RESUMO
To control immune responses, regulatory CD4+CD25+Foxp3+ T cells (Treg) maintain their wide and diverse repertoire through continuous arrival of recent thymic emigrants (RTE). However, during puberty, the activity of RTE starts to decline as a natural process of thymic involution, introducing consequences, not completely described, to the repertoire. Type 1 diabetes (T1D) patients show quantitative and qualitative impairments on the Treg cells. Our aim was to evaluate peripheral Treg and RTE cell frequencies, in T1D patients from two distinct age groups (young and adults) and verify if HLA phenotypes are concomitant associated. To this, blood samples from Brazilian twenty established T1D patients (12 young and 8 adults) and twenty-one healthy controls (11 young and 10 adults) were analyzed, by flow cytometry, to verify the percentages of CD4, Treg (CD4+CD25+Foxp3+) and the subsets of CD45RA+ (naive) and CD31+(RTE) within then. Furthermore, the HLA typing was also set. We observed that the young established T1D patients feature decreased frequencies in total Treg cells and naive RTE within Treg cells. Significant prevalence of HLA alleles, associated with risk, in T1D patients, was also identified. Performing a multivariate analysis, we confirmed that the cellular changes described offers significant variables that distinct T1D patients from the controls. Our data collectively highlight relevant aspects about homeostasis imbalances in the Treg cells of T1D patients, especially in young, and disease prognosis; that might contribute for future therapeutic strategies involving Treg cells manipulation.
Assuntos
Diabetes Mellitus Tipo 1 , Fatores de Transcrição Forkhead , Subunidade alfa de Receptor de Interleucina-2 , Linfócitos T Reguladores , Timo , Humanos , Diabetes Mellitus Tipo 1/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Adulto , Brasil , Masculino , Feminino , Fatores de Transcrição Forkhead/metabolismo , Timo/imunologia , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Adulto Jovem , Adolescente , Imunofenotipagem , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , CriançaRESUMO
Sodium selenite modulates the activity of lymphocytes. It negatively regulates the suppressive activity of cells and increases the immune response. In this study, we evaluated whether the regulatory T cell differentiation was modulated by sodium selenite. The percentages of CD4+CD25+Foxp3+, CD4+CD25+, and CD4+CTLA-4+ cells in CD4+ T cells cultures stimulated with IL-2 and TGF-ß in the presence or absence of selenium, in the form of sodium selenite (2.0×10-6M), were evaluated by flow cytometry. The mRNA expression of TET2/3 enzymes and IL-10 was analyzed by RT-qPCR and the levels of IL-10 were measured by an ELISA. We observed a decrease in CD4+CD25+Foxp3+ and CD4+CTLA-4+ cells in presence of selenium. However, normal percentages were reached again after selenium removal. An increase in CD4+CTL4-4+ cells was detected in selenium-primed cell cultures in absence of IL-2 and TGF-ß. In addition, we observed a decrease in TET3 in presence of selenium. Finally, we observed an augment in IL-10 transcription and protein levels and relative expression of TET2 in cultures exposed to selenium. We suggest that selenium reversibly affects the regulatory T cell differentiation in vitro. Likewise, selenium may modulate Treg percentages promoting optimal immune responses and, at the same time, the expression of specific suppressor molecules.
Assuntos
Interleucina-10 , Selênio , Linfócitos T Reguladores/metabolismo , Selenito de Sódio/farmacologia , Selenito de Sódio/metabolismo , Antígeno CTLA-4/metabolismo , Selênio/farmacologia , Selênio/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Diferenciação Celular , Fatores de Transcrição Forkhead/metabolismo , Subunidade alfa de Receptor de Interleucina-2/genética , Subunidade alfa de Receptor de Interleucina-2/metabolismoRESUMO
STAT3 is a cytokine-signaling transcription factor critical for gene regulation. Gain-of-function (GOF) mutations in STAT3 are associated with lymphoproliferation, autoimmune cytopenias, increased susceptibility to infection, early-onset solid-organ autoimmunity, short stature, and eczema. We studied the JAK/STAT signaling pathway gene expression and the cytokine profile in two families carrying STAT3-GOF variants to shed light on the STAT3-GOF-associated variable expressivity, including the identification of disease markers. Considering 92 target genes, KIT and IL2RA were downregulated only in patients with high clinical penetrance, while CXCL8 was markedly downregulated for all of them. Unlike previous studies, SOCS3-a STAT3 inhibitor-was not upregulated in patients. In addition, low levels of IL-2 and a reduced numbers of Tregs cells were strikingly prevalent in patients. This study shows a disruptive role of STAT3-GOF variants in the regulatory axis activities CXCL8/STAT3, KIT/STAT3, IL2/CD25/Treg, which, by slightly different mechanisms, underlie the broad clinical spectrum seen in the studied patients. In addition, we suggest the investigation of CXCL8 as a biomarker for identifying STAT3-GOF mutation.
Assuntos
Mutação com Ganho de Função , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Interleucina-2/metabolismo , Interleucina-8/metabolismo , Fator de Transcrição STAT3/genética , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Adulto , Pré-Escolar , Hibridização Genômica Comparativa , Citocinas/sangue , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Imunofenotipagem , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Sequenciamento do Exoma , Sequenciamento Completo do GenomaRESUMO
BACKGROUND: Regulatory T cells (Tregs) play a critical role during Mycobacterium tuberculosis (Mtb) infection, modulating host responses while neutralizing excessive inflammation. However, their impact on regulating host protective immunity is not completely understood. Here, we demonstrate that Treg cells abrogate the in vitro microbicidal activity against Mtb. METHODS: We evaluated the in vitro microbicidal activity of peripheral blood mononuclear cells (PBMCs) from patients with active tuberculosis (TB), individuals with latent tuberculosis infection (LTBI, TST+/IGRA+) and healthy control (HC, TST-/IGRA-) volunteers. PBMCs, depleted or not of CD4+CD25+ T-cells, were analyzed to determine frequency and influence on microbicidal activity during in vitro Mtb infection with four clinical isolates (S1, S5, R3, and R6) and one reference strain (H37Rv). RESULTS: The frequency of CD4+CD25highFoxP3+ cells were significantly higher in Mtb infected whole blood cultures from both TB patients and LTBI individuals when compared to HC. Data from CD4+CD25+ T-cells depletion demonstrate that increase of CD4+CD25highFoxP3+ is associated with an impairment of Th-1 responses and a diminished in vitro microbicidal activity of LTBI and TB groups. CONCLUSIONS: Tregs restrict host anti-mycobacterial immunity during active disease and latent infection and thereby may contribute to both disease progression and pathogen persistence.
Assuntos
Atividade Bactericida do Sangue , Antígenos CD4/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Tuberculose Latente/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/imunologia , Antígenos CD4/genética , Estudos de Casos e Controles , Fatores de Transcrição Forkhead/genética , Humanos , Subunidade alfa de Receptor de Interleucina-2/genética , Linfócitos T ReguladoresRESUMO
BACKGROUND: The treatment of latent tuberculosis infection (LTBI) in individuals at risk of reactivation is essential for tuberculosis control. However, blood biomarkers associated with LTBI treatment have not been identified. METHODS: Blood samples from tuberculin skin test (TST) reactive individuals were collected before and after one and six months of isoniazid (INH) therapy. Peripheral mononuclear cells (PBMC) were isolated, and an in-house interferon-γ release assay (IGRA) was performed. Expression of chemokine ligand 4 (CCL4), chemokine ligand 10 (CXCL10), chemokine ligand 11 (CXCL11), interferon alpha (IFNA), radical S-adenosyl methionine domain-containing 2 (RSAD2), ubiquitin-specific peptidase 18 (USP18), interferon-induced protein 44 (IFI44), interferon-induced protein 44 like (IFI44L), interferon-induced protein tetratricopeptide repeats 1(IFIT1), and interleukin 2 receptor subunit alpha (IL2RA) mRNA levels were assessed by qPCR before, during, and after INH treatment. RESULTS: We observed significantly lower relative abundances of USP18, IFI44L, IFNA, and IL2RA transcripts in PBMC from IGRA-positive individuals compared to levels in IGRA-negative individuals before INH therapy. Also, relative abundance of CXCL11 was significantly lower in IGRA-positive than in IGRA-negative individuals before and after one month of INH therapy. However, the relative abundance of CCL4, CXCL10, and CXCL11 mRNA was significantly decreased and that of IL2RA and USP18 significantly increased after INH therapy, regardless of the IGRA result. Our results show that USP18, IFI44L, IFIT1, and IL2RA relative abundances increased significantly, meanwhile the relative abundance of CCL4, CXCL11, and IFNA decreased significantly after six months of INH therapy in TST-positive individuals. CONCLUSIONS: Changes in the profiles of USP18, IL2RA, IFNA, CCL4, and CXCL11 expressions during INH treatment in TST-positive individuals, regardless of IGRA status, are potential tools for monitoring latent tuberculosis treatment.
Assuntos
Expressão Gênica , Subunidade alfa de Receptor de Interleucina-2/genética , Tuberculose Latente/genética , Tuberculose Latente/microbiologia , Ubiquitina Tiolesterase/genética , Adulto , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Biomarcadores , Feminino , Humanos , Testes de Liberação de Interferon-gama , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Isoniazida/farmacologia , Isoniazida/uso terapêutico , Tuberculose Latente/diagnóstico , Tuberculose Latente/tratamento farmacológico , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Teste Tuberculínico , Ubiquitina Tiolesterase/metabolismo , Adulto JovemRESUMO
INTRODUCTION: Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), is the fourth most important tropical disease, which affects approximately 7 million people worldwide. The mechanisms involved in the development of this disease are not completely well understood. An important protective role of regulatory T cells (Treg) in Chagas disease has been observed; however, the specific mechanisms remain unclear. We evaluated apoptosis as a possible mechanism mediated by Treg cells (CD4+CD25HighFOXP3+) to orchestrate the immune response in chronic Chagas disease. METHODS AND RESULTS: Patients with Chagas disease were grouped as the indeterminate (IND; asymptomatic patients with Chagas disease; nâ¯=â¯10) and dilated cardiomyopathy (CARD; nâ¯=â¯10). Healthy T. cruzi-negative individuals (NI; nâ¯=â¯10) were included as a control group. In order to evaluate the apoptotic cell profile, the expression of PD1, PD1L, CD39, CD95, CD95L molecules were investigated. We also evaluated the proportion of CD14+ cells expressing caspase 3. The IND group presented a substantially higher expression of CD39 by Treg cells as compared to the CARD group. On the other hand, the CARD group showed higher expression of PD-1 by Treg cells than both NI and IND groups. Significant positive correlations were observed between Treg CD95L+ cells and CD14 cells expressing caspase 3 as well as between Treg CD39 cells and CD14+ Caspase3+ cells in the IND group. CONCLUSION: Our data indicate that the expressions of different molecules that induce apoptosis are associated with suppressive mechanisms mediated by Treg cells and suggest a possible role for PD1 and PDL1 molecules in the morbidity of chronic Chagas disease.
Assuntos
Antígeno B7-H1/metabolismo , Cardiomiopatia Dilatada/sangue , Cardiomiopatia Chagásica/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T Reguladores/imunologia , Trypanosoma cruzi/imunologia , Adulto , Idoso , Antígenos de Protozoários/imunologia , Apoptose/imunologia , Apirase/metabolismo , Antígenos CD4/metabolismo , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Masculino , Pessoa de Meia-Idade , Testes SorológicosRESUMO
Obesity is a chronic disease associated with different metabolic diseases as well as alterations in immune cell function. It is characterized by a chronic systemic low grade inflammation. There are several studies demonstrating the influence of obesity on the impaired immune response to infection. However, it is not completely clear whether the obese environment influences the development or maintenance of the immune response against infections. The aim of this study was to determine how obesity induced by a high-fat diet affects the immune response to an early oral Salmonella infection. Four groups of mice were kept in separate cages. Two of these designated as controls, fed with a normal diet; whereas other two groups were fed with a high fat diet for 10 weeks. Some mice were used for Salmonella oral infection. After 7 days of oral infection with S. Thypimurium the proportions of spleen cell subsets expressing activation markers in normal diet and HFD obese mice were stained with monoclonal antibodies and analyzed by flow cytometry. Also, mRNA levels of different cytokines were quantified by RT-PCR. It was found that obesity affects the function of the immune system against an early oral Salmonella infection, decreasing NK cells, altering the expression of activation molecules as well as cytokines mRNA levels. Interestingly, the expression some activation molecules on T lymphocytes was reestablished after Salmonella infection, but not the CD25 expression. Immune alterations could lead to immunosuppression or increased susceptibility to infections in HFD obese mice.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Imunidade , Camundongos Obesos/imunologia , Doenças da Boca/microbiologia , Obesidade/imunologia , Infecções por Salmonella/imunologia , Salmonella typhimurium/patogenicidade , Animais , Carga Bacteriana , Peso Corporal , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Terapia de Imunossupressão , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Células Matadoras Naturais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Salmonella typhimurium/imunologia , Baço/imunologia , Linfócitos TRESUMO
Immune homeostasis has been suggested to play an important role in the clinical evolution of chronic Chagas disease; however, the immunopathologic factors involved have not been fully elucidated. Therefore, our study aimed to analyse the frequency of CD4+ CD25+ FoxP3+ cells, classic Th17 cells, alternative Th17 cells and IL-17+ B cells from peripheral blood of chronic cardiac patients after in vitro stimulation with Trypanosoma cruzi soluble EPI antigen. Patients were selected and classified according to clinical evaluation of cardiac involvement: mild, B1 (CARD1) (n = 20) and severe, C (CARD2) (n = 11). Patients with the indeterminate form of CD were included as the control group A (IND) (n = 17). Blood samples were collected and cultured in the presence of EPI antigen. Cells frequency and median fluorescence intensity (MFI) were obtained by flow cytometry. Our results showed that only CD4+ CD25+ FoxP3+ , CD4+ CD25high FoxP3+ , CD4+ IL-17+ IFN-γ- and CD4+ IL-17+ IFN-γ+ cells are more frequent in patients with severe cardiac disease and correlate with worse global cardiac function. However, while indeterminate patients demonstrated a positive correlation between CD4+ CD25+ FoxP3+ and CD4+ IL-17+ IFN-γ- Th17 cells, this relationship was not observed in cardiac patients. IL-17 expression by Th17 cells and B cells correlated with disease progression. Altogether our results suggest that the clinical progression of Chagas cardiomyopathy involves worsening of inflammation and impairment of immunoregulatory mechanisms.
Assuntos
Subpopulações de Linfócitos B/imunologia , Cardiomiopatia Chagásica/patologia , Fatores de Transcrição Forkhead/metabolismo , Coração/fisiopatologia , Interleucina-17/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Células Th17/imunologia , Subpopulações de Linfócitos B/classificação , Células Cultivadas , Feminino , Humanos , Inflamação/patologia , Interferon gama/imunologia , Masculino , Células Th17/classificação , Trypanosoma cruzi/imunologia , Função Ventricular Esquerda/fisiologiaRESUMO
Regulatory T cells (Tregs) are known to control immune responses by suppressing the antigen-presenting and effector T cells. Some mechanisms adopted by Tregs in combating Mycobacterium infections have been proposed. Nevertheless, in M. leprae infection, also known as leprosy or Hansen's disease, the role of Tregs has not been completely elucidated. Using multicolor flow cytometry, we evaluated the expression of different cell surface and intracellular molecules present in Tregs from peripheral blood samples of leprosy patients. Before initiating treatment, thirteen new cases of leprosy were grouped according to the Ridley-Jopling classification in to the paucibacilary (PB) or multibacilary (MB) group. Fifteen non-infected individuals (NI) were included as control subjects. Tregs were higher in the MB group than in the NI group. Tregs also co-expressed high amounts of PD1 and PDL-1, indicating that these cells could induce apoptosis of effector cells and simultaneously prevent their own apoptosis. Our data showed that compared to the NI group, Tregs from the PB group expressed higher levels of CD95L, which may be associated with other apoptotic pathways that may decrease Tregs in these patients. Correlation analysis reinforced that PD1 and CD95L are efficient apoptosis' pathway that decreased levels of Tregs in the NI and PB groups. We also observed significant differences in cytokine expression of Tregs from the PB and MB groups. Compared to the NI group, Tregs from the MB group showed higher IL-17 expression; however, compared to the PB group, the expression of IL-10 in Tregs from the MB group was lower, suggesting inefficient control of inflammation. Therefore, we concluded that different pathways were involved in Treg-induced suppression of leprosy. Moreover, Treg-mediated regulation of inflammation via IL-10 and IL-17 expression in leprosy patients was inefficient. Thus, we propose that during M. leprae infection, Tregs may impair the immune responses elicited against this bacillus, favor bacterial replication, and aid in persistence of a disseminated multibacillary disease.
Assuntos
Células Sanguíneas/imunologia , Hanseníase/imunologia , Mycobacterium leprae/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Apoptose , Antígeno B7-H1/metabolismo , Células Cultivadas , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Fator de Transcrição Ikaros/metabolismo , Imunofenotipagem , Interleucina-10/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Masculino , Receptor de Morte Celular Programada 1/metabolismoRESUMO
PROBLEM: Breastfeeding's influence on the tolerance to environmental antigens is essential for short- and long-term homeostasis for children. Colostrum is rich in leucocytes, but it is unknown whether regulatory T cells (Treg) account for part of this cell population. METHOD OF STUDY: Frequencies of CD127- CD25++ Treg and levels of immunoregulatory-associated cell markers were determined in colostrum and were compared with autologous blood cells. In addition, we evaluated whether the birth conditions can affect these features. RESULTS: Higher frequencies of CD127 - CD25++ Treg cells expressing Foxp3 and CD45RO were observed in the colostrum. The cells' CD25, CD152, CD279, and TGF-ß expression levels were greater than those in autologous blood cells. In addition, the CD279 and TGF-ß expressions of colostrum CD127- CD25++ Treg cells were influenced by gestational age and delivery mode. CONCLUSION: The higher proportion of these cells with a function-associated phenotype may reflect certain tolerogenic effects of breastmilk on newborns and infants, contributing to immune system homeostasis.