This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Thymic stromal lymphopoietin (TSLP) is a functionally pleotropic cytokine important in immune regulation, and TSLP dysregulation is associated with numerous diseases. TSLP is produced by many cell types, but has predominantly been characterized as a secreted factor from epithelial cells which activates dendritic cells (DC) that subsequently prime T helper (TH) 2 immunity. However, DC themselves make significant amounts of TSLP in response to microbial products, but the functional role of DC-derived TSLP remains unclear. We show that TSLPR signaling negatively regulates IL-1β production during dectin-1 stimulation of human DC. This regulatory mechanism functions by dampening Syk phosphorylation and is mediated via NADPH oxidase-derived ROS, HIF-1α and pro-IL-1β expression. Considering the profound effect TSLPR signaling has on the metabolic status and the secretome of dectin-1 stimulated DC, these data suggest that autocrine TSLPR signaling could have a fundamental role in modulating immunological effector responses at sites removed from epithelial cell production of TSLP.

Dectin-1/CLEC7A is a pattern recognition receptor that recognizes β-1,3 glucans, and its stimulation initiates signaling events characterized by the production of inflammatory cytokines from human dendritic cells (DCs) required for antifungal immunity. β-glucans differ greatly in size, structure, and ability to activate effector immune responses from DC; as such, small particulate β-glucans are thought to be poor activators of innate immunity. We show that β-glucan particle size is a critical factor contributing to the secretion of cytokines from human DC; large β-glucan-stimulated DC generate significantly more IL-1β, IL-6, and IL-23 compared to those stimulated with the smaller β-glucans. In marked contrast, the secretion of TSLP and CCL22 were found to be insensitive to β-glucan particle size. Furthermore, we show that the capacity to induce phagocytosis, and the relative IL-1β production determined by β-glucan size, regulates the composition of the cytokine milieu generated from DC. This suggests that β-glucan particle size is critically important in orchestrating the nature of the immune response to fungi.

β-Glucans are known for their ability to trigger both protective and damaging immune responses. Here we have explored the role of the beta-glucan receptor Dectin-1 in archetypical models of protective and non-protective immunomodulation induced by beta-glucan rich ligands. In the first model, we explored the role of Dectin-1 in the ability of soluble purified β-glucans to mediate protection against systemic Staphylococcus aureus infection in mice. In the second model, we explored the role of Dectin-1 in zymosan induced multiple organ dysfunction syndrome. In both cases, these β-glucan rich compounds had marked effects invivo which were unaltered by Dectin-1 deficiency, suggesting that this receptor has a redundant role in these murine models.

β-Glucans are known for their ability to trigger both protective and damaging immune responses. Here we have explored the role of the beta-glucan receptor Dectin-1 in archetypical models of protective and non-protective immunomodulation induced by beta-glucan rich ligands. In the first model, we explored the role of Dectin-1 in the ability of soluble purified β-glucans to mediate protection against systemic Staphylococcus aureus infection in mice. In the second model, we explored the role of Dectin-1 in zymosan induced multiple organ dysfunction syndrome. In both cases, these β-glucan rich compounds had marked effects invivo which were unaltered by Dectin-1 deficiency, suggesting that this receptor has a redundant role in these murine models.

Candida albicans is an increasingly important pulmonary fungal pathogen. Resident alveolar macrophages are important in host defense against opportunistic fungal infections. Activation of Group IVA cytosolic phospholipase A2α (cPLA2α) in macrophages initiates arachidonic acid (AA) release for production of eicosanoids, which regulate inflammation and immune responses. We investigated the ability of C. albicans to activate cPLA2α in unprimed alveolar macrophages and after priming with granulocyte macrophage colony-stimulating factor (GM-CSF), which regulates alveolar macrophage maturation. AA was released within minutes by GM-CSF-primed but not unprimed alveolar macrophages in response to C. albicans, and was blocked by soluble glucan phosphate (S-GP). The expression of the β-glucan receptor dectin-1 was increased in GM-CSF-primed macrophages, and AA release from GM-CSF-primed dectin-1-/- alveolar macrophages was reduced to basal levels. The enhanced activation of extracellular signal-regulated kinases and phosphorylation of cPLA2α on Ser-505 that occurred in GM-CSF-primed macrophages were reduced by MEK1 and Syk inhibitors, which also suppressed AA release. At later times after C. albicans infection (6 h), unprimed and GM-CSF-primed macrophages released similar levels of AA. The expression of cyclooxygenase 2 and prostanoid production at 6 hours was higher in GM-CSF-primed macrophages, but the responses were not dependent on dectin-1. However, dectin-1 contributed to the C. albicans-stimulated increase in TNF-α production that occurred in GM-CSF-primed macrophages. The results demonstrate that dectin-1 mediates the acute activation of cPLA 2α in GM-CSF-primed alveolar macrophages, but not in the more delayed phase of AA release and GM-CSF-dependent prostanoid production.

β-Glucans are structural components of fungal cell walls which are involved in the immune recognition of fungal pathogens and possess beneficial immunomodulatory activities in isolated form. Here we have developed a soluble chimeric form of the major mammalian β-glucan receptor, Dectin-1, and demonstrate its application for the detection and characterisation of soluble and insoluble β-glucans, including fungal particles, using ELISA, flow cytometric and fluorescence-based microscopy assays.

An estimated 45% of all deaths can be attributed to various chronic fibroproliferative diseases. Idiopathic pulmonary fibrosis (IPF) is the most common form of interstitial lung disease which is characterized by progressive decline in lung function. While the pathogenesis of IPF is not fully understood, alternatively activated macrophages (M2) have been implicated as a key contributor to the fibrotic process. The plasticity of macrophages in vivo challenges the ability to specifically target the M2 macrophage phenotype across species. Previous bioinformatic analysis from our lab identified Dectin-1/Clec7a as a unique marker of M2 macrophages in both human and murine model systems. The expression of the transmembrane receptor Dectin-1 has not been elucidated in the context of pulmonary fibrosis. To prevent the progression of fibrosis by targeting alternatively activated macrophages, we investigated the expression of Dectin-1 in IPF and an experimental model of fibrotic lung disease. Our data demonstrated that while protein expression of Dectin-1 was increased in archived lung tissues of patients with IPF, mRNA expression of this receptor was downregulated in the tissues of these IPF patients. Gene expression of Dectin-1 was shown to be increased in monocyte-derived macrophages, further suggesting a circulatory component contributing to lung fibrosis. As expected, we confirmed that Dectin-1 was highly expressed past the injury phase of the bleomycin-model of induced pulmonary fibrosis which aligns with the increased immune infiltrates at this time point. Preliminary work into the time dependency of the resolution phase of the bleomycin-induced model of lung fibrosis was shown. All in all, our data suggests that Dectin-1 may be a useful marker in characterizing and differentiating phenotypes of macrophages implicated in the fibrotic process. Future efforts aim to gain insight into the functional requirement of Dectin-1 in the alternative activation of profibrotic macrophages to identify novel therapeutic targets for fibrotic lung disease. / Thesis / Master of Science (MSc)

Orientador: Antonio Condino Neto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T22:05:12Z (GMT). No. of bitstreams: 1 Talero_LuisAlbertoPedroza_D.pdf: 1538530 bytes, checksum: 6dc94ec71cdd6f03d096be015a2b1757 (MD5) Previous issue date: 2009 / Resumo: A Poliendocrinopatia autoimune associada a candidíase e distrofia ectodérmica (APECED) é um síndrome caracterizado pela presença de pelo menos dois sintomas clínicos, endocrinopatia autoimune, sendo que as mais comuns são hipoparatiroidismo, doença de Addison, além de candidíase mucocutânea crônica. É também comum nos pacientes o desenvolvimento de distrofia ectodérmica, como distrofia nas unhas ou alopécia. O APECED é produzido por mutações no gene AIRE, que codifica uma proteína com propriedades reguladoras na transcrição de proteínas ectópicas no timo, o que estaria envolvido na seleção negativa de células T auto-reativas, e conseqüentemente no desenvolvimento da doença autoimune. No entanto a associação da deficiência da proteína AIRE com a suscetibilidade a candidíase ou a distrofia ectodérmica permanecem obscuras. No presente trabalho, investigamos a possibilidade que esta associação esteja envolvida com a expressão e função da proteína AIRE no ambiente extra-tímico. Usando células de sangue periférico de pacientes com mutações no AIRE, e a técnica de SiRNA para silenciar este gene em células de linhagem mielomonocítica THP-1, demonstramos que a proteína AIRE é importante para a resposta via KF-kB dos TLRs e Dectina-1, sendo que AIRE está presente num complexo com Dectina-1, Syk e Card-9, formado após o estímulo com Curdlan. Além disso demonstramos que a formação deste complexo pode acontecer no citoplasma ou membrana citoplasmática, uma vez que após este estímulo, a proteína AIRE é exportada do núcleo permanecendo temporariamente na membrana. Finalmente usando a técnica de espectroscopia de massa e microscopia confocal, mostramos que AIRE interage com a proteína Queratina 17, tanto em células THP-1 como em células HaCaT (linhagem de queratinócitos), quando as células entram num estágio de espraiamento e migração. Assim, a presença da proteína AIRE na via de sinalização da Dectina-1, pode estar relacionada com a susceptibilidade a infecções crônicas por C. albicans observada nestes pacientes. A resposta imune via Dectina-1 é importante na resposta a este fungo e defeitos na molécula CARD9 e Dectina-1 podem estar associados a Candidíase mucocutânea crônica. Por outro lado, a descrição da associação de AIRE com K17 pode ser relevante, já que pacientes com mutações no gene que codifica para a proteína K17 desenvolvem uma doença chamada paquioníquia congênita, caracterizada por distrofia das unhas e alopécia, características clínicas observadas também nos pacientes com APECED. Deste modo, neste trabalho apresentamos evidências que apontam para um novo papel funcional da proteína AIRE no ambiente extratímico, que poderia explicar em parte algumas características clínicas dos pacientes com APECED, como a elevada suscetibilidade a infecções por C. albicans, e a distrofia ectodérmica / Abstract: The autoimmune polyendocrinopathy candidiasis and ectodermal dystrophy (APECED) is characterized by the presence of two from three major clinical symptoms: Addison's disease, and/or hypoparathyroidism, and/or chronic mucocutaneous candidiasis. These patients develop also ectodermal dystrophies like nail dystrophy and alopecia. APECED is caused by mutations in the autoimmune regulator gene (AIRE). This gene encodes a protein with DNA binding capacity that can transcriptionally modulate ectopic peripheral tissue antigen (PTA) expression in the thymus, facilitating T cell negative selection. Defects in AIRE may be related with the development of multipleendocrine failure of autoimmune origin in patients with APECED. In spite of this, the role of AIRE deficiency in the C. albicans susceptibility or ectodermal dystrophy, common features in APECED patients, remains to be elucidated. In the present work we explored the hypothesis that candidiasis and ectodermal dystrophy are associated with the extra-thymic role of AIRE. For this we used peripheral blood mononuclear cells from APECED patients, and also THP-1 cells treated with SiRNA for AIRE gene to obtain AIRE deficient cells. We demonstrated that AIRE is required for Dectin-1- and TLR-ligand-induced inflammatory response and complexes with Dectin-1, Syk, and CARD9 after Curdlan stimulation. In addition, we showed that this complex formation takes place outside the nucleus, once that after Curdlan stimulation AIRE seems to be exported to the cytoplasm and transiently locate at the cytoplasmic membrane. Finally using mass spectra and confocal microscopy, we showed an interaction between AIRE and the intermediate filament protein Keratin-17, in both THP-1 cells and the keratinocyte cell line HaCaT. Therefore, the presence of AIRE protein in Dectin-1 pathway seems to be important on the C. albicans response, and the absence of this protein could be a risk factor important for developing candidiasis, commonly observed in APECED patients. This observation is supported by the fact that Dectin-1 is important for C albicans response, and also the recently description of mutations in Dectin-1 and CARD9 and its association with chronic mucocutaneous candidiasis. On the other hand, the description of AIRE and K17 association is important, since patients with defects on K17 gene develop congenital pachyonychia, a disease characterized by nail dystrophy and alopecia, also observed in APECED patients. Thus we provided evidence for a new role of AIRE protein in the extrathymic environment, which in may explain, at least in part, some of the common clinical features other than autoimmunity, observed in APECED patients / Doutorado / Saude da Criança e do Adolescente / Doutor em Saude da Criança e do Adolescente

Les ß-glucanes (BG) sont les polysaccharides les plus abondants de la paroi de Saccharomyces cerevisiae. Depuis des millénaires, ils sont utilisés pour leurs propriétés immunostimulantes et leurs potentiels thérapeutiques. L'objectif de ce travail était de caractériser la réponse immunitaire induite par les BG et de comprendre leurs modes d'action sur les macrophages murins en contexte infectieux. Nous avons montré que (i) les extraits de paroi enrichis en BG n'induisent qu'une faible production de cytokines par les macrophages contrairement aux extraits bruts, (ii) la réponse inflammatoire médiée par les extraits bruts résulte de la signalisation des TLRs et non de Dectin-1 et (iii) les BG stimulent la synthèse tardive de GM-CSF via Dectin-1. En conditions infectieuses, les BG enrichis confèrent une forte signature inflammatoire aux macrophages prétraités conduisant à l'amplification de la production cytokinique, à la synthèse de ROS et l'optimisation de la clairance bactérienne. En conclusion, cette étude souligne les enjeux de l'utilisation des BG enrichis comme adjuvants dans l'amélioration de la résistance des individus aux infections. / ß-glucans (BG) are the most abundant polysaccharides of the Saccharomyces cerevisiae cell wall. For decades, they have been extensively used because of their immuno-modulatory properties and their potential therapeutic effects. The aim of this study was to characterize the immune response induced by BG and to understand their mechanisms of action on murine macrophages occurring upon bacterial infections. We demonstrated that (i) BG-enriched extracts trigger low amounts of cytokine production in contrast with crude products, (ii) the immune response mediated by crude extracts results from TLRs and not from Dectin-1 signaling and (iii) BG-enriched compounds stimulate the late and strong induction of GM-CSF in a Dectin-1-dependent manner. Upon bacteria exposure, BG-enriched extracts confer a strong inflammatory to pretreated macrophages leading to synergistic increase of cytokine release, ROS production and better clearance of pathogens. Altogether, our findings emphasize the relevancy of using BG-enriched extracts for the design of novel adjuvant formulations contributing to individuals' resistance to infections.

Submitted by admin tede (tede@pucgoias.edu.br) on 2017-04-27T14:24:41Z No. of bitstreams: 1 DAIANE DE OLIVEIRA CUNHA.pdf: 2074632 bytes, checksum: 76e82c4169a9d294dcddcc8e9ad849cb (MD5) / Made available in DSpace on 2017-04-27T14:24:41Z (GMT). No. of bitstreams: 1 DAIANE DE OLIVEIRA CUNHA.pdf: 2074632 bytes, checksum: 76e82c4169a9d294dcddcc8e9ad849cb (MD5) Previous issue date: 2017-03-13 / The present dissertation was constructed in the form of scientific articles, being constituted by two articles. The first one, titled "Epidemiological evaluation of patients submitted to the serum galactomannan test with suspected Aspergillosis Invasive", aimed to evaluate the incidence of Invasive Aspergillosis in patients with hematological diseases followed at a reference hospital in Goiânia, Goiás, Brazil. Determine the main factors that contribute to the development of the disease. For this, 1367 samples of 264 patients with malignant hematological diseases treated in the Hematology Sector of Hospital Araújo Jorge, who underwent galactomannan detection, were evaluated in the period from 2013 to 2015, and were excluded patients who had no clinical data in Medical records and loss of follow-up at the hospital. Among the data obtained through the present study it was observed that the mean age was 43.7 years, where 55.5% were male. Of the total number of patients evaluated, 133 performed BMT, 38.9% of which were autologous and 17.9% of the allogeneic type. According to the classification for Invasive Aspergillosis according to the European Organization for Research and Treatment of Cancer, the disease was interpreted as proven in 7.3%, defined by culture positive for the fungus, 6.4% as probable by the detection of galactomannan in the Blood and presence of pulmonary infiltrates and 5.1% as possible by radiological alterations suggestive of Invasive Aspergillosis and galactomannan negative. The estimated / probable / probable Aspergillosis Invasive mortality rate was 61.3% and showed that the disease was significantly associated with the risk of death (p <0.0001). When considering the high mortality rate caused by the development of Aspergillosis Invasive and the fact that an early therapy promotes a significant improvement in the prognosis of patients, we conclude that the detection of galactomannan, performed as a follow-up of patients at high risk of developing the disease, can Be considered an effective method to aid in the identification of Invasive Aspergillosis. The second article entitled "Association between polymorphisms of genes encoding Dectin-1 and Toll-like cellular receptors and susceptibility to Invasive Aspergillosis", aimed to describe the polymorphisms in genes encoding Dectin-1 and Tolllike receptors, Seeking possible associations with the individual susceptibility to Invasive Aspergillosis. This study used as a methodological basis a systematic review of the literature and as a database to PubMed and PMC of the NCBI. The keywords used were: Invasive aspergillosis, polymorphism, Dectin-1 and Toll-like. From this search, 415 studies were found and according to the inclusion and exclusion criteria 8 studies were selected. With the accomplishment of this, it was verified that several are the studies that describe the single base polymorphisms with a greater susceptibility to the Invasive Aspergillosis. The major ones are in genes encoding Toll-like receptors and those that encode cytokines and chemokines (Dectin-1). Thus, it can be observed that, according to studies already carried out, there is a significant association of genetic polymorphisms with Aspergillosis Invasive, but more extensive studies must be performed to obtain more reliable results. In general, we conclude with this dissertation that the development of Invasive Aspergillosis is associated with several factors, one of them being genetic, and that, due to the high mortality rates caused by Invasive Aspergillosis, the detection of galactomannan is of fundamental importance for the Treatment of patients who are more likely to develop the disease, mainly aiding in the prognosis and early diagnosis of it. / A presente dissertação foi construída na modalidade de artigos científicos, sendo constituída por dois artigos. O primeiro, intitulado “Avaliação epidemiológica de pacientes submetidos ao teste de galactomanana sérica com suspeita de Aspergilose Invasiva”, teve como objetivo avaliar a incidência de Aspergilose Invasiva em pacientes com doenças hematológicas acompanhadas em um hospital de referência de Goiânia, Goiás, Brasil, e determinar os principais fatores que contribuem para o desenvolvimento da doença. Para isso, foram avaliadas 1367 amostras de 264 pacientes com doenças hematológicas malignas tratadas no Setor de Hematologia do Hospital Araújo Jorge, os quais realizaram exame de detecção de galactomanana, no período de 2013 a 2015, e foram excluídos pacientes que não possuíam dados clínicos em prontuários e com perda de seguimento no hospital. Dentre os dados alcançados por meio do presente estudo observou-se que a média de idade foi de 43,7 anos, onde 55,5% eram pertencentes ao sexo masculino. Do total de pacientes avaliados, 133 realizaram TMO, sendo que 38,9% eram do tipo autólogo e 17,9% do tipo alogênico. De acordo com a classificação para Aspergilose Invasiva conforme a European Organization for Research and Treatment of Cancer, a doença foi interpretada como comprovada em 7,3%, definida por cultura positiva para o fungo, 6,4% como provável pela detecção de galactomanana no sangue e presença de infiltrados pulmonares e 5,1% como possível por alterações radiológicas sugestivas de Aspergilose Invasiva e galactomanana negativo. A taxa de mortalidade para Aspergilose Invasiva comprovada/provável/possível foi de 61,3% e mostrou que a doença estava significativamente associada com o risco de morte (p<0,0001). Ao considerarmos a alta taxa de mortalidade causada pelo desenvolvimento da Aspergilose Invasiva e que a realização de uma terapia precoce promove significativa melhora do prognóstico dos pacientes, concluímos que a detecção de galactomanana, realizada como acompanhamento dos pacientes com alto risco de desenvolver a doença, pode ser considerada um método eficaz para auxiliar na identificação de Aspergilose Invasiva. O segundo artigo, intitulado “Associação entre polimorfismos dos genes que codificam os receptores celulares Dectina-1 e Toll-like e susceptibilidade à Aspergilose Invasiva”, teve como objetivo descrever os polimorfismos nos genes que codificam os receptores Dectina-1 e Toll-like, buscando possíveis associações com a susceptibilidade individual à Aspergilose Invasiva. Este estudo utilizou como base metodológica uma revisão sistemática da literatura e como base de dados a PubMed e PMC do NCBI. As palavras-chaves utilizadas foram: Invasive aspergillosis, polymorphism, Dectin-1 e Toll-like. A partir desta busca, 415 estudos foram encontrados e de acordo com os critérios de inclusão e exclusão 8 estudos foram selecionados. Com a realização deste, constatou-se que vários são os estudos que descrevem os polimorfismos de base única com uma maior susceptibilidade à Aspergilose Invasiva. Os principais são em genes que codificam os receptores Toll-like e os que codificam citocinas e quimiocinas (Dectina-1). Assim, pode-se perceber que de acordo com estudos já realizados há uma associação significativa de polimorfismos genéticos com a Aspergilose Invasiva, porém estudos mais amplos devem ser realizados para se obter resultados mais fidedignos. De modo geral, concluímos com essa dissertação que o desenvolvimento da Aspergilose Invasiva está associado com diversos fatores, sendo um deles o genético, e que, devido aos altos índices de mortalidade causados pela Aspergilose Invasiva, a detecção de galactomanana é de fundamental importância para o tratamento dos pacientes que apresentam uma maior probabilidade de desenvolver a doença, auxiliando principalmente no prognóstico e diagnóstico precoce da mesma.