Evaluation of cytokines produced by β-hemolytic streptococcus in acute pharyngotonsillitis / Avaliação das citosinas produzidas por estreptococos β-hemolíticos em faringotonsilites agudas

INTRODUCTION: The most common pathogen in bacterial pharyngotonsillitis is group A β-hemolytic streptococcus, although groups B, C, F,and G have also been associated with pharyngotonsillitis.OBJECTIVE: To assess the levels of the cytokines TNF-α, IL-6,IL-4, and IL-10 in bacterial pharyngotonsillitis caused by group A and non-A (groups B, C, F and G) β-hemolytic streptococcus.METHODS: The study was conducted at a pediatric emergency care unit. The sample comprised children (5-9 years old) with acute bacterial pharyngotonsillitis diagnosed between December of 2011 and May of 2012. The research involved collection of blood samples from the patients, enzyme-linked immunosorbent assay detection of TNF-α, IL-6,IL-4, and IL-10, and collection of two oropharyngeal swabs for bacterial isolation. Additionally, the medical history of the study participants was also collected.RESULTS: In the studied group (mean age: 5.93 years), higher pharyngotonsillitis incidence was observed in the female gender (64.76%). Higher incidence of tonsillar exudates was observed with groups A and C. No statistically significant differences in cytokine levels were observed among groups. However, the group A and the control group showed a difference in the IL-6 level (p = 0.0016).CONCLUSIONS: The Groups A and C showed higher cytokine levels than the Groups B and control, suggesting similar immunological patterns.

INTRODUÇÃO: O patógeno mais comumente associado à faringotonsilite bacteriana é o estreptococo β-hemolítico do grupo A, a despeito dos grupos B, C, F e G terem também sido associados com a faringotonsilite.OBJETIVO: Determinar os níveis das citosinas TNF-α, IL-6, IL-4, e IL-10 na faringotonsilite bacteriana causada pelos estreptococos β-hemolíticos do grupo A e não-A (grupos B, C, F e G).MÉTODO: O estudo foi conduzido em uma emergência pediátrica. A amostra estudada compreendeu crianças (entre 5 e 9 anos) com faringotonsilite aguda bacteriana diagnosticada entre dezembro de 2011 e maio de 2012. A pesquisa envolveu a coleta de amostras sanguíneas dos pacientes, a detecção, através do ELISA, de TNF-α, IL-6, IL-4, and IL-10, além da coleta de dois swabs orofaríngeos para isolamento bacteriano. Adicionalmente foi coletada a história médica dos participantes do estudo.RESULTADOS: No grupo estudado (idade média: 5,93 anos), a maior incidência de faringotonsilite foi observada no gênero feminino (64,76%). Foram detectadas maiores incidências de exsudatos tonsilares nos grupos A e C. Não foram observadas diferenças estatisticamente significantes dos níveis de citosinas entre os grupos. Porém os grupos A e o controle mostraram diferença nos níveis de IL-6 (p = 0.0016).CONCLUSÕES: Os grupos A e C mostraram maiores níveis de citosinas que os grupos B e o controle, sugerindo mecanismos imunológicos similares.

Distinct cytokine profiles of circulating mononuclear cells stimulated with Staphylococcus aureus enterotoxin A in vitro during early and late episodes of chronic osteomyelitis

We investigated the cytokine profile of peripheral mononuclear cells from chronic osteomyelitis (OST) patients following in vitro stimulation with staphylococcal enterotoxin A (SEA). We demonstrate that stimulation with SEA induced prominent lymphocyte proliferation and high levels of tumour necrosis factor (TNF)-α, interleukin (IL)-4 and IL-10 secretion in both OST and non-infected individuals (NI). Even though stimulation with SEA had no impact on IL-6 production in either patient group, the baseline level of IL-6 production by cells from OST patients was always significantly less than that produced by cells from NI. After classifying the osteomyelitic episodes based on the time after the last reactivation event as "early" (1-4 months) or "late" osteomyelitis (5-12 months), we found that increased levels of TNF-α and IL-4 in combination with decreased levels of IL-6 were observed in the early episodes. By contrast, increased levels of IL-10, IL-2 and IL-6 were hallmarks of late episodes. Our data demonstrate that early osteomyelitic episodes are accompanied by an increased frequency of "high producers" of TNF-α and IL-4, whereas late events are characterised by increased frequencies of "high producers" of IL-10, IL-6 and IL-2. These findings demonstrate the distinct cytokine profiles in chronic osteomyelitis, with a distinct regulation of IL-6 production during early and late episodes.

Protease-Activated Receptor 2 Is Involved in Th2 Responses against Trichinella spiralis Infection

In order to get a better understanding of the role of protease-activated receptor 2 (PAR2) in type 2 helper T (Th2) cell responses against Trichinella spiralis infection, we analyzed Th2 responses in T. spiralis-infected PAR2 knockout (KO) mice. The levels of the Th2 cell-secreted cytokines, IL-4, IL-5, and IL-13 were markedly reduced in the PAR2 KO mice as compared to the wild type mice following infection with T. spiralis. The serum levels of parasite-specific IgE increased significantly in the wild type mice as the result of T. spiralis infection, but this level was not significantly increased in PAR2 KO mice. The expression level of thymic stromal lymphopoietin, IL-25, and eotaxin gene (the genes were recently known as Th2 response initiators) of mouse intestinal epithelial cells were increased as the result of treatment with T. spiralis excretory-secretory proteins. However, the expression of these chemokine genes was inhibited by protease inhibitor treatments. In conclusion, PAR2 might involve in Th2 responses against T. spiralis infection.

Boosting the suppressive effects of Ascaris suum components in IFN-γ-deficient mice / Potencialização do efeito supressor de componentes do Ascaris suum em camundongos deficientes em IFN-γ

High molecular weight components from Ascaris suum extract suppress ovalbumin-specific immunity in mice. In IFN-γ-deficient mice, ovalbumin-specific delayed-type hypersensitivity reactions are more strongly downregulated by these suppressive components. Here, the cellularity of the delayed-type hypersensitivity reaction in IFN-γ-deficient mice and the increased downregulation induced by Ascaris suum components were analyzed. IL-12p40-dependent neutrophilic influx was predominant. Suboptimal doses of the suppressive fraction from this nematode completely inhibited the hypersensitivity reaction, thus indicating intensification of the immunosuppression under conditions of intense recruitment of IFN-γ-independent neutrophils.

Componentes de alto peso molecular do extrato de Ascaris suum suprimem a imunidade específica à ovalbumina em camundongos. Em camundongos geneticamente deficientes de IFN-γ a reação de hipersensibilidade tardia específica para ovalbumina foi mais fortemente prejudicada por estes componentes supressivos. Aqui, a celularidade da reação de hipersensibilidade tardia em camundongos deficientes de IFN-γ e o incremento na supressão induzida por componentes do Ascaris suum foram analisados. Influxo neutrofílico, dependente de IL-12p40, foi predominante. Dose sub-ótima da fração supressiva do nematódeo inibiu completamente a reação de hipersensibilidade, indicando uma intensificação da imunossupressão em condições de recrutamento intenso de neutrófilos independente de IFN-γ.

Immediate exposure to TNF-alpha activates Dendritic cells derived from non-purified cord blood mononuclear cells

Tumor necrosis factor alpha [TNF-alpha] is a primary mediator of immune regulation and might be required in the early stages of DC development from CD34[+] cells. However, details of optimal timing of exposure to TNF-alpha in DC development process in monocytes or non-purified hematopoitic cells are still lacking and clear benefits of this approach to the development of DCs remain to be validated. To evaluate the effect of early and late exposure to TNF-alpha on DC development from non-purified cord blood mononuclear cells. To define the effects of early exposure to TNF-alpha on cord blood mononuclear cells, we cultured UCB-MNC in the presence of SCF, Flt3L, GM-CSF and IL-4 for 14 days and matured them for an extra 4 days. TNF-alpha was added on day 0, 7 and 14 in TNF-alpha [+] group, and only on day 14 in TNF-alpha [-] group where it was used only as a maturation factor. Immediate exposure to TNF-alpha was shown to: [1] enhance the survival of cells in the first week of culture; [2] produce mature DCs with higher maturation markers [CD80, CD83, CD86 and HLA-DR]; and [3] increase secretion of IL-12 by mature DCs. In contrast, delayed exposure to TNF-alpha stimulate mature DCs with less purity producing a high level of IL-10 and a low level of IL-12. We developed a simple, easy and cost effective method to generate DCs from non-fractionating mononuclear cells in this study. Also we confirm the presence of a large number of functional DCs under inflammatory conditions, where local concentrations of TNF-alpha were high

An in vitro model for dengue virus infection that exhibits human monocyte infection, multiple cytokine production and dexamethasone immunomodulation

An important cytokine role in dengue fever pathogenesis has been described. These molecules can be associated with haemorrhagic manifestations, coagulation disorders, hypotension and shock, all symptoms implicated in vascular permeability and disease worsening conditions. Several immunological diseases have been treated by cytokine modulation and dexamethasone is utilized clinically to treat pathologies with inflammatory and autoimmune ethiologies. We established an in vitro model with human monocytes infected by dengue virus-2 for evaluating immunomodulatory and antiviral activities of potential pharmaceutical products. Flow cytometry analysis demonstrated significant dengue antigen detection in target cells two days after infection. TNF-alpha, IFN-alpha, IL-6 and IL-10 are produced by in vitro infected monocytes and are significantly detected in cell culture supernatants by multiplex microbead immunoassay. Dexamethasone action was tested for the first time for its modulation in dengue infection, presenting optimistic results in both decreasing cell infection rates and inhibiting TNF-alpha, IFN-alpha and IL-10 production. This model is proposed for novel drug trials yet to be applyed for dengue fever.

Effect of myocardial protection and perfusion temperature on production of cytokines and nitric oxide during cardiopulmonary bypass / Efeito da proteção miocárdica e temperatura de perfusão sobre a produção de citocinas e óxido nítrico durante bypass cardiopulmonar

PURPOSE: To investigate the effects of different conditions used during cardiopulmonary bypass (CPB) surgery on accompanying production of cytokine and nitric oxide (NO). METHODS: Patients undergoing CPB for the first time were prospectively enrolled and divided into two groups according to CPB parameters performed: i) normothermia (36.5-37°C) with blood cardioplegia (NB group, n=10) and ii) hypothermia (29-31°C) with crystalloid cardioplegia (HC group, n=10). Plasma samples obtained following intubation (baseline), during (5 and 30 min) and after (4 and 24 h) CPB were assayed for cytokines (ELISA) and NO metabolites (Griess reaction). RESULTS: Peak concentrations of interleukin (IL)-6 and IL-8 were reached at 4 h post CPB in both groups, but in the HC group those levels increased earlier and persisted for longer (24 h) compared to baseline (P < 0.05). IL-10 levels also increased at 4 h compared to baseline, but only significantly so in the HC group. NO metabolites were reduced in HC group at all time points compared to baseline (P < 0.05), while no significant differences were detected in the NB group. CONCLUSION: The association between increased systemic levels of cytokines and reduced NO production in the HC group suggests that different myocardial protection and/or perfusion temperature used during CPB may contribute to the extent of inflammatory response.

OBJETIVO: Investigar a hipótese de que diferentes procedimentos durante o bypass cardiopulmonary (BCP) causa diferentes níveis de citocinas (IL) e óxido nítrico (NO). MÉTODOS: Pacientes submetidas a BCP foram prospectivamente estudadas de acordo com bypass realizado sobre normotermia (36.5-37°C) com cardioplegia sanguínea (NB group, n=10) or hipotermia (29-31°C) com cardioplegia cristalóide (HC group, n=10). Amostras de Plasma foram obtidas após a intubação (linha de base), durante (5, 30 min) e após (4, 24 h) o BCP. Os ensaios foram realizados através de ELISA (IL) e metabólitos do NO (reação de Griess). RESULTADOS: Os picos de concentrações de IL-6 and IL-8 estavam aumentados em 4 h pós BCP em ambos os grupos, mas no grupo HC estes níveis aumentaram precocemente e persistiram aumentadas por 24 h, comparado a linha de base (P<0.05). O nível de IL-10 também teve o pico em 4 h, mas estatisticamente significante somente no grupo HC, comparado a linha de base. Os metabólitos do NO estavam reduzidos no grupo HC, em todo o tempo, comparado a linha de base (P<0.05), enquanto nenhuma diferença estatisticamente significante foi detectada no grupo NB. CONCLUSÃO: A associação entre o aumento sistêmico dos níveis de citocina e a redução da produção de NO no grupo HC sugere que o tipo de proteção miocárdica e/ou temperatura de perfusão no BCP pode ser um fator determinante na extensão da resposta inflamatória.

Calcineurin inhibitors in the treatment of allergic dermatitis

OBJETIVO: Revisar o papel dos inibidores da calcineurina no tratamento das dermatoses alérgicas, com ênfase nos mecanismos de ação, eficácia e efeitos adversos tópicos e sistêmicos. FONTES DOS DADOS: Artigos de língua inglesa publicados na MEDLINE, considerando as palavras chave: pimecrolimus, tacrolimo, calcineurin inhibitors. Foram selecionados os artigos originais que apresentaram estudos controlados e estudos abertos para avaliação da eficácia, tolerabilidade e eventos adversos. Também foram avaliados artigos de revisão e relatos e série de casos, sendo estes últimos considerados apenas para avaliação de efeitos adversos. Foram consultados os sites oficiais da Food and Drug Administration e dos fabricantes de inibidores da calcineurina. SíNTESE DOS DADOS: Os dados mostraram que inibidores de calcineurina são eficientes no tratamento da dermatite atópica leve a grave, levando a melhora dos sintomas, diminuição do número de crises e necessidade de corticoterapia tópica. Apresentam boa tolerabilidade e poucos efeitos adversos tópicos. Até o momento, não há evidências que sustentem a maior prevalência de neoplasias nos pacientes que utilizam esses medicamentos; entretanto, um adequado sistema de farmacovigilância está montado para avaliar esse aspecto. CONCLUSÕES: Os inibidores de calcineurina são uma nova classe de medicamentos para o tratamento das dermatoses alérgicas. São eficazes, tolerados e com poucos efeitos adversos. Devem ser sempre utilizados de acordo com as orientações preconizadas, e os pacientes devem ser sempre acompanhados pelo médico durante e após sua administração.

OBJECTIVE: To review the role of calcineurin inhibitors in the treatment of allergic dermatitis, focusing on mechanisms of action, efficacy and topical and systemic adverse effects. SOURCES: Articles written in English and published in MEDLINE using the following keywords: pimecrolimus, tacrolimus, calcineurin inhibitors. Original articles that presented controlled and open studies for assessing efficacy, tolerability and adverse effects were selected. Review articles and case series were also evaluated; the latter was only considered for assessing adverse effects. The official websites of the Food and Drug Administration and of manufacturers of calcineurin inhibitors were also used. SUMMARY OF THE FINDINGS: The data showed that calcineurin inhibitors are efficient in the treatment of mild to severe atopic dermatitis, leading to improvement in symptoms, reduction in number of attacks and need of topical corticotherapy. Calcineurin inhibitors have good tolerability and few topical adverse effects. To date, there has been no evidence to support higher prevalence of neoplasia in patients using these drugs; however, an adequate pharmacovigilance system has been set up to assess this aspect. CONCLUSIONS: Calcineurin inhibitors, which are a new drug class in the treatment of allergic dermatitis, are efficient, well tolerated and have few adverse effects. Calcineurin inhibitors should always be used according to recommended guidelines, and patients should always be followed by the physician during and after their administration.

Role of cytokines in immune response to pulmonary tuberculosis.

Immunopathogenesis of tuberculosis needs to be explored in search of a proper vaccine as well as for adjunctive immunotherapy particularly in patients with drug resistant tuberculosis. In tuberculosis, IFN-gamma, a product of T lymphocytes, contributes to protective immunity against M. tuberculosis by activating macrophages to a more effective elimination of these organisms. Interleukin-12 and interleukin-18 are macrophage products that favor the development of Th1 type of protective immune response. Production of these cytokines may not only facilitate granuloma formation and bacillary elimination but may also cause local tissue necrosis and systemic effects such as fever and wasting, due to the release of TNF-alpha into the circulation. The production of anti-inflammatory cytokines such as IL-10, TGF-beta and IL-4 in response to M. tuberculosis may down regulate the immune response and limit tissue injury by inhibiting excessive inflammatory response. These cytokines, if produced in excess, may result in failure to control infection resulting in widely disseminated tuberculosis. It is the balance between the inflammatory and protective immune response that determines the outcome of tuberculosis infection. In that context, increased IFN-y as against reduced TNF-alpha probably suggests a better outcome. Similarly, an effective vaccine has to stimulate a precise combination of T cells and cytokines needed for the many aspects of immune response and a potent immunotherapeutic agent may require to encompass the multiple parameters to be of therapeutic relevance.

Expression of extracellular matrix components and their receptors in the central nervous system during experimental Toxoplasma gondii and Trypanosoma cruzi infection

Alterations in extracellular matrix (ECM) expression in the central nervous system (CNS) usually associated with inflammatory lesions have been described in several pathological situations including neuroblastoma and demyelinating diseases. The participation of fibronectin (FN) and its receptor, the VLA-4 molecule, in the migration of inflammatory cells into the CNS has been proposed. In Trypanosoma cruzi infection encephalitis occurs during the acute phase, whereas in Toxoplasma infection encephalitis is a chronic persisting process. In immunocompromised individuals such as AIDS patients, T. cruzi or T. gondii infection can lead to severe CNS damage. At the moment, there are no data available regarding the molecules involved in the entrance of inflammatory cells into the CNS during parasitic encephalitis. Herein, we characterized the expression of the ECM components FN and laminin (LN) and their receptors in the CNS of T. gondii- and T. cruzi-infected mice. An increased expression of FN and LN was detected in the meninges, leptomeninges, choroid plexus and basal lamina of blood vessels. A fine FN network was observed involving T. gondii-free and T. gondii-containing inflammatory infiltrates. Moreover, perivascular spaces presenting a FN-containing filamentous network filled with Alpha 4+ and Alpha 5+ cells were observed. Although an increased expression of LN was detected in the basal lamina of blood vessels, the CNS inflammatory cells were alpha 6-negative. Taken together, our results suggest that FN and its receptors VLA-4 and VLA-5 might be involved in the entrance, migration and retention of inflammatory cells into the CNS during parasitic infections

Moléculas de cooperación y regulación durante la migración celular en la respuesta inflamatoria / Molecules for cooperation and regulation during cell migration in the inflammatory response

En la superficie de todas las células existen estructuras sacarídicas, dentro de sus múltiples funciones fisiológicas se ha logrado identificar que funcionan como comunicadores intercelulares. En el caso de los leucocitos estas estructuras le permiten, por mecanismos de adherencia, identificar a los sitios de inflamación, este proceso se efectúa gracias a la interacción específica de diversas familias de glicoproteínas de superficie celular entre las que se considera a las denominadas "selectinas", las integrinas y las moléculas pertenecientes a la superfamilia de las inmunoglobulinas. En este Trabajo, se revisan las características moleculares de estas proteínas adhesivas y, los diversos procesos inflamatorios en los que están involucradas