticas recobertas com dextran foram incubadas com o Poli-L-Lisina em um sonicador ultrassonico a 37ºC por 10 minutos, para a formação do complexo através de interação eletrostática. Em seguida, as células-tronco mesenquimais foram incubadas overnight com as nanopartículas de óxido de ferro superparamagnéticas complexadas e não com Poli-L-Lisina. Após o período de incubação as células-tronco mesenquimais foram avaliadas quanto à internalização do complexo nanopartícula de óxido de ferro superparamagnéticas /dextran/Poli-L-Lisina e nanopartícula de óxido de ferro superparamagnéticas /dextran através de ensaio citoquímico com azul de prússia. A viabilidade celular das células-tronco mesenquimais marcadas foi avaliada através do ensaio de proliferação celular utilizando o método de 5,6-carboxy-fluorescein-succinimidyl-ester e de morte celular através do método de anexina-iodeto de propídeo, ambos utilizando o recurso de citometria de fluxo. RESULTADOS: Observamos nos ensaios citoquímicos que as células-tronco mesenquimais que foram marcadas com as nanopartícula de óxido de ferro superparamagnéticas /dextran sem a Poli-L-Lisina, não internalizaram com eficiência as nanopartículas devido pouca detecção de sua presença no interior das células. As células-tronco mesenquimais marcadas com o complexo nanopartícula de óxido de ferro superparamagnéticas /dextran/Poli-L-Lisina internalizaram com eficiência as nanopartículas devido à maior presença destas no interior das células. Os ensaios de viabilidade e morte celular demonstraram respectivamente que as células-tronco mesenquimais marcadas com as nanopartícula de óxido de ferro superparamagnéticas /dextran/Poli-L-Lisina continuam proliferando ao longo de sete dias e a porcentagem de células em apoptose inicial e tardia é baixa em relação à porcentagem de células vivas ao longo de três dias. CONCLUSÃO: Evidenciamos através de nossos resultados a necessidade da utilização da Poli-L-Lisina complexada com a nanopartícula de óxido de ferro superparamagnéticas /dextran para melhor internalização nas células-tronco mesenquimais. Paralelamente, demonstramos que este tipo de marcação não é citotóxico para as células-tronco mesenquimais já que os testes de morte e viabilidade celular mostraram que as células continuam vivas e proliferando

The Liver Plays a Major Role in Clearance and Destruction of Blood Trypomastigotes in Trypanosoma cruzi Chronically Infected Mice

Intravenous challenge with Trypanosoma cruzi can be used to investigate the process and consequences of blood parasite clearance in experimental Chagas disease. One hour after intravenous challenge of chronically infected mice with 5×106 trypomastigotes, the liver constituted a major site of parasite accumulation, as revealed by PCR. Intact parasites and/or parasite remnants were visualized at this time point scattered in the liver parenchyma. Moreover, at this time, many of liver-cleared parasites were viable, as estimated by the frequency of positive cultures, which considerably diminished after 48 h. Following clearance, the number of infiltrating cells in the hepatic tissue notably increased: initially (at 24 h) as diffuse infiltrates affecting the whole parenchyma, and at 48 h, in the form of large focal infiltrates in both the parenchyma and perivascular spaces. Phenotypic characterization of liver-infiltrating cells 24 h after challenge revealed an increase in Mac1+, CD8+ and CD4+ cells, followed by natural killer (NK) cells. As evidence that liver-infiltrating CD4+ and CD8+ cells were activated, increased frequencies of CD69+CD8+, CD69+CD4+ and CD25+CD122+CD4+ cells were observed at 24 and 48 h after challenge, and of CD25−CD122+CD4+ cells at 48 h. The major role of CD4+ cells in liver protection was suggested by data showing a very high frequency of interferon (IFN)-γ-producing CD4+ cells 24 h after challenge. In contrast, liver CD8+ cells produced little IFN-γ, even though they showed an enhanced potential for secreting this cytokine, as revealed by in vitro T cell receptor (TCR) stimulation. Confirming the effectiveness of the liver immune response in blood parasite control during the chronic phase of infection, no live parasites were detected in this organ 7 days after challenge

Physical activity levels during COVID-19 pandemic and its associated factors in patients with Chagas disease

BackgroundA better understanding of the consequences of the Coronavirus Disease 2019 (COVID-19) pandemic on lifestyle of patients with Chagas disease (ChD) is of paramount importance to facilitate the implementation of intervention strategies tailored to this specific population.ObjectiveThe present study aimed to evaluate the level of physical activity (PA) in Chagas disease (ChD) patients during the Coronavirus Disease 2019 (COVID-19) pandemic and its main associated factors.MethodsThis is a cross-sectional study with 187 patients of both sexes, aged ≥18 years, followed in a national infectious disease center (Rio de Janeiro, Brazil). The level of PA was determined by the International Physical Activity Questionnaire short version and expressed in terms of total volume of physical activity (PA) (MET-minutes per week). Individuals were classified as physically active following the 2020 World Health Organization PA guideline. The exposure variables were age, sex, race, marital status, schooling, income per capita, number of rooms per domicile, number of residents per domicile, body mass index, clinical form of ChD, COVID-19 antibodies, comorbidities, self-reported anxiety, self-reported depression, self-reported fear, and self-reported sadness. The association between the exposure variables with total PA (as a continuous variable) was determined using univariate and multivariate linear regression models.ResultsMean age was 61.1 ± 11.6 years. Most (62%) were women and self-declared their race as mixed (50.8%). The percentage of physically active individuals according to was 52%. The variables independently associated with total PA levels were non-white race (Exp β = 1.39; 95% CI 1.02 to 1.90), dyslipidemia (Exp β = 0.73; 95% CI 0.56 to 0.95) and self-reported depression during quarantine (Exp β = 0.71; 95% CI 0.52 to 0.96).ConclusionNon-white race was positively associated with total levels of PA, while dyslipidemia, and self-reported depression during quarantine were negatively associated with total levels of PA. The identification of associated factors can facilitate the development of tailored strategies to increase PA levels ChD patients

Diretriz da Sociedade Brasileira de Cardiologia sobre Diagnóstico e Tratamento de Pacientes com Cardiomiopatia da Doença de Chagas

This guideline aimed to update the concepts and formulate the standards of conduct and scientific evidence that support them, regarding the diagnosis and treatment of the Cardiomyopathy of Chagas disease, with special emphasis on the rationality base that supported it.  Chagas disease in the 21st century maintains an epidemiological pattern of endemicity in 21 Latin American countries. Researchers and managers from endemic and non-endemic countries point to the need to adopt comprehensive public health policies to effectively control the interhuman transmission of T. cruzi infection, and to obtain an optimized level of care for already infected individuals, focusing on diagnostic and therapeutic opportunistic opportunities.   Pathogenic and pathophysiological mechanisms of the Cardiomyopathy of Chagas disease were revisited after in-depth updating and the notion that necrosis and fibrosis are stimulated by tissue parasitic persistence and adverse immune reaction, as fundamental mechanisms, assisted by autonomic and microvascular disorders, was well established. Some of them have recently formed potential targets of therapies.  The natural history of the acute and chronic phases was reviewed, with enhancement for oral transmission, indeterminate form and chronic syndromes. Recent meta-analyses of observational studies have estimated the risk of evolution from acute and indeterminate forms and mortality after chronic cardiomyopathy. Therapeutic approaches applicable to individuals with Indeterminate form of Chagas disease were specifically addressed. All methods to detect structural and/or functional alterations with various cardiac imaging techniques were also reviewed, with recommendations for use in various clinical scenarios. Mortality risk stratification based on the Rassi score, with recent studies of its application, was complemented by methods that detect myocardial fibrosis.  The current methodology for etiological diagnosis and the consequent implications of trypanonomic treatment deserved a comprehensive and in-depth approach. Also the treatment of patients at risk or with heart failure, arrhythmias and thromboembolic events, based on pharmacological and complementary resources, received special attention. Additional chapters supported the conducts applicable to several special contexts, including t. cruzi/HIV co-infection, risk during surgeries, in pregnant women, in the reactivation of infection after heart transplantation, and others.     Finally, two chapters of great social significance, addressing the structuring of specialized services to care for individuals with the Cardiomyopathy of Chagas disease, and reviewing the concepts of severe heart disease and its medical-labor implications completed this guideline.Esta diretriz teve como objetivo principal atualizar os conceitos e formular as normas de conduta e evidências científicas que as suportam, quanto ao diagnóstico e tratamento da CDC, com especial ênfase na base de racionalidade que a embasou. A DC no século XXI mantém padrão epidemiológico de endemicidade em 21 países da América Latina. Investigadores e gestores de países endêmicos e não endêmicos indigitam a necessidade de se adotarem políticas abrangentes, de saúde pública, para controle eficaz da transmissão inter-humanos da infecção pelo T. cruzi, e obter-se nível otimizado de atendimento aos indivíduos já infectados, com foco em oportunização diagnóstica e terapêutica. Mecanismos patogênicos e fisiopatológicos da CDC foram revisitados após atualização aprofundada e ficou bem consolidada a noção de que necrose e fibrose sejam estimuladas pela persistência parasitária tissular e reação imune adversa, como mecanismos fundamentais, coadjuvados por distúrbios autonômicos e microvasculares. Alguns deles recentemente constituíram alvos potenciais de terapêuticas. A história natural das fases aguda e crônica foi revista, com realce para a transmissão oral, a forma indeterminada e as síndromes crônicas. Metanálises recentes de estudos observacionais estimaram o risco de evolução a partir das formas aguda e indeterminada e de mortalidade após instalação da cardiomiopatia crônica. Condutas terapêuticas aplicáveis aos indivíduos com a FIDC foram abordadas especificamente. Todos os métodos para detectar alterações estruturais e/ou funcionais com variadas técnicas de imageamento cardíaco também foram revisados, com recomendações de uso nos vários cenários clínicos. Estratificação de risco de mortalidade fundamentada no escore de Rassi, com estudos recentes de sua aplicação, foi complementada por métodos que detectam fibrose miocárdica. A metodologia atual para diagnóstico etiológico e as consequentes implicações do tratamento tripanossomicida mereceram enfoque abrangente e aprofundado. Também o tratamento de pacientes em risco ou com insuficiência cardíaca, arritmias e eventos tromboembólicos, baseado em recursos farmacológicos e complementares, recebeu especial atenção. Capítulos suplementares subsidiaram as condutas aplicáveis a diversos contextos especiais, entre eles o da co-infecção por T. cruzi/HIV, risco durante cirurgias, em grávidas, na reativação da infecção após transplante cardíacos, e outros.    Por fim, dois capítulos de grande significado social, abordando a estruturação de serviços especializados para atendimento aos indivíduos com a CDC, e revisando os conceitos de cardiopatia grave e suas implicações médico-trabalhistas completaram esta diretriz.&nbsp