Association between interleukin-10 polymorphisms and CD4+CD25+FOXP3+ T cells in asthmatic children

Abstract Objective: The aim of this study was to evaluate the association between possible functional interleukin-10 (IL-10) polymorphisms, IL-10 expression and regulatory T cells (Tregs) frequency, and/or asthma severity in a sample of children and adolescents. Methods: This is a nested case-control genetic association study. The study sample consisted of children and adolescents aged 8-14 from public schools. Four polymorphisms of the IL-10 gene (rs1518111, rs3024490, rs3024496, rs3024491) were genotyped in asthmatic subjects and controls using real-time PCR. Tregs cells and IL-10 were analyzed in peripheral blood mononuclear cells by flow cytometry. The severity of asthma was defined according to the Global Initiative for Asthma (GINA) guideline. Results: One hundred twenty-three asthmatic subjects and fifty-eight controls participated in the study. The single nucleotide polymorphism (SNP) rs3024491 (T allele) showed association with asthma severity, presenting a higher frequency in patients in the moderate asthma group. The T allele of variant rs3024491 also showed an association with reduced IL-10 levels (p = 0.01) and with increased Tregs frequency (p = 0.01). The other variants did not present consistent associations. Conclusions: Our results suggest that moderate asthma is associated with a higher frequency of the T allele in the SNP rs3024491. In addition, the variant rs3024491 (TT) was associated with a reduction in IL-10 production and an increased percentage of Tregs cells, suggesting possible mechanisms that influence asthma severity.

Expansion of T regulatory lymphocytes by murine bone marrow dendritic cells previously stimulated with Anisakis simplex larval antigens

BACKGROUND Anisakis simplex antigens present immunomodulatory properties by the induction of tolerogenic dendritic cells (DCs) in mice. OBJECTIVES To study the capacity of DCs stimulated with A. simplex excretory-secretory (ES) or crude extract (CE) to generate Tregs. To investigate in vitro effects of antigens on the metabolic activity of splenocytes induced by LPS or CpG. METHODS Phenotypic and functional characterization of T cells co-cultured with A. simplex-pulsed DCs was performed by flow cytometry. Lymphocyte mitochondrial respiratory activity was estimated by the Alamar Blue® Assay. FINDINGS In C57BL/6J, CD4+CD25-Foxp3+ and CD8+CD25-Foxp3+ populations increased by CE-stimulated-DCs. In BALB/c, CE-stimulated-DCs caused the expansion of CD4+CD25+Foxp3+IL-10+ and CD8+CD25+Foxp3+IL-10+. IFN-γ expression raised in BALB/c CD4+CD25+ and CD4+CD25- for CE and ES, respectively. ES-stimulated-DCs increased CD4+CD25+ Foxp3+ and CD8+CD25- Foxp3+ expression in T cells. The association of ES or CE with LPS produced the increase in splenocyte activity in C57BL/6J. The association of CE with CpG decreased the proliferation caused by CpG in C57BL/6J. MAIN CONCLUSIONS A. simplex increase the frequency of Tregs, which in turn produce IL-10 and IFN-γ. The host genetic base is essential in the development of anti-Anisakis immune responses (Th2, Th1, Treg).

CD4+CD69+ T cells and CD4+CD25+FoxP3+ Treg cells imbalance in peripheral blood, spleen and peritoneal lavage from pristane-induced systemic lupus erythematosus (SLE) mice

Abstract Background: Adaptive immune cells, including CD4+CD69+ and CD4+CD25+FoxP3+ regulatory T (Treg) cells, are important for maintaining immunological tolerance. In human systemic lupus erythematosus (SLE), CD4+CD25+FoxP3+ Treg cells are reduced, whereas CD69 expression is increased, resulting in a homeostatic immune imbalance that may intensify autoreactive T cell activity. To analyze the mechanisms implicated in autotolerance failure, we evaluated CD4+CD69+ and CD4+CD25+FoxP3+ T cells and interleukin profiles in a pristane-induced SLE experimental model. Methods: For lupus induction, 26 female Balb/c mice received a single intraperitoneal 0.5 ml dose of pristane, and 16 mice received the same dose of saline. Blood and spleen samples were collected from euthanized mice 90 and 120 days after pristane or saline inoculation. Mononuclear cells from peripheral blood (PBMC), peritoneal lavage (PL) and splenocytes were obtained by erythrocyte lysis and cryopreserved for further evaluation by flow cytometry using the GuavaEasyCyte TM HT. After thawing, cells were washed and stained with monoclonal antibodies against CD3, CD4, CD8, CD25, CD28, CD69, FoxP3, CD14 and Ly6C (BD Pharmingen TM). Interleukins were quantified using Multiplex® MAP. The Mann-Whitney test and the Pearson coefficient were used for statistical analysis, and p < 0.05 considered significant. Results: Compared with the controls, SLE-induced animals presented increased numbers of CD4+CD69+ T cells in the blood on T90 and T120 (p = 0.022 and p = 0.008) and in the spleen on T120 (p = 0.049), but there were decreased numbers in the PL (p = 0.049) on T120. The percentage of Treg was lower in blood (p < 0.005 and p < 0.012) on T90 and T120, in spleen (p = 0.043) on T120 and in PL (p = 0.001) on T90. Increased numbers of CD4+ CD69+ T cells in the PL were positively associated with high IL-2 (p = 0.486) and IFN-γ (p = 0.017) levels, whereas reduced Treg cells in the blood were negatively correlated with TNFα levels (p = 0.043) and positively correlated with TGFβ1 (p = 0.038). Conclusion: Increased numbers of CD4+CD69+ T cells and reduced numbers of CD4+CD25+FoxP3+ Treg cells with an altered interleukin profile suggests loss of autotolerance in pristane-induced lupus mice, which is similar to human lupus. Therefore, this model is useful in evaluating mechanisms of cellular activation, peripheral tolerance and homeostatic immune imbalance involved in human SLE.

The role of regulatory T cells, interleukin-10 and in vivo scintigraphy in autoimmune and idiopathic diseases - Therapeutic perspectives and prognosis / O papel de células T regulatórias, da interleucina 10 e da cintilografica in vivo em doenças autoimunes e idiopáticas - Perspectivas terapêuticas e prognóstico

Summary Previous studies have demonstrated the expression of the CD25 marker on the surface of naturally occurring T cells (Tregs) of mice, which have a self-reactive cellular profile. Recently, expression of other markers that aid in the identification of these cells has been detected in lymphocyte subtypes of individuals suffering of autoimmune and idiopathic diseases, including: CD25, CTLA-4 (cytotoxic T-lymphocyte antigen 4), HLA-DR (human leukocyte antigen) and Interleukin 10 (IL-10), opening new perspectives for a better understanding of an association between such receptors present on the cell surface and the prognosis of autoimmune diseases. The role of these molecules has already been described in the literature for the modulation of the inflammatory response in infectious and parasitic diseases. Thus, the function, phenotype and frequency of expression of the a-chain receptor of IL-2 (CD25) and IL-10 in lymphocyte subtypes were investigated. Murine models have been used to demonstrate a possible correlation between the expression of the CD25 marker (on the surface of CD4 lymphocytes) and the control of self-tolerance mechanisms. These studies provided support for the presentation of a review of the role of cells expressing IL-2, IL-10, HLA-DR and CTLA-4 receptors in the monitoring of immunosuppression in diseases classified as autoimmune, providing perspectives for understanding peripheral regulation mechanisms and the pathophysiology of these diseases in humans. In addition, a therapeutic approach based on the manipulation of the phenotype of these cells and ways of scintigraphically monitoring the manifestations of these diseases by labeling their receptors is discussed as a perspective. In this paper, we have included the description of experiments in ex vivo regulation of IL-10 and synthesis of thio-sugars and poly-sugars to produce radiopharmaceuticals for monitoring inflammation. These experiments may yield benefits for the treatment and prognosis of autoimmune diseases.

Resumo Estudos anteriores já haviam demonstrado a expressão do marcador CD25 na superfície de células T de ocorrência natural (Tregs) de camundongos, que apresentam perfil celular autorreativo. Recentemente, foi detectada, em subtipos de linfócitos de indivíduos acometidos por doenças autoimunes e de causa idiopática, a expressão de outros marcadores, que auxiliam na identificação dessas células, entre os quais: CD25, CTLA-4 (cytotoxic T-lymphocyte antigen 4), HLA-DR (human leucocyte antigen) e Interleucina 10 (IL-10), abrindo novas perspectivas para a melhor compreensão de uma associação entre esses receptores presentes na superfície celular e o prognóstico de doenças autoimunes. O papel dessas moléculas já havia sido descrito na literatura na modulação da resposta inflamatória em doenças infectoparasitárias. Dessa forma, foram investigados a função, o fenótipo e a frequência de expressão, do receptor de cadeia a da IL-2 (CD25) e de IL-10 em subtipos de linfócitos. O modelo murino tem sido utilizado para demonstrar uma possível correlação entre a expressão do marcador CD25 (na superfície de linfócitos CD4) e o controle dos mecanismos de autotolerância. Essas pesquisas forneceram suporte para apresentação de uma revisão sobre o papel das células que expressam os receptores de IL-2, IL-10, HLA-DR e CTLA-4 no monitoramento da imunossupressão, em doenças de classificação autoimune, abrindo perspectivas para o entendimento dos mecanismos de regulação periférica e sobre a fisiopatologia dessas doenças no ser humano. Além disso, é discutida como perspectiva uma abordagem terapêutica fundamentada na manipulação do fenótipo dessas células, bem como de modos de monitoramento cintilográfico das manifestações dessas doenças, por meio da marcação de seus receptores. Nestes, foram incluídas descrições das experiências em regulação ex-vivo de IL-10; de síntese de tioaçúcares e de poliaçúcares para produção de radiofármacos para monitoramento de inflamações. Essas experiências podem trazer benefícios na terapia e no prognóstico de doenças autoimunes.

Unbalanced expression of aryl hydrocarbon receptor in peripheral blood CCR6+CD4+ and CD4+CD25+T cells of rheumatoid arthritis / Expressão não equilibrada do receptor de hidrocarboneto arílico nos linfócitos T CCR6+ CD4+ e CD4+ CD25+ do sangue periférico na artrite reumatoide

ABSTRACT Objective: The goal of this study was to analyze the role of aryl hydrocarbon receptor in peripheral blood CCR6+CD4+ and CD4+CD25+T cells of patients with rheumatoid arthritis. Methods: Flow cytometry was applied to determine the proportion of AhR positive cells in CCR6+CD4+T, CD4+CD25+T and peripheral blood peripheral mononuclear cells from each subject. AhR mRNA and CYP1A1 mRNA relative expression levels were tested by real-time PCR. Results: The percentage of AhR positive cells in peripheral blood mononuclear cells was higher in RA group than that in healthy cases [(35.23 ± 10.71)% vs. (18.83 ± 7.32)%, p < 0.01]. The expression levels of AhR and CYP1A1 were both increased in patients with RA while compared to controls [(3.71 ± 1.63) vs. (2.00 ± 1.27), p = 0.002; (2.62 ± 2.08) vs. (0.62 ± 0.29), p < 0.01, respectively]. In RA patients, the percentage of AhR positive cells in CD4+CD25+T cells was significantly lower than that from controls [17.90 (6.10 ± 80.10)% vs. (52.49 ± 19.18)%, p < 0.01]; In healthy controls, the percentage of AhR positive cells in CD4+CD25+T cells was significantly higher than that in CCR6+CD4+T cells, and was also significantly higher than that in PBMCs [(52.49 ± 19.18)% vs. (23.18 ± 5.62)% vs. (18.06 ± 7.80)%, X 2 = 24.03, p < 0.01]; in RA patients, the percentage of AhR positive cells in CCR6+CD4+T cells was significantly increased than that in CD4+CD25+T cells and PBMCs [(46.02 ± 14.68)% vs. 17.90 (6.10 ± 80.10)% vs. (34.22 ± 10.33)%, X 2 = 38.29, p < 0.01]; Nevertheless, no statistically significant relationship was found between clinical data and AhR positive cells in CCR6+CD4+T and CD4+CD25+T cells. Conclusion: AhR may participate in the pathological progress of RA by controlling the differentiation of Th17 and Treg cells in peripheral blood.

RESUMO Objetivo: Analisar o papel do receptor de hidrocarboneto arílico (AhR) nos linfócitos T CCR6+ CD4+ e CD4+ CD25+ no sangue periférico de pacientes com artrite reumatoide (AR). Métodos: Foi aplicada citometria de fluxo para determinar a proporção de células AhR positivas em linfócitos CCR6+ CD4+ e CD4+ CD25+ do sangue periférico e células mononucleares periféricas de cada indivíduo. Os níveis de expressão relativa de ácido ribonucleico mensageiro (do inglês ribonucleic acid, RNAm,) de AhR e RNAm de enzima de primeiro estágio essencial para o AhR (CYP1A1) foram testados por reação em cadeia de polimerase (do inglês polymerase chain reaction, PCR,) em tempo real. Resultados: A percentagem de células AhR positivas nas células mononucleares do sangue periférico foi maior no grupo com AR do que nos indivíduos saudáveis [(35,23 ± 10,71)% vs. (18,83 ± 7,32)%, (p < 0,01)]. Os níveis de expressão de AhR e CYP1A1 estavam aumentados em pacientes com AR quando comparados com os controles [(3,71 ± 1,63) vs. (2,00 ± 1,27), p = 0,002; (2,62 ± 2,08) vs. (0,62 ± 0,29), p < 0,01, respectivamente]. Em pacientes com AR, a percentagem de células AhR positivas nos linfócitos T CD4+ CD25+ foi significativamente inferior à dos controles [17,90 (6,10 ± 80,10)]% vs. (52,49 ± 19,18)%, p < 0,01]; em controles saudáveis, a percentagem de células AhR positivas nos linfócitos T CD4+ CD25+ foi significativamente mais elevada do que nos linfócitos T CCR6+ CD4+ e também foi significativamente maior do que nas células mononucleares do sangue periférico (do inglês peripheral blood mononuclear cells, PBMC,) [(52,49 ± 19,18)% vs. (23,18 ± 5,62)% vs. (18,06 ± 7,80)%, X 2 = 24,03, p < 0,01]; em pacientes com AR, a percentagem de células AHR positivas nos linfócitos T CCR6+ CD4+ era significativamente maior em comparação com os linfócitos T CD4+ CD25+ e PBMC (46,02 ± 14,68)% vs. [17,90 (6,10 ± 80.10)]% vs. (34,22 ± 10,33)%, X2 = 38,29, p < 0,01]; no entanto, não foi encontrada correlação estatisticamente significativa entre os dados clínicos e células AhR positivas em linfócitos T CCR6+ CD4+ e CD4+ CD25+. Conclusão: O Ahr pode participar do progresso patológico da AR ao controlar a diferenciação de linfócitos Th17 e Treg no sangue periférico.