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Tamoxifen (TAM) is widely utilized in the prevention and treatment of human breast cancer and has demonstrated the potential to modulate the immune response. It has been proposed as a therapeutic tool for immune-mediated diseases. TAM has been investigated as a possible treatment for asthma-like conditions in horses, revealing specific impacts on the innate immune system. While the effects of TAM on equine neutrophils are well-documented, its influence on lymphocytes and the modulation of the immune response polarization remains unclear. This in vitro study employed peripheral blood mononuclear cells (PBMC) from healthy horses, exposing them to varying concentrations of the TAM and assessing the expression of genes involved in the polarization of the immune response (TBX21, IFNG, GATA3, IL4, IL10, FOXP3, and CTLA4) in PBMC stimulated or not with PMA/ionomycin. Additionally, the effect of TAM over the proportion of regulatory T cells (Treg) was also assessed. TAM did not significantly affect the expression of these genes and Treg at low concentrations. However, at the highest concentration, there was an impact on the expression of GATA3, IL4, IL10, and CTLA4 genes. These alterations in genes associated with a Th2 and regulatory response coincided with a noteworthy increase in drug-associated cytotoxicity but only at concentrations far beyond those achieved in pharmacological therapy. These findings suggest that the effects of TAM, as described in preclinical studies on asthmatic horses, may not be attributed to the modification of the adaptive response.
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The mechanisms that negatively regulate inflammation upon a pathogenic stimulus are crucial for the maintenance of tissue integrity and organ function. T regulatory cells are one of the main drivers in controlling inflammation. The ability of T regulatory cells to adapt to different inflammatory cues and suppress inflammation is one of the relevant features of T regulatory cells. During this process, T regulatory cells express different transcription factors associated with their counterparts, Th helper cells, including Tbx21, GATA-3, Bcl6, and Rorc. The acquisition of this transcription factor helps the T regulatory cells to suppress and migrate to the different inflamed tissues. Additionally, the T regulatory cells have different mechanisms that preserve stability while acquiring a particular T regulatory cell subtype. This review focuses on describing T regulatory cell subtypes and the mechanisms that maintain their identity in health and diseases.
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Plasticidade Celular , Linfócitos T Reguladores , Humanos , Linfócitos T Reguladores/imunologia , Animais , Plasticidade Celular/imunologia , Inflamação/imunologia , Inflamação/patologiaRESUMO
The eyes provide themselves with immune tolerance. Frequent skin inflammatory diseases in young blind people suggest, nonetheless, that the eyes instruct a systemic immune tolerance that benefits the whole body. We tested this premise by using delayed skin contact hypersensitivity (DSCH) as a tool to compare the inflammatory response developed by sighted (S) and birth-enucleated (BE) mice against oxazolone or dinitrofluorobenzene at the ages of 10, 30 and 60 days of life. Adult mice enucleated (AE) at 60 days of age were also assessed when they reached 120 days of life. BE mice displayed exacerbated DSCH at 60 but not at 10 or 30 days of age. AE mice, in contrast, show no exacerbated DSCH. Skin inflammation in 60-day-old BE mice was hapten exclusive and supported by distinct CD8+ lymphocytes. The number of intraepidermal T lymphocytes and migrating Langerhans cells was, however, similar between S and BE mice by the age of 60 days. Our observations support the idea that the eyes instruct systemic immune tolerance that benefits organs outside the eyes from an early age. The higher prevalence of inflammatory skin disorders reported in young people might then reflect reduced immune tolerance associated with the impaired functional morphology of the eyes.
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Tuberculosis (TB) caused by the complex Mycobacterium tuberculosis (Mtb) is the main cause of death by a single bacterial agent. Last year, TB was the second leading infectious killer after SARS-CoV-2. Nevertheless, many biological and immunological aspects of TB are not completely elucidated, such as the complex process of immunoregulation mediated by regulatory T cells (Treg cells) and the enzymes indoleamine 2,3-dioxygenase (IDO) and heme oxygenase 1 (HO-1). In this study, the contribution of these immunoregulatory factors was compared in mice infected with Mtb strains with different levels of virulence. First Balb/c mice were infected by intratracheal route, with a high dose of mild virulence reference strain H37Rv or with a highly virulent clinical isolate (strain 5186). In the lungs of infected mice, the kinetics of Treg cells during the infection were determined by cytofluorometry and the expression of IDO and HO-1 by RT-PCR and immunohistochemistry. Then, the contribution of immune-regulation mediated by Treg cells, IDO and HO-1, was evaluated by treating infected animals with specific cytotoxic monoclonal antibodies for Treg cells depletion anti-CD25 (PC61 clone) or by blocking IDO and HO-1 activity using specific inhibitors (1-methyl-D,L-tryptophan or zinc protoporphyrin-IX, respectively). Mice infected with the mild virulent strain showed a progressive increment of Treg cells, showing this highest number at the beginning of the late phase of the infection (28 days), the same trend was observed in the expression of both enzymes being macrophages the cells that showed the highest immunostaining. Animals infected with the highly virulent strain showed lower survival (34 days) and higher amounts of Treg cells, as well as higher expression of IDO and HO-1 one week before. In comparison with non-treated animals, mice infected with strain H37Rv with depletion of Treg cells or treated with the enzymes blockers during late infection showed a significant decrease of bacilli loads, higher expression of IFN-g and lower IL-4 but with a similar extension of inflammatory lung consolidation determined by automated morphometry. In contrast, the depletion of Treg cells in infected mice with the highly virulent strain 5186 produced diffuse alveolar damage that was similar to severe acute viral pneumonia, lesser survival and increase of bacillary loads, while blocking of both IDO and HO-1 produced high bacillary loads and extensive pneumonia with necrosis. Thus, it seems that Treg cells, IDO and HO-1 activities are detrimental during late pulmonary TB induced by mild virulence Mtb, probably because these factors decrease immune protection mediated by the Th1 response. In contrast, Treg cells, IDO and HO-1 are beneficial when the infection is produced by a highly virulent strain, by regulation of excessive inflammation that produced alveolar damage, pulmonary necrosis, acute respiratory insufficiency, and rapid death.
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COVID-19 , Mycobacterium tuberculosis , Tuberculose Pulmonar , Camundongos , Animais , Heme Oxigenase-1 , Mycobacterium tuberculosis/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Linfócitos T Reguladores , Virulência , COVID-19/metabolismo , SARS-CoV-2/metabolismo , Pulmão/microbiologia , Necrose/metabolismoRESUMO
Hypothyroidism exerts deleterious effects on immunity, but the precise role of the hypothalamic-pituitary-thyroid (HPT) axis in immunoregulatory and tolerogenic programs is barely understood. Here, we investigated the mechanisms underlying hypothyroid-related immunosuppression by examining the regulatory role of components of the HPT axis. We first analyzed lymphocyte activity in mice overexpressing the TRH gene (Tg-Trh). T cells from Tg-Trh showed increased proliferation than wild-type (WT) euthyroid mice in response to polyclonal activation. The release of Th1 pro-inflammatory cytokines was also increased in Tg-Trh and TSH levels correlated with T-cell proliferation. To gain further mechanistic insights into hypothyroidism-related immunosuppression, we evaluated T-cell subpopulations in lymphoid tissues of hypothyroid and control mice. No differences were observed in CD3/CD19 or CD4/CD8 ratios between these strains. However, the frequency of regulatory T cells (Tregs) was significantly increased in hypothyroid mice, and not in Tg-Trh mice. Accordingly, in vitro Tregs differentiation was more pronounced in naïve T cells isolated from hypothyroid mice. Since Tregs overexpress galectin-1 (Gal-1) and mice lacking this lectin (Lgals1-/- ) show reduced Treg function, we investigated the involvement of this immunoregulatory lectin in the control of Tregs in settings of hypothyroidism. Increased T lymphocyte reactivity and reduced frequency of Tregs were found in hypothyroid Lgals1-/- mice when compared to hypothyroid WT animals. This effect was rescued by the addition of recombinant Gal-1. Finally, increased expression of Gal-1 was found in Tregs purified from hypothyroid WT mice compared with their euthyroid counterpart. Thus, a substantial increase in the frequency and activity of Gal-1-expressing Tregs underlies immunosuppression associated with hypothyroid conditions, with critical implications in immunopathology, metabolic disorders, and cancer.
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Hipotireoidismo , Tireotropina , Camundongos , Animais , Tireotropina/metabolismo , Hormônio Liberador de Tireotropina/farmacologia , Linfócitos T Reguladores/metabolismo , Galectina 1/genética , Hipotireoidismo/metabolismo , Terapia de ImunossupressãoRESUMO
Abstract Introduction/objectives Systemic lupus erythematosus (SLE) is a classic prototype of the multisystem autoimmune disease and follows a relapsing and remitting course. Triptolide is a diterpene triepoxide extracted from Chinese medicine Tripterygium wilfordii Hook F, with potent immunosuppressive and anti-inflammatory properties. Our previous work observed that triptolide alleviated lupus in MRL/lpr lupus mice with the upregulation of regulatory T cells (Treg) proportion in previous study. In this study, we explored the proportion of follicular T regulatory (Tfr), follicular T helper (Tfh) and germinal center (GC) B cells in lupus mice and evaluated the efficacy of triptolide for lupus treatment in vivo. Methods 20 female MRL/lpr mice were randomly divided into 2 treatment groups and treated orally with vehicle or triptolide. C3H mice were all housed as controlled group and treated orally with vehicle. The percentage of Tfr cells, Tfh cells and GC B cells in spleen of mice were detected by Flow cytometric analysis and immunohistochemistry after 13 weeks of treatment. Results We found that the percentage of Tfr cells decreased in MRL/lpr mice compared with controlled mice. The percentage of Tfh cells in MRL/lpr mice was significantly higher compared with that in controlled mice. The ratio of Tfr/Tfh is also decreased in lupus mice. After treated with triptolide in MRL/Lpr mice in vivo, the percentage of Tfr cells and ratio of Tfr/Tfh increased. The proportion of GC B cells also decreased in mice treated with triptolide by FACS and immunohistochemistry. Conclusions Our results demonstrate that the effect of triptolide in alleviating lupus is partly by reversing immune imbalance with increased percentage of Tfr cells and ratio of Tfr/Tfh. Triptolide might also has effect on immune response through inhibiting proliferating GC B cells.
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Muscle injuries are frequent in individuals with genetic myopathies and in athletes. Skeletal muscle regeneration depends on the activation and differentiation of satellite cells present in the basal lamina of muscle fibers. The skeletal muscle environment is critical for repair, metabolic and homeostatic function. Regulatory T cells (Treg) residing within skeletal muscle comprise a distinct and special cell population that modifies the inflammatory environment by secreting cytokines and amphiregulin, an epidermal growth factor receptor (EGFR) ligand that acts directly upon satellite cells, promoting tissue regeneration. This systematic review summarizes the current knowledge regarding the role of Treg in muscle repair and discusses their therapeutic potential in skeletal muscle injuries. A bibliographic search was carried out using the terms Treg and muscle regeneration and repair, covering all articles up to April 2021 indexed in the PubMed and EMBASE databases. The search included only published original research in human and experimental animal models, with further data analysis based on the PICO methodology, following PRISMA definitions and Cochrane guidelines.
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Doenças Musculares , Linfócitos T Reguladores , Animais , Diferenciação Celular/fisiologia , Humanos , Fibras Musculares Esqueléticas , Músculo Esquelético , CicatrizaçãoRESUMO
Inflammation causes severe dysregulation of organ functions, via the development of oxidative stress and inflammation damage. Polyphenol compounds found in green tea (GTE), including the most important component epigallocatechin-3-gallate (EGCG), have a great therapeutic potential. Here, protective properties of GTE and EGCG against lipopolysaccharide (LPS)-induced inflammation are explored. To this end, the effects of GTE and EGCG were studied on LPS challenged macrophages. Mice received GTE (250 mg/kg/d/p.o) or EGCG (25 mg/kg/d/i.p.) for 7 d, before the inflammation shock was provoked with a single intraperitoneal injection of LPS. The frequencies of lymphocytes CD4+, CD8+, NK1-1+ and CD4+CD25highFOXP3+ (Treg), macrophages CD11b+F480+, monocytes CD11b+Ly6Clow/high, neutrophils CD11b+Ly6G+, MDSCs CD11b+Gr-1high, M2/N2-like phenotype CD206+ and M1-like phenotype CD86+ in spleen, bone marrow and peripheral blood were determined. In vitro studies revealed that GTE and EGCG significantly attenuated LPS-induced CD80 expression and increased the CD163 expression, showing a potential to reduce the macrophage inflammatory phenotype. In vivo, GTE and EGCG inhibited the inflammation, mainly by reducing M1-macrophages and increasing Treg cells in the bone marrow. In addition, GTE and EGCG increase M2-macrophages, N2-neutrophils and Tregs in the spleen and blood and block the migration of monocytes from the bone marrow to the peripheral blood. These findings indicate that EGCG and GTE prevent LPS-induced inflammatory damage contributing to restoring the immune system homeostasis.
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Catequina/análogos & derivados , Inflamação/imunologia , Inflamação/terapia , Linfócitos/imunologia , Macrófagos/imunologia , Chá , Animais , Catequina/farmacologia , Humanos , Lipopolissacarídeos/imunologia , Ativação de Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células Mieloides/imunologia , Substâncias ProtetorasRESUMO
BACKGROUND: Although the literature shows that an increase in both the number and suppressive function of CD4+forkhead box P3 (FOXP3)+ T-regulatory cells (Tregs) during sepsis contributes to an immunosuppressed state, little is known about the identity of these cells. METHODS: Using the sepsis mouse model of cecal ligation and puncture (CLP), we analyzed the frequency and molecular signature of the T-cell immunoglobulin and ITIM domain (TIGIT)+ and TIGIT- Treg subsets, using flow cytometry and quantitative polymerase chain reaction. In addition, ST2-/- and signal transducer and activator of transcription 6 (STAT6)-/- mice were submitted to CLP or recombinant interleukin 33 (IL-33) treatment to investigate the mechanism whereby TIGIT+ Tregs differentiate during sepsis. RESULTS: Sepsis was marked by the sustained expansion of the highly suppressive TIGIT+ Treg subset, which expresses Helios, neuropilin 1, and high levels of Tnfrsf18 and Pdcd1 at 15 days after CLP. The increase in TIGIT+ Tregs was accompanied by higher susceptibility to nosocomial bacteria challenge, suggesting their association with post sepsis immunosuppression. Mechanistically, we found that the ST2 deletion abrogated the expansion of the TIGIT+ Treg subset during sepsis. Furthermore, treatment with recombinant IL-33 resulted in the expansion of TIGIT+ Tregs depending on the STAT6 and M2 macrophages. CONCLUSIONS: These findings demonstrated that only the TIGIT+ Tregs remain stably expanded at the late phase of sepsis. Moreover, the expansion of TIGIT+ Tregs is dependent on the IL-33/ST2/STAT6/M2 macrophage axis.
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Sepse , Linfócitos T Reguladores , Animais , Fatores de Transcrição Forkhead/genética , Terapia de Imunossupressão , Proteína 1 Semelhante a Receptor de Interleucina-1 , Interleucina-33 , Camundongos , Receptores Imunológicos/genéticaRESUMO
It is widely held that schizophrenia involves an active process of peripheral inflammation that induces or reflects brain inflammation with activation of microglia, the brain's resident immune cells. However, recent in vivo radioligand binding studies and large-scale transcriptomics in post-mortem brain report reduced markers of microglial inflammation. The findings suggest a contrary hypothesis; that microglia are diverted into their non-inflammatory synaptic remodelling phenotype that interferes with neurodevelopment and perhaps contributes to the relapsing nature of schizophrenia. Recent discoveries on the regulatory interactions between micro- and astroglial cells and immune regulatory T cells (Tregs) cohere with clinical omics data to suggest that: i) disinhibited astrocytes mediate the shift in microglial phenotype via the production of transforming growth factor-beta, which also contributes to the disturbances of dopamine and GABA function in schizophrenia, and ii) systemically impaired functioning of Treg cells contributes to the dysregulation of glial function, the low-grade peripheral inflammation, and the hitherto unexplained predisposition to auto-immunity and reduced life-expectancy in schizophrenia, including greater COVID-19 mortality.
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COVID-19 , Esquizofrenia , Astrócitos , Humanos , Microglia , SARS-CoV-2 , Linfócitos T ReguladoresRESUMO
Health assessments were conducted on bottlenose dolphins in Barataria Bay, Louisiana, USA, during 2011 to 2018, to assess potential health effects following the Deepwater Horizon oil spill, compared to the unoiled Sarasota Bay, Florida, USA, reference dolphin population. We previously reported significant increases in T-lymphocyte proliferation, as well as lower T helper 1 (Th1) cytokines, higher Th2 cytokine IL-4, and lower T regulatory (Treg) cytokine IL-10 in Barataria Bay in 2011 compared to Sarasota Bay, consistent with Deepwater Horizon oil exposure. Although values between 2013 and 2016 were more similar to those observed in Sarasota Bay, T-cell proliferation was again elevated and cytokine balance tilted toward Th2 in Barataria Bay during 2017-2018. In 2018, Barataria Bay dolphins had significantly more circulating Treg cells than Sarasota Bay dolphins. Mice experimentally exposed to oil also had significantly increased T-lymphocyte proliferation and circulating Treg cell number, including effects in their unexposed progeny. In vitro stimulation resulted in greater Th2 responsiveness in Barataria Bay compared to Sarasota Bay dolphins, and in vitro oil exposure of Sarasota Bay dolphin cells also resulted in enhanced Th2 responsiveness. Evidence points to Treg cells as a potential target for the immunomodulatory effects of oil exposure. The immunological trends observed in Barataria Bay appeared exaggerated in dolphins born after the spill, suggesting the possibility of continued oil exposure or multigenerational health consequences of exposure to oil, as observed in mice. Environ Toxicol Chem 2021;40:1308-1321. © 2021 SETAC.
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Golfinho Nariz-de-Garrafa , Poluição por Petróleo , Animais , Florida , Golfo do México , Louisiana , CamundongosRESUMO
BACKGROUND: The histamine H4 receptor (H4R) is preferentially expressed in immune cells and is a potential therapeutic target for inflammatory and autoimmune diseases. This study aimed at further exploring the role of H4R in the immunobiology of breast cancer. METHODS: We used wild type (WT) and H4R deficient mice (KO) to evaluate whether H4R genotypes show a different distribution of T cell subsets in spleens, tumours and tumour draining lymph nodes (TDLN) in a syngeneic ErbB2-positive breast cancer model developed orthotopically with LM3 cells and its impact on tumour growth. RESULTS: The presence of tumours had a differential impact on the distribution of T cells in TDLN from KO mice compared to WT ones. At day 21 post-inoculation (p.i.) of cells, despite no significant changes in the tumour weight, TDLN from KO mice showed a significantly increased proportion of CD8+ T cells compared to WT mice. At day 38 p.i. of cells a reduced tumour weight was evident in KO mice. This was accompanied by a decreased proportion of CD4+CD25+FoxP3+ regulatory T cells in TDLN of KO compared to WT mice. Tumour-bearing KO mice showed a better survival compared to WT mice. CONCLUSIONS: H4R-mediated mechanisms may modulate the immune tumour microenvironment, promoting an immunosuppressive milieu. Results suggest that H4R could be explored as an immunotherapeutic target with potential benefit in combination with immunotherapy. Further preclinical and clinical studies are necessary to confirm this hypothesis.
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Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Receptores Histamínicos H4/deficiência , Receptores Histamínicos H4/imunologia , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Modelos Animais de Doenças , Feminino , Histamina/imunologia , Subunidade alfa de Receptor de Interleucina-2/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Linfócitos T Reguladores/metabolismo , Microambiente Tumoral/imunologiaRESUMO
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).
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Animais , Camundongos , Anisakis , Linfócitos T Reguladores , Antígenos/metabolismo , Medula Óssea , Células Dendríticas , Fatores de Transcrição Forkhead , Subunidade alfa de Receptor de Interleucina-2 , Larva , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
T regulatory (Treg) cells have a major role in the maintenance of immune tolerance against self and foreign antigens through the control of harmful inflammation. Treg cells exert immunosuppressive function by several mechanisms, which can be distinguished as contact dependent or independent. Recently, the secretion of extracellular vesicles (EVs) by Treg cells has been reported as a novel suppressive mechanism capable of modulating immunity in a cell-contact independent and targeted manner, which has been identified in different pathologic scenarios. EVs are cell-derived membranous structures involved in physiologic and pathologic processes through protein, lipid, and genetic material exchange, which allow intercellular communication. In this review, we revise and discuss current knowledge on Treg cells-mediated immune tolerance giving special attention to the production and release of EVs. Multiple studies support that Treg cells-derived EVs represent a refined intercellular exchange device with the capacity of modulating immune responses, thus creating a tolerogenic microenvironment in a cell-free manner. The mechanisms proposed encompass miRNAs-induced gene silencing, the action of surface proteins and the transmission of enzymes. These observations gain relevance by the fact that Treg cells are susceptible to converting into effector T cells after exposition to inflammatory environments. Yet, in contrast to their cells of origin, EVs are unlikely to be modified under inflammatory conditions, highlighting the advantage of their use. Moreover, we speculate in the possibility that Treg cells may contribute to infectious tolerance via vesicle secretion, intervening with CD4+ T cells differentiation and/or stability.
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Vesículas Extracelulares/imunologia , Tolerância Imunológica/imunologia , Linfócitos T Reguladores/imunologia , Animais , Subpopulações de Linfócitos B/imunologia , Microambiente Celular , Fatores de Transcrição Forkhead/fisiologia , Inativação Gênica , Humanos , Proteínas de Checkpoint Imunológico/fisiologia , Tolerância Imunológica/genética , Imunoterapia , Inflamação/imunologia , Linfocinas/metabolismo , Camundongos , MicroRNAs/genética , Modelos Imunológicos , Receptores Imunológicos/fisiologiaRESUMO
Immunotherapy as an approach for cancer treatment is clinically promising. CD73, which is the enzyme that produces extracellular adenosine, favors cancer progression and protects the tumor from immune surveillance. While CD73 has recently been demonstrated to be a potential target for glioma treatment, its role in regulating the inflammatory tumor microenvironment has not yet been investigated. Thus, this study explores the immunotherapeutic value of the CD73 blockade in glioblastoma. The immuno-therapeutic value of the CD73 blockade was evaluated in vivo in immunocompetent pre-clinical glioblastoma model. As such, glioblastoma-bearing rats were nasally treated for 15 days with a siRNA CD73-loaded cationic-nanoemulsion (NE-siRNA CD73R). Apoptosis was determined by flow cytometry using Annexin-V staining and cell proliferation was analyzed by Ki67 expression by immunohistochemistry. The frequencies of the CD4+, CD8+, and CD4+CD25highCD39+ (Treg) T lymphocytes; CD11b+CD45high macrophages; CD11b+CD45low-microglia; and CD206+-M2-like phenotypes, along with expression levels of CD39 and CD73 in tumor and tumor-associated immune cells, were determined using flow cytometry, while inflammatory markers associated with tumor progression were evaluated using RT-qPCR. The CD73 blockade by NE-siRNA CD73 was found to induce tumor cell apoptosis. Meanwhile, the population of Tregs, microglia, and macrophages was significantly reduced in the tumor microenvironment, though IL-6, CCL17, and CCL22 increased. The treatment selectively decreased CD73 expression in the GB cells as well as in the tumor-associated-macrophages/microglia. This study indicates that CD73 knockdown using a nanotechnological approach to perform nasal delivery of siRNA-CD73 to CNS can potentially regulate the glioblastoma immune microenvironment and delay tumor growth by inducing apoptosis.
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5'-Nucleotidase/antagonistas & inibidores , 5'-Nucleotidase/imunologia , Proliferação de Células/fisiologia , Glioblastoma/imunologia , Glioblastoma/metabolismo , Glioma/imunologia , Glioma/metabolismo , Adenosina/imunologia , Adenosina/metabolismo , Animais , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral , Imuno-Histoquímica/métodos , Imunoterapia/métodos , Macrófagos/imunologia , Macrófagos/metabolismo , Microglia/imunologia , Microglia/metabolismo , RatosRESUMO
Mesenchymal stem cells (MSCs) have fueled ample translation for the treatment of immune-mediated diseases. They exert immunoregulatory and tissue-restoring effects. MSC-mediated transfer of mitochondria (MitoT) has been demonstrated to rescue target organs from tissue damage, yet the mechanism remains to be fully resolved. Therefore, we explored the effect of MitoT on lymphoid cells. Here, we describe dose-dependent MitoT from mitochondria-labeled MSCs mainly to CD4+ T cells, rather than CD8+ T cells or CD19+ B cells. Artificial transfer of isolated MSC-derived mitochondria increases the expression of mRNA transcripts involved in T-cell activation and T regulatory cell differentiation including FOXP3, IL2RA, CTLA4, and TGFß1, leading to an increase in a highly suppressive CD25+ FoxP3+ population. In a GVHD mouse model, transplantation of MitoT-induced human T cells leads to significant improvement in survival and reduction in tissue damage and organ T CD4+ , CD8+ , and IFN-γ+ expressing cell infiltration. These findings point to a unique CD4+ T-cell reprogramming mechanism with pre-clinical proof-of-concept data that pave the way for the exploration of organelle-based therapies in immune diseases.
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Células-Tronco Mesenquimais , Linfócitos T CD8-Positivos , Diferenciação Celular , Células-Tronco Mesenquimais/metabolismo , Mitocôndrias , Linfócitos T ReguladoresRESUMO
Knowledge of the role of Tregs in the immunopathogenesis of the different clinical outcomes within the leprosy spectrum remains limited due to the lack of studies directly assessing their suppression capacity. We thus tested a protocol to expand Tregs from the peripheral blood of patients across the leprosy spectrum and analyzed their suppressive capacity in autologous TCD4+ responses. Results of these pilot assays show that Tregs can be expanded and exert suppressive capacity, but also that their rate of expansion and suppressive capacity are influenced by the patient's clinical classification, suggesting that they possibly retain some in vivo characteristics.
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Hanseníase/imunologia , Linfócitos T Reguladores/imunologia , Proliferação de Células , Humanos , Tolerância Imunológica , Hanseníase/sangue , Hanseníase/classificação , Mycobacterium lepraemurium , Projetos PilotoRESUMO
BACKGROUND: Disease-tolerance mechanisms limit infection severity by preventing tissue damage; however, the underlying mechanisms in human malaria are still unclear. Tryptophan (TRP), an essential amino acid, is catabolized into tolerogenic metabolites, kynurenines (KYN), by indoleamine 2,3-dioxygenase 1 (IDO1), which can induce Foxp3+ T regulatory cells (Tregs). In this study, we evaluated the relationship of these metabolites with Treg-mediated tolerance induction in acute malaria infections. METHODS: We performed a cross-sectional study that evaluated asymptomatic, symptomatic malaria patients and endemic control patient groups. We assessed plasmatic concentration of cytokines by ELISA. Plasmatic TRP and KYN levels were measured by HPLC. Peripheral T regulatory cells were measured and phenotyped by flow cytometry. RESULTS: The KYN/TRP ratio was significantly elevated in asymptomatic and symptomatic Plasmodium infection, compared to healthy controls. Also, Th1 and Th2 cytokines were elevated in the acute phase of malaria disease. IFN-γ increase in acute phase was positively correlated with the KYN/TRP ratio and KYN elevation was positively correlated with the increase of peripheral FoxP3+ T regulatory cells. CONCLUSIONS: Additional studies are needed not only to identify innate mechanisms that increase tryptophan catabolism but also the role of Tregs in controlling malaria-induced pathology and malaria tolerance by the host.
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Cinurenina/sangue , Malária Vivax/imunologia , Plasmodium vivax/fisiologia , Linfócitos T Reguladores/imunologia , Adulto , Estudos Transversais , Feminino , Humanos , Tolerância Imunológica , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interferon gama/imunologia , Cinurenina/metabolismo , Masculino , Projetos Piloto , Triptofano/análise , Triptofano/metabolismoRESUMO
This study aimed to investigate the impact of a 16-week dance-based aerobic exercise program on lymphocyte function in healthy and type 2 diabetes mellitus (T2DM) women. We enrolled 23 women: 11 with T2DM and 12 non-diabetic controls. Initially, we performed anthropometry and body composition measurements, afterwards, plasma levels of C-reactive protein, lipids, and glucose were determined. We used flow cytometry to measure the CD25 and CD28 expression in circulating lymphocytes, T-regulatory (Treg) cell percentage, lymphocyte proliferation, and cytokines released by cultured lymphocytes. The T2DM group had a lower proportion of CD28+ cells and a higher percentage of Treg lymphocytes and proliferative capacity at the baseline compared with the control group. After 16 weeks of the program, differences in lymphocytes between the T2DM and the control groups disappeared. The dance program promoted IL-10 increase in both groups. We found decreased IL-4, IL-2, and IL-6 secretion in lymphocytes from the control group and increased IL-17 secretion and IL-10/IL-17 ratio in the T2DM group after the program. The program promoted marked changes in lymphocytes in diabetic women, leading to a balance between the different profiles.
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OBJECTIVE: The aim of this study was to evaluate the association between rs3761548 FOXP3 (-3279 C > A) variant and multiple sclerosis (MS), disability, disability progression, as well as transforming growth factor (TGF)-ß1 and interleukin (IL)-10 plasma levels in MS patients. METHODS AND SUBJECTS: The study included 170 MS patients and 182 controls. Disability was evaluated using Expanded Disability Status Scale (EDSS) and categorized as mild (EDSS ≤ 3) and moderate/high (EDSS > 3). Disability progression was evaluated using Multiple Sclerosis Severity Score (MSSS). The rs3761548 variant was determined with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Plasma levels of TGF-ß1 and IL-10 were determined using immunofluorimetric assay. RESULTS: CA and AA genotypes were associated with MS [odds ratio (OR) 2.03, 95% confidence interval (CI) 1.66-3.53, p = 0.012; OR 8.19, 95% CI 3.04-22.07, p < 0.001, respectively). With the dominant model, the CA + AA genotypes were associated with MS (OR 2.57, 95% CI 1.50-4.37, p < 0.001). In the recessive model, the AA genotype was also associated with MS (OR 5.38, 95% CI 2.12-13.64, p < 0.001). After adjustment by age, ethnicity, BMI and smoking, all these results remained significant, as well as female patients carrying the CA + AA genotypes showed higher TGF-ß1 than those carrying the CC genotype (OR 1.35, 95% CI 1.001-1.054, p = 0.043). No association was observed between the genotypes and disability, disability progression and IL-10 levels. CONCLUSION: These results suggest that the A allele of FOXP3 -3279 C > A variant may exert a role in the T regulatory cell function, which could be one of the factors involved in the susceptibility for MS in females.