<p>Uvod: Interleukin 33 (IL-33) ima značajnu ulogu u inflamatornim i autoimunskim oboljenjima, ali se sve vi&scaron;e proučava njegov značaj u imunopatogenezi različitih alergijskih oboljenja, uključujući i alergijsku astmu (AA). Cilj: Ispitivanje vrednosti IL-33 u serumu pacijenata sa AA pre i posle &scaron;estomesečne inhalatorne kortikosteroidne terapije (ICS Th) i povezanosti dobijenih vrednosti IL-33 sa određenim kliničkim i laboratorijskim karakteristikama ovih pacijenata. Metode: Vrednost IL-33 u serumu određena je kod 61 pacijenta sa AA pre započinjanja i posle sprovedne &scaron;estomesečne ICS Th i kod 30 zdrave dece. U obradi podataka primenjene su standardne metode deskriptivne i analitičke statistike. Rezultati: Kod pacijenata sa nelečenom AA, serumske vrednosti IL-33 su signifikantno veće u odnosu na pacijente kod kojih je sprovedena &scaron;estomesečna ICS Th (p&lt;0,05), kao i u odnosu na zdravu decu (p&lt;0,01). Pacijenti sa AA koji su tokom 6 meseci lečeni sa ICS Th i zdrava deca imaju slične vrednosti IL-33 u serumu (p&gt;0,05). Kod pacijenata sa AA pre započinjanja i 6 meseci posle primene ICS Th ne postoji signifikantna korelacija između vrednosti IL-33 u serumu i eozinofilnih granulocita periferne krvi (p&gt;0,05), eozinofilnih granulocita u nazalnom sekretu (p&gt;0,05) i ukupnog IgE u serumu (p&gt;0,05). Kod pacijenata sa nelečenom AA postoji signifikantna negativna korelacija između vrednosti serumskog nivoa IL-33 i sledećih parametara plućne fukcije: FEV1 (p&lt;0,05), FEV1/FVC (p&lt;0,05), PEF(p&lt;0,05) i MEF 25/75 (p&lt;0,05). Posle &scaron;estomesečne ICS Th pobolj&scaron;ava se plućna funkcija, odnosno dolazi do porasta brzine protoka vazduha u disajnim putevima kao i promena u plućnim volumenima u zavisnosti od stepena opstrukcije u odnosu na vrednosti pre uključenja antiinflamatorne terapije (FEV1, FVC, FEV1/FVC, PEF, MEF 25/75, za sve vrednosti p&lt;0,01). Dok je signifikantna negativna korelacija dokazana između IL-33 i vrednosti FEV1 (p&lt;0,01), FVC (p&lt;0,01) i PEF (p&lt;0,05). Zaključak: Serumski nivo IL-33 je značajno povi&scaron;en kod dece sa nelečenom, odnosno nekontrolisanom AA. &Scaron;estomesečna primena ICS dovodi do značajne redukcije IL-33 u serumu čije su vrednosti u negativnoj korelaciji sa vrednostima FEV1, FVC i PEF, odnosno pozitivnoj korelaciji sa težinom i kontrolom AA. Rezultati na&scaron;e studije ističu da IL-33 ima značajnu ulogu u imunopatogenezi AA. Određivanje serumske vrednosti IL-33 može biti koristan indikator težine AA.</p> / <p>Introduction: Interleukin 33 (IL-33) plays a significant role in inflammatory and autoimmune diseases, but its significance in the immunopathogenesis of various allergic diseases including allergic asthma (AA) has gained increasing attention in research over recent years. Objective: Testing serum levels of IL-33 in patients with AA before and after a six-month inhaled corticosteroid therapy (ICS Th) and correlation of IL-33 values with specific clinical and laboratory characteristics of these patients. Methods: Serum levels of IL-33 were determined in 61 patients with AA prior to the initiation of ICS Th and following the six-month ICS Th as well as in 30 healthy children. Data processing was performed applying standard methods of descriptive and analytical statistics. Results: In patients with untreated AA, serum levels of IL-33 were significantly higher as compared to the patients who have received a six month ICS Th (p &lt;0.05) as well as to healthy children (p &lt;0.01). Patients with AA, who were treated with ICS Th for six months, and healthy children have similar serum IL-33 (p&gt; 0.05). In patients with AA, significant correlation between serum IL-33 levels and eosinophilic peripheral blood granulocytes (p&gt;0.05), eosinophilic granulocytes in nasal secretion (p&gt;0.05) and the total IgE in serum has not been observed for the period prior to initiation and 6 months after the administration of ICS Th. In patients with untreated AA, there is significant negative correlation between serum IL-33 and the following pulmonary functions test results: FEV1 (p&lt;0.05), FEV1/FVC (p&lt;0.05), PEF (p&lt;0.05) and MEF 25/75 (p&lt;0.05). After a six-month ICS Th, significant improvement of pulmonary functions was evident, that is, increase in airflow speed and lung volume change as compared to the values determined before the initiation of the anti-inflammatory therapy (FEV1, FVC, FEV1/FVC, PEF, MEF 25/75, for all values p&lt;0.01). Significant negative correlation between IL-33 and the values of FEV1 (p&lt;0.01), FVC (p&lt;0.01)and PEF (p&lt;0.05) has been established. Conclusion: Serum level of IL-33 is significantly elevated in children with untreated, i.e., uncontrolled AA. A six-month ICS Th asthma treatment results in significant reduction of serum levels of IL-33. This level is negatively correlated with FEV1, FVC and PEF values while positively correlated with the severity of the disease and control of AA. The results of our study point out that IL-33 plays an important role in the immunopathogenesis of AA. Quantification of serum IL-33 levels can be a useful indicator of the severity of AA.</p>

This study demonstrates original findings of statin effects on IL-33 stimulated mast cells. Statins are a class of drugs used to lower cholesterol production by targeting HMG CoA reductase. These commonly prescribed drugs have been shown to be immunomodulatory. In this study, we have found that pretreatment with statins has a variety of effects on IL-33 stimulated mast cells. Atorvastatin suppresses TNF and IL-6 production, while fluvastatin significantly enhances release of these proinflammatory cytokines in BMMCs. Although they have differing effects on cytokine production, both statins lowered ST2 expression on the cell surface, decreased cell viability, and enhanced expression of the transcription factor KLF2, a negative regulator of NFκB. Blocking isoprenylation by using geranylgeranyl transferase inhibitor, but not farnesyl transferase, mimicked the effects of atorvastatin, while neither mirrored the effect of fluvastatin. Furthermore, fluvastatin effects were not reversed by mevalonic acid, the product of HMG-CoA reductase. These data indicate that fluvastatin effects are distinct from its activities as an HMG CoA reductase inhibitor. Fluvastatin effects required the presence of stem cell factor (SCF), and were enhanced by increasing SCF concentrations. Finally, fluvastatin enhanced IL-33-induced cytokine production and neutrophil recruitment in vivo. Collectively, these data suggest that statins can alter the mast cell response, and that drug choice can have divergent effects on outcome.

IL-33 is a pleiotropic cytokine that orchestrates both innate and adaptive immunity. It is commonly associated with type 2 immune responses but recently expression of the IL-33 receptor, ST2, was reported on Treg cells found preferentially in non-lymphoid tissues, such as the visceral adipose tissue, muscle or colon. A crucial role of Tregs in maintaining intestinal homeostasis has been well described. However, little is known about the functional relevance of the ST2-expressing Treg population in the colon. Phenotypic and functional characterisation of Tregs in the gut revealed the presence of two distinct populations: ST2⁺/Gata3⁺ and Ror&gamma;t⁺ Tregs. Thymic-derived ST2⁺/Gata3⁺ Tregs showed a more activated phenotype and produced IL-10 under homeostatic conditions. Upon microbial challenge and colitis, ST2+/Gata3+ Tregs were decreased, while Ror&gamma;t⁺ Tregs expanded. Furthermore, in vitro experiments demonstrated that IL-33 directly induced activation of the Gata3 pathway in Tregs, which enhanced expression of Foxp3 and ST2. Additionally, amphiregulin was also induced in Tregs upon stimulation with IL-33. However, in vivo, IL-33 was dispensable for both the maintenance of Treg cells under homeostatic conditions and Treg function in Helicobacter hepaticus-driven colitis. Investigation of the negative regulators of IL-33 showed that IL-23 inhibited IL-33-mediated effects on Tregs. We also observed increased production of soluble ST2 by stromal cells during intestinal inflammation, which likely contributed to the reduction of IL-33 bioavailability. Finally, a systematic analysis of the cellular source of IL-33 revealed that PDGRF&alpha;⁺ stromal cells located in the T cell zone of secondary and tertiary lymphoid tissues were a major IL-33-producing cell population in the gut. Collectively, our findings suggest that signals received by the stromal compartment upon cell injury may trigger a specific phenotype of Tregs with a repair capacity, and thus, promote intestinal homeostasis. These findings improve our understanding of tissue-resident Tregs and open an exciting avenue to explore heterocellular signalling between stromal cells and Tregs.

No / Interleukin-33 has recently gained much attention due to its role in allergic responses. It has been shown to amplify Th2 responses and to act as a damage-associated molecular pattern. IL-33 acts on a broad range of cells and has been proposed to link innate and adaptive features of allergic responses. It was the aim of this study to investigate this property of IL-33 in the inflammatory response characterising atopic dermatitis (AD). We have analysed the response of skin-resident cells derived from patients with AD and healthy donors with regard to the expression of IL-33 and its receptor ST2. The functional impact of IL-33 on CD4+ T cells was investigated. Keratinocytes and dermal fibroblasts clearly differ in their regulation of IL-33. In fibroblasts, the concerted action of TNF-α and IL-1β was the strongest inducer, whereas IFN-γ is clearly the key molecule that upregulates IL-33 in keratinocytes with a more pronounced response of cells derived from patients with AD. Keratinocytes from patients with AD showed a markedly higher constitutive expression level of surface ST2. CD4+ T cells respond to IL-33. Unexpectedly, IL-33 failed to induce a significant secretion of IL-5 or IL-13. By contrast, high amounts of IFN-γ were detectable if IL-33 was added to the T-cell receptor-stimulated cells or in combination with IL-12. These results suggest that IL-33 and IFN-γ are closely interlinked in epidermal AD inflammation. IFN-γ induces IL-33 in keratinocytes and IL-33 acts on activated T cells to further increase the release of IFN-γ, therefore contributing to drive skin inflammation towards chronic responses.

L’asthme est une maladie inflammatoire chronique des voies aériennes. Chez les individus sensibles, l’inhalation d’allergènes entraine une inflammation pulmonaire se traduisant par des épisodes récurrents de toux, de difficultés respiratoires et une sécrétion de mucus. Des études réalisées chez l’animal ont mis en évidence un rôle crucial des lymphocytes Th2 et des cytokines associées (IL-4, IL-5 et IL-13). Plus récemment, il a été montré que les lymphocytes Th17 participaient à la physiopathologie de l’asthme. La présente étude s’intéresse à une cytokine majoritairement produite par les Th17 : l’IL-22. Différents travaux indiquent que cette cytokine serait impliquée dans l’immunitémucosale où elle exercerait des effets protecteurs ou pro-inflammatoires en fonction du modèle expérimental étudié. En utilisant un modèle murin d’inflammation pulmonaire allergique induite par l’ovalbumine, nous avons montré que l’IL-22 jouait un rôle pro-inflammatoire au cours de l’induction de l’asthme allergique puisque les souris déficientes en IL-22 développent une forme atténuée de la maladie. A l’inverse, nous avons constaté que l’IL-22 avait un effet protecteur dans la phase effectrice, et que cet effet était dépendant de l’IL-17A. Nos travaux mettent donc en lumière une double fonction de l’IL-22 dans l’asthme allergique chez la souris. En parallèle de ce travail, nous nous sommes intéressés au rôle de l’IL-1 et de l’inflammasome NLRP3 dans ce même modèle d’inflammation pulmonaire. Enfin, une troisième étude a permis de mettre en lumière un rôle encore inconnu de l’interleukine-33 dans l’activation des cellules dendritiques au cours de la mise en place de la réponse asthmatique. / Asthma is a heterogenous inflammatory disorder of the airways characterized by chronic airway inflammation, airway hyper-reactivity and by symptoms of recurrent wheezing, coughing and shortness breath. Understanding of the role of allergy and Th2 cells in asthma has benefited from mouse model of allergic asthma. Recently, several studies highlighted Th17 involvement in asthma pathogenesis. In the present study, we investigate the role of IL-22, a Th17-related cytokine, in a mouse model of allergic lung inflammation induced by ovalbumin. First, using IL-22 deficient mice, we demonstrated a pro-inflammatory role of IL-22 during the sensitization phase. In contrast, we observed a protective function of IL-22 during the effective phase. This protective effect of IL-22 seems to be dependent of IL-17. In conclusion, we demonstrate here a dual role of IL-22 in asthma pathogenesis. Since interleukin-1_ is critical for Th17 polarization in human, we also investigated the role of IL-1 signalling and NLRP3 inflammasome in our model of allergic airway inflammation. We showed that NLRP3 inflammasome and IL-1R/IL-1 pathway are critical to induce allergic lung inflammation, even in the absence of adjuvant. Finally, we studied the effect of interleukin-33 on dendritic cells activation and Th2 priming during antigen sensitization and in established asthma.

IL-33 participa em diversas doenças com funções pró-inflamatórias e protetoras, de acordo com o contexto do microambiente. Com relação a biologia tumoral, o papel de IL-33 ainda é controverso. Estudos demonstraram que IL-33 possui efeitos pró e anti-inflamatórios em diferentes modelos animais de câncer. A presença desta citocina no estroma favorece a imunossupressão pela ativação de células T reguladoras e células mieloides supressoras. IL- 33 pode em outras situações promover a imunogenicidade e a resposta imune antitumoral de tipo 1 através das células T citotóxicas e células Natural Killers. Contudo o efeito preciso de IL-33 em diferentes tipos de câncer permanece incerto. Sendo assim, compreender o papel de IL-33 na imunobiologia do câncer, poderia direcionar esta citocina como um possível alvo em imunoterapias contra o câncer. Considerando, portanto, a pluralidade desta citocina no desenvolvimento de uma resposta imune, no presente estudo buscamos avaliar os efeitos do tratamento com anti-IL-33 em modelo experimental de carcinoma espinocelular de pele em camundongos BALB/c de linhagem selvagem. Ao final dos protocolos de indução e tratamento, a análise histopatológica revelou que o tratamento com anti-IL-33 levou a menor incidência de carcinoma espinocelular in situ e diminuição das atipias celulares e, consequentemente, do grau de displasia. O tratamento com anti-IL-33 levou a aumento nos percentuais de células B e diminuição nas percentagens de linfócitos T CD4+, células dendríticas, células TREG e macrófagos isolados do microambiente tumoral. Ademais, o tratamento com anti-IL-33 levou a aumento na percentagem de linfócitos T CD4+ produtores de IFN- e menor percentagem de linfócitos T CD4+ e CD8+ produtores de IL-4 nos linfonodos. Em camundongos submetidos ao tratamento, observou-se menor produção de TGF- no microambiente tumoral, sem interferir de modo significativo com a produção de IFN-, IL-4, IL-10 e IL-17. Os nossos resultados indicam que o tratamento com anti-IL-33 poderia ser alvo de novos estudos em busca de estratégias terapêuticas para o carcinoma espinocelular de pele. / IL-33 participates in several diseases with pro-inflammatory and protective functions, according to the context of the microenvironment. Related to tumor biology, the role of IL-33 is still controversial. Studies have shown that IL-33 has pro and anti-inflammatory effects in different animal models of cancer. Its presence in the stromal and tumor serum increases the immunosuppression by the activation of regulatory T cells and myeloid-derived suppressor cells. On the other hand, the intracellular form in tumor cells promotes immunogenicity and the antitumor type 1 immune response through cytotoxic T cells and natural killer cells. However, the precise effect of IL-33 on cancer conditions remains uncertain. Thus, understanding its role in the immunobiology of cancer could target this cytokine as a marker in cancer immunotherapies. Considering, the range of IL-33 in the development of an immune response, this study aims to evaluate the effects of the anti-IL-33 treatment on wild type BALB/c mouse squamous cell carcinoma (SSCC) development. Histopathological analysis revealed that anti-IL-33 treatment decreased the dysplasia. In addition, anti-IL-33 treatment showed an increasing percentage of B cells and reduced the percentage of CD4+ T lymphocytes, dendritic cells, TREG cells and macrophages in the tumor microenvironment. In the lymph node, anti-IL-33 treatment induced a shift towards the TH1 type cytokine profile and reduced the percentage of IL-4 expressing CD4+ and CD8+ cells. Additionally, anti-IL-33 treatment showed a reduced TGF- production in the tumor microenvironment, but with no changes to the IFN-, IL-4, IL-10 e IL-17 production. Taken together these results indicate that anti-IL-33 treatment could be the subject of further studies of therapeutic strategies for squamous cell carcinoma of the skin.

Contexto: Os mecanismos inflamatórios que determinam a gravidade da bronquiolite viral aguda em criançasainda não estão bem estabelecidos e parecem relacionados à disfunção da resposta imune. Objetivos: Avaliar a associação da interleucina-33 e do receptor ST2 com a gravidade da bronquiolite viral aguda. Métodos: Concentrações de IL-33, ST2, IL- 1ß, TNF?, IL-4, IL-6 e IL-8 foram avaliadas em secreção nasofaríngea e plasma de pacientes com bronquiolite viral aguda em dois momentos da internação hospitalar. A necessidade de ventilação mecânica constituiu o critério de gravidade da doença. Resultados: De janeiro de 2015 a dezembro de 2016, 261 crianças foram internadas com diagnóstico de bronquiolite viral aguda. Setenta e nove crianças foram incluídas no estudo; 33 (41,7%) foram submetidas à ventilação mecânica. Cento e oitenta e dois pacientes (69,7%) foram excluídos pelos seguintes motivos: uso de corticoide > 24h (n=156), múltiplas comorbidades (n=7), falha de recrutamento (n=11) e recusa dos responsáveis (n=8). Não houve associações entre etiologias virais ou presença de coinfecções e gravidade da doença. Verificaram-se detecções mais frequentes da IL-33 em secreção nasofaríngea à admissão hospitalar de pacientes submetidos à ventilação mecânica comparados com aqueles que não necessitaram de ventilação mecânica (50% vs. 13,3%, respectivamente; p<0,001). Observou-se o mesmo para o ST2 (87,5% no grupo submetido à ventilação vs. 40,9% no grupo não submetido à ventilação; p< 0,001). Na análise do quinto dia de internação entre os dois grupos, verificaram-se valores mais elevados em secreção nasofaríngea da IL-6 (mediana 152,6 pcg/ml no grupo submetido à ventilação vs. mediana 14,4 pcg/ml no grupo não submetido à ventilação; p=0,001) e IL-8 (mediana 1113 pcg/ml no grupo submetido à ventilação e mediana 792,2 pcg/ml no grupo não submetido à ventilação; p=0,03). Na comparação em secreção nasofaríngea entre os dois períodos de coleta, pacientes que necessitaram ventilação mecânica apresentaram redução das concentrações de ST2 (mediana 5,63 pcg/ml à admissão e mediana 2,44 pcg/ml no quinto dia de internação hospitalar; p=0,03) e aumento das concentrações de IL-4 (mediana 0,2 pcg/ml à admissão e mediana 6,9 pcg/ml no quinto dia; p<0,01) e IL-8 (mediana 342,9 pcg/ml à admissão e mediana 1.113 pcg/ml no quinto dia; p<0,01). Na análise entre os dois momentos de coleta no grupo não submetido à ventilação, demonstraram-se incrementos das concentrações em secreção nasofaríngea da IL-4 (mediana 0,2 pcg/ml à admissão e mediana 5,3 pcg/ml no quinto dia; p<0,01) e IL-8 (mediana 300,2 pcg/ml à admissão e mediana 792,2 pcg/ml no quinto dia; p<0,01), acompanhados de redução da IL-6 (mediana 86,0 pcg/ml à admissão e mediana 14,4 pcg/ml no quinto dia; p=0,04) e de incremento nas concentrações séricas da IL-33 (mediana 0,186,0 pcg/ml à admissão e mediana 36,2 pcg/ml no quinto dia; p=0,04). Conclusão: Detecções mais frequentes da IL-33 e do receptor ST2 durante a admissão hospitalar e concentrações elevadas de IL-6 e IL-8 em secreção nasofaríngea durante o quinto dia da internação foram associadas à gravidade da bronquiolite viral aguda. Não houve associação entre as etiologias virais ou a presença de coinfecções e a gravidade da doença. / Background: The inflammatory mechanisms influencing the severity of acute viral bronchiolitis in children are still not well established and seem to be caused by an immune dysfunction. Objectives: To assess if interleukin-33 and its receptor, ST2, can be used as clinical severity biomarkers in acute viral bronchiolitis. Methods: Levels of IL-33, ST2, IL-1ß, TNF?, IL-4, IL-6 e IL-8 were analyzed in nasopharyngeal aspirates and blood plasma of patients in two different moments after hospital admission. Severity of disease was defined by the presence of mechanical ventilation. Results: From January 2015 to December 2016, 261 were admitted due to acute viral bronchiolitis. Of the 79 children included in the study, 33 (41,7%) were submitted to mechanical ventilation. One hundred and eighty-two patients (69,7%) were excluded, due to use of corticosteroids (n=156), pre-existing comorbidities (n=7), recruitment failure (n=11) and parents refusal (n=8). No associations between viral etiology or the presence of coinfecctions and severity of disease were observed. IL-33 was more frequently detected in nasopharyngeal aspirates of patients submitted to mechanical ventilation during hospital admission (50% of samples of the mechanically ventilated group vs. 13,3% of the samples of children with no need of ventilator support; p<0,001). The same correlation was observed in ST2 levels (87,5% in the mechanically ventilated group vs. 40,9% of samples of children with no need of ventilator support; p< 0,001). On day five postadmission, an increase in concentrarions of nasopharyngeal aspirates in the mechanically ventilated patients was detected for IL-6 (median 152,6 pcg/ml in the mechanically ventilated group and median 14,4 pcg/ml for the group with no need of ventilator support; p=0,001) and IL-8 (median 1.113 pcg/ml in the mechanically ventilated group and median 792,2 pcg/ml for the group with no need of ventilator support; p=0,03). Between admission and day 5, increases of IL-4 (median 0,2 pcg/ml on admission and median 6,9 pcg/ml on day 5; p<0,01) and IL-8 (median 342,9 pcg/ml on admission and median 1.113 pcg/ml on day 5; p<0,01) levels were detected in nasopharyngeal aspirates, whereas ST2 levels showed a decrease (median 5,63 pcg/ml on admission and median 2,44 pcg/ml on day 5; p=0,03). In the same analysis performed in nasopharyngeal aspirates of patients with no need of ventilation support, an increase in IL-4 (median 0,2 pcg/ml on admission and median 5,3 pcg/ml on day 5; p<0,01) and IL-8 (median 300,2 pcg/ml on admission and median 792,2 pcg/ml on day 5; p<0,01) levels was observed and a decrease in IL-6 levels (median 86,0 pcg/ml on admission and median 14,4 pcg/ml on day 5; p=0,04), along with an increase in IL-33 blood plasma levels (median 0,186 pcg/ml on admission and median 36,2 pcg/ml on day 5; p=0,04) were also shown. Conclusion: More frequent detections of IL-33 and ST2 on the day of admission and higher IL-6 and IL-8 levels in nasopharyngeal aspirates were associated with more severe forms of acute viral bronchiolitis. No correlations between viral etiologies or the presence of coinfecctions and severity of disease were observed.

A citocina IL-33 apresenta papel dual e está envolvida com a resolução ou progressão de inúmeras doenças, além disso, acredita-se que a via IL-33/ST2 esteja envolvida no equilíbrio entre a atividade de osteoclastos e osteoblastos. O objetivo deste estudo foi avaliar o papel do receptor ST2 no desenvolvimento e progressão de lesões periapicais experimentalmente induzidas em camundongos. Lesões periapicais foram induzidas em primeiros molares inferiores de camundongos WT e ST2 knockout (KO). Decorridos 7 e 14 dias, as amostras de mandíbula foram submetidas às análises: determinação da área de lesão periapical em cortes histológicos e do volume por microtomografia computadorizada (&mu;CT); contagem de osteoclastos submetidos ao ensaio de histoenzimologia (TRAP); expressão gênica de marcadores osteogênicos e osteoclastogênicos por q-PCR; quantificação de neutrófilos por ensaio de mieloperoxidases. Os linfonodos foram submetidos à análise da expressão dos fatores transcricionais T-bet, GATA-3, RORc e Foxp-3 por q-PCR. Análise estatística utilizada foi One-way ANOVA, seguido de pós-teste de Bonferroni. Aos 14 dias, observou-se maior extensão da lesão periapical em animais WT que em ST2KO (p<0,05). O tamanho da lesão nos animais ST2KO permaneceu igual em função do tempo. Foi observada maior quantidade de neutrófilos na lesão do grupo WT aos 7 dias, em comparação aos animais ST2KO (p<0,05). Na expressão de T-bet, GATA-3, RORc e Foxp-3 não foram observadas diferenças estatisticamente significantes. O número de osteoclastos contados nos animais ST2KO foi maior que o observado em WT aos 7dias e aos 14 dias (p<0,05). A expressão de Runx2 foi maior no grupo lesão dos animais ST2KO quando comparado a seu respectivo controle. Os outros marcadores relacionados com a formação óssea não apresentaram diferenças estatisticamente significantes. Dentre os marcadores relacionados com a reabsorção óssea, a catepsina K e o MMP-9 apresentaram maior expressão aos 14 dias, na lesão dos animais WT quando comparada à expressão na lesão dos animais ST2KO (p<0,05). Com base nos resultados obtidos no presente estudo, pode-se concluir que na ausência do receptor ST2 as lesões periapicais são menos extensas e embora em maior quantidade, os osteoclastos são menos ativos. Nossos resultados sugerem um importante papel da via IL-33/ST2 na ativação dos osteoclastos e desenvolvimento da lesão periapical. / The IL -33 cytokine presents a dual role and is involved either in the resolution and progression of many diseases. Furthermore, it is believed that this pathway is involved between osteoclast and osteoblast activity balance. The aim of this study was to evaluate the role of ST2 receptor in the development and progression of experimentally induced periapical lesions in mice. Periapical lesions were induced in first molars of WT and ST2 knockout (KO) mice. After 7 and 14 days, jaw samples were subjected to various analysis: determination of periapical lesions area by histology and volume by computed microtomography (&mu;CT); osteoclasts number by TRAP histoenzymology; osteogenic and osteoclastogenic markers expression by q-PCR; neutrophil quantification by myeloperoxidase activity. The expression of transcription factors T-bet, GATA-3, RORC and Foxp-3 in lymph nodes were analysed by q-PCR. Statistical analysis was done by One-way ANOVA and Bonferroni post-test. It was observed a greater extent in periapical lesions of WT compared to ST2KO animals at 14 days (p<0.05). There is no progression in the lesion of ST2KO mice with the time. A larger number of neutrophils in WT group was observed, compared to ST2KO mice evaluated at 7 days (p<0.05). The expression of T-bet, GATA-3, RORc and Foxp-3 were not statistically significant different among the groups. The number of osteoclasts in lesions of ST2KO animals were greater than the observed in WT, at 7 and 14 days (p<0.05). Although, other osteogenic markers showed no statistically significant difference, Runx2 expression in ST2KO was higher in lesion side compared to control side at 14 days. The markers related to bone resorption, cathepsin K and MMP-9, were significantly abrogated in the lesion side of ST2KO mice, at 14 days (p<0.05). Based on the results, it can be concluded that although larger amounts of osteoclast were counted in ST2KO, the lesion was less extensive and osteoclasts less active. It all suggests that the IL-33/ST2 pathway play an important role in osteoclasts activation and periapical lesion development.

A citocina IL-33 apresenta papel dual e está envolvida com a resolução ou progressão de inúmeras doenças, além disso, acredita-se que a via IL-33/ST2 esteja envolvida no equilíbrio entre a atividade de osteoclastos e osteoblastos. O objetivo deste estudo foi avaliar o papel do receptor ST2 no desenvolvimento e progressão de lesões periapicais experimentalmente induzidas em camundongos. Lesões periapicais foram induzidas em primeiros molares inferiores de camundongos WT e ST2 knockout (KO). Decorridos 7 e 14 dias, as amostras de mandíbula foram submetidas às análises: determinação da área de lesão periapical em cortes histológicos e do volume por microtomografia computadorizada (&mu;CT); contagem de osteoclastos submetidos ao ensaio de histoenzimologia (TRAP); expressão gênica de marcadores osteogênicos e osteoclastogênicos por q-PCR; quantificação de neutrófilos por ensaio de mieloperoxidases. Os linfonodos foram submetidos à análise da expressão dos fatores transcricionais T-bet, GATA-3, RORc e Foxp-3 por q-PCR. Análise estatística utilizada foi One-way ANOVA, seguido de pós-teste de Bonferroni. Aos 14 dias, observou-se maior extensão da lesão periapical em animais WT que em ST2KO (p<0,05). O tamanho da lesão nos animais ST2KO permaneceu igual em função do tempo. Foi observada maior quantidade de neutrófilos na lesão do grupo WT aos 7 dias, em comparação aos animais ST2KO (p<0,05). Na expressão de T-bet, GATA-3, RORc e Foxp-3 não foram observadas diferenças estatisticamente significantes. O número de osteoclastos contados nos animais ST2KO foi maior que o observado em WT aos 7dias e aos 14 dias (p<0,05). A expressão de Runx2 foi maior no grupo lesão dos animais ST2KO quando comparado a seu respectivo controle. Os outros marcadores relacionados com a formação óssea não apresentaram diferenças estatisticamente significantes. Dentre os marcadores relacionados com a reabsorção óssea, a catepsina K e o MMP-9 apresentaram maior expressão aos 14 dias, na lesão dos animais WT quando comparada à expressão na lesão dos animais ST2KO (p<0,05). Com base nos resultados obtidos no presente estudo, pode-se concluir que na ausência do receptor ST2 as lesões periapicais são menos extensas e embora em maior quantidade, os osteoclastos são menos ativos. Nossos resultados sugerem um importante papel da via IL-33/ST2 na ativação dos osteoclastos e desenvolvimento da lesão periapical. / The IL -33 cytokine presents a dual role and is involved either in the resolution and progression of many diseases. Furthermore, it is believed that this pathway is involved between osteoclast and osteoblast activity balance. The aim of this study was to evaluate the role of ST2 receptor in the development and progression of experimentally induced periapical lesions in mice. Periapical lesions were induced in first molars of WT and ST2 knockout (KO) mice. After 7 and 14 days, jaw samples were subjected to various analysis: determination of periapical lesions area by histology and volume by computed microtomography (&mu;CT); osteoclasts number by TRAP histoenzymology; osteogenic and osteoclastogenic markers expression by q-PCR; neutrophil quantification by myeloperoxidase activity. The expression of transcription factors T-bet, GATA-3, RORC and Foxp-3 in lymph nodes were analysed by q-PCR. Statistical analysis was done by One-way ANOVA and Bonferroni post-test. It was observed a greater extent in periapical lesions of WT compared to ST2KO animals at 14 days (p<0.05). There is no progression in the lesion of ST2KO mice with the time. A larger number of neutrophils in WT group was observed, compared to ST2KO mice evaluated at 7 days (p<0.05). The expression of T-bet, GATA-3, RORc and Foxp-3 were not statistically significant different among the groups. The number of osteoclasts in lesions of ST2KO animals were greater than the observed in WT, at 7 and 14 days (p<0.05). Although, other osteogenic markers showed no statistically significant difference, Runx2 expression in ST2KO was higher in lesion side compared to control side at 14 days. The markers related to bone resorption, cathepsin K and MMP-9, were significantly abrogated in the lesion side of ST2KO mice, at 14 days (p<0.05). Based on the results, it can be concluded that although larger amounts of osteoclast were counted in ST2KO, the lesion was less extensive and osteoclasts less active. It all suggests that the IL-33/ST2 pathway play an important role in osteoclasts activation and periapical lesion development.

Contexto: Os mecanismos inflamatórios que determinam a gravidade da bronquiolite viral aguda em criançasainda não estão bem estabelecidos e parecem relacionados à disfunção da resposta imune. Objetivos: Avaliar a associação da interleucina-33 e do receptor ST2 com a gravidade da bronquiolite viral aguda. Métodos: Concentrações de IL-33, ST2, IL- 1ß, TNF?, IL-4, IL-6 e IL-8 foram avaliadas em secreção nasofaríngea e plasma de pacientes com bronquiolite viral aguda em dois momentos da internação hospitalar. A necessidade de ventilação mecânica constituiu o critério de gravidade da doença. Resultados: De janeiro de 2015 a dezembro de 2016, 261 crianças foram internadas com diagnóstico de bronquiolite viral aguda. Setenta e nove crianças foram incluídas no estudo; 33 (41,7%) foram submetidas à ventilação mecânica. Cento e oitenta e dois pacientes (69,7%) foram excluídos pelos seguintes motivos: uso de corticoide > 24h (n=156), múltiplas comorbidades (n=7), falha de recrutamento (n=11) e recusa dos responsáveis (n=8). Não houve associações entre etiologias virais ou presença de coinfecções e gravidade da doença. Verificaram-se detecções mais frequentes da IL-33 em secreção nasofaríngea à admissão hospitalar de pacientes submetidos à ventilação mecânica comparados com aqueles que não necessitaram de ventilação mecânica (50% vs. 13,3%, respectivamente; p<0,001). Observou-se o mesmo para o ST2 (87,5% no grupo submetido à ventilação vs. 40,9% no grupo não submetido à ventilação; p< 0,001). Na análise do quinto dia de internação entre os dois grupos, verificaram-se valores mais elevados em secreção nasofaríngea da IL-6 (mediana 152,6 pcg/ml no grupo submetido à ventilação vs. mediana 14,4 pcg/ml no grupo não submetido à ventilação; p=0,001) e IL-8 (mediana 1113 pcg/ml no grupo submetido à ventilação e mediana 792,2 pcg/ml no grupo não submetido à ventilação; p=0,03). Na comparação em secreção nasofaríngea entre os dois períodos de coleta, pacientes que necessitaram ventilação mecânica apresentaram redução das concentrações de ST2 (mediana 5,63 pcg/ml à admissão e mediana 2,44 pcg/ml no quinto dia de internação hospitalar; p=0,03) e aumento das concentrações de IL-4 (mediana 0,2 pcg/ml à admissão e mediana 6,9 pcg/ml no quinto dia; p<0,01) e IL-8 (mediana 342,9 pcg/ml à admissão e mediana 1.113 pcg/ml no quinto dia; p<0,01). Na análise entre os dois momentos de coleta no grupo não submetido à ventilação, demonstraram-se incrementos das concentrações em secreção nasofaríngea da IL-4 (mediana 0,2 pcg/ml à admissão e mediana 5,3 pcg/ml no quinto dia; p<0,01) e IL-8 (mediana 300,2 pcg/ml à admissão e mediana 792,2 pcg/ml no quinto dia; p<0,01), acompanhados de redução da IL-6 (mediana 86,0 pcg/ml à admissão e mediana 14,4 pcg/ml no quinto dia; p=0,04) e de incremento nas concentrações séricas da IL-33 (mediana 0,186,0 pcg/ml à admissão e mediana 36,2 pcg/ml no quinto dia; p=0,04). Conclusão: Detecções mais frequentes da IL-33 e do receptor ST2 durante a admissão hospitalar e concentrações elevadas de IL-6 e IL-8 em secreção nasofaríngea durante o quinto dia da internação foram associadas à gravidade da bronquiolite viral aguda. Não houve associação entre as etiologias virais ou a presença de coinfecções e a gravidade da doença. / Background: The inflammatory mechanisms influencing the severity of acute viral bronchiolitis in children are still not well established and seem to be caused by an immune dysfunction. Objectives: To assess if interleukin-33 and its receptor, ST2, can be used as clinical severity biomarkers in acute viral bronchiolitis. Methods: Levels of IL-33, ST2, IL-1ß, TNF?, IL-4, IL-6 e IL-8 were analyzed in nasopharyngeal aspirates and blood plasma of patients in two different moments after hospital admission. Severity of disease was defined by the presence of mechanical ventilation. Results: From January 2015 to December 2016, 261 were admitted due to acute viral bronchiolitis. Of the 79 children included in the study, 33 (41,7%) were submitted to mechanical ventilation. One hundred and eighty-two patients (69,7%) were excluded, due to use of corticosteroids (n=156), pre-existing comorbidities (n=7), recruitment failure (n=11) and parents refusal (n=8). No associations between viral etiology or the presence of coinfecctions and severity of disease were observed. IL-33 was more frequently detected in nasopharyngeal aspirates of patients submitted to mechanical ventilation during hospital admission (50% of samples of the mechanically ventilated group vs. 13,3% of the samples of children with no need of ventilator support; p<0,001). The same correlation was observed in ST2 levels (87,5% in the mechanically ventilated group vs. 40,9% of samples of children with no need of ventilator support; p< 0,001). On day five postadmission, an increase in concentrarions of nasopharyngeal aspirates in the mechanically ventilated patients was detected for IL-6 (median 152,6 pcg/ml in the mechanically ventilated group and median 14,4 pcg/ml for the group with no need of ventilator support; p=0,001) and IL-8 (median 1.113 pcg/ml in the mechanically ventilated group and median 792,2 pcg/ml for the group with no need of ventilator support; p=0,03). Between admission and day 5, increases of IL-4 (median 0,2 pcg/ml on admission and median 6,9 pcg/ml on day 5; p<0,01) and IL-8 (median 342,9 pcg/ml on admission and median 1.113 pcg/ml on day 5; p<0,01) levels were detected in nasopharyngeal aspirates, whereas ST2 levels showed a decrease (median 5,63 pcg/ml on admission and median 2,44 pcg/ml on day 5; p=0,03). In the same analysis performed in nasopharyngeal aspirates of patients with no need of ventilation support, an increase in IL-4 (median 0,2 pcg/ml on admission and median 5,3 pcg/ml on day 5; p<0,01) and IL-8 (median 300,2 pcg/ml on admission and median 792,2 pcg/ml on day 5; p<0,01) levels was observed and a decrease in IL-6 levels (median 86,0 pcg/ml on admission and median 14,4 pcg/ml on day 5; p=0,04), along with an increase in IL-33 blood plasma levels (median 0,186 pcg/ml on admission and median 36,2 pcg/ml on day 5; p=0,04) were also shown. Conclusion: More frequent detections of IL-33 and ST2 on the day of admission and higher IL-6 and IL-8 levels in nasopharyngeal aspirates were associated with more severe forms of acute viral bronchiolitis. No correlations between viral etiologies or the presence of coinfecctions and severity of disease were observed.