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1.
Pediatr Res ; 94(5): 1789-1796, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37344544

RESUMO

BACKGROUND: Despite multifactorial pathogenesis, dysregulation of inflammatory immune response may play a crucial role in necrotizing enterocolitis (NEC). Regulatory T cells (Tregs) are involved in immune tolerance early in life. We aimed to investigate the predicting role of Tregs in developing NEC in neonates at high risk. METHODS: We studied six newborns with a diagnosis of NEC (cases) in comparison with 52 controls (without NEC). We further classified controls as neonates with feeding intolerance (FI) and neonates without it (FeedTol). The rate of female and male neonates (sex defined as a biological attribute) was similar. We analyzed the blood frequency of Tregs (not overall numbers) at three time points: 0-3 (T0), 7-10 (T1), and 27-30 (T2) days after birth by flow cytometry. Neonates' sex was defined based on the inspection of external genitalia at birth. RESULTS: We observed, at T0, a significantly lower frequency of Tregs in NEC cases (p < 0.001) compared with both FI (p < 0.01) and FeedTol controls (p < 0.01). Multivariate analysis reported that the occurrence of NEC was independently influenced by Treg frequency at birth (ß 2.98; p = 0.039). CONCLUSION: Tregs frequency and features in the peripheral blood of preterm neonates, early in life, may contribute to identifying neonates at high risk of developing NEC. IMPACT: Regulatory T cells may play a pivotal role in regulating the immune response in early life. Reduction of Tregs in early life could predispose preterm newborns to necrotizing enterocolitis. Early markers of necrotizing enterocolitis are still lacking. We demonstrated a predicting role of assessment of regulatory T cells in the diagnosis of this gastrointestinal emergency. Early identification of newborns at high risk of necrotizing enterocolitis through measurement of regulatory T cells may guide clinicians in the management of preterm newborns in order to reduce the development of this severe condition.


Assuntos
Enterocolite Necrosante , Doenças Fetais , Doenças do Recém-Nascido , Recém-Nascido , Masculino , Humanos , Feminino , Enterocolite Necrosante/diagnóstico , Enterocolite Necrosante/epidemiologia , Recém-Nascido Prematuro , Linfócitos T Reguladores
2.
Clin Exp Immunol ; 208(2): 181-192, 2022 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-35020862

RESUMO

Metabolic inflammation, defined as a chronic low-grade inflammation, is implicated in numerous metabolic diseases. In recent years, the role of regulatory T cells (Tregs) as key controllers of metabolic inflammation has emerged, but our comprehension on how different metabolic pathways influence Treg functions needs a deeper understanding. Here we focus on how circulating and intracellular lipid metabolism, in particular cholesterol metabolism, regulates Treg homeostasis, expansion, and functions. Cholesterol is carried through the bloodstream by circulating lipoproteins (chylomicrons, very low-density lipoproteins, low-density lipoproteins). Tregs are equipped with a wide array of metabolic sensors able to perceive and respond to changes in the lipid environment through the activation of different intracellular pathways thus conferring to these cells a crucial metabolic and functional plasticity. Nevertheless, altered cholesterol transport, as observed in genetic dyslipidemias and atherosclerosis, impairs Treg proliferation and function through defective cellular metabolism. The intracellular pathway devoted to the cholesterol synthesis is the mevalonate pathway and several studies have shown that this pathway is essential for Treg stability and suppressive activity. High cholesterol concentrations in the extracellular environment may induce massive accumulation of cholesterol inside the cell thus impairing nutrients sensors and inhibiting the mevalonate pathway. This review summarizes the current knowledge regarding the role of circulating and cellular cholesterol metabolism in the regulation of Treg metabolism and functions. In particular, we will discuss how different pathological conditions affecting cholesterol transport may affect cellular metabolism in Tregs.


Assuntos
Metabolismo dos Lipídeos , Linfócitos T Reguladores , Colesterol/metabolismo , Humanos , Inflamação/metabolismo , Ácido Mevalônico/metabolismo , Linfócitos T Reguladores/metabolismo
3.
Liver Int ; 41(3): 470-481, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33159402

RESUMO

BACKGROUND & AIMS: During chronic viral infections, the apoptosis of activated T cell elicits a CD8+ T cell response directed to those cryptic epitopes that emerge from caspase-cleaved structural proteins. Such response directed to apoptosis-associated epitopes (AEs) contributes to the amplification of immunopathology. METHODS: Here, we have analysed through flow cytometry AE-specific CD8+ T cells in patients with chronic hepatitis B virus (HBV) infection, naïve-to-treatment or undergoing nucleos(t)ide-analogue (NUC) therapy. RESULTS: We found that AE-specific CD8+ T cell frequencies were significantly increased only in those NUC-treated patients who also presented advanced hepatic fibrosis. Regulatory T cells were also expanded in those patients, and AE-specific, but not HBV-specific, CD8+ T cell frequency positively correlated with Treg percentages. Through multiparameter flow cytometry, multidimensionality reduction and unsupervised clustering analysis, we could identify novel subpopulations among effector memory (em) and emCD45RA+ T cell (Tem and Temra) subsets. CD8+ T cells with distinct specificities differentially populated the subpopulation map: while HBV-specific were mostly contained in the Tem subset, AE-specific CD8+ T cells encompassed naïve, as well as T central memory, Tem and Temra cells. CONCLUSION: All together, these findings indicate a link between AE-specific CD8+ T cells and advanced liver fibrosis in patients with chronic HBV infection, and suggest that virus-specific and AE-specific CD8+ T cells exhibit distinct differentiation states and contribute in distinct ways to immunopathology.


Assuntos
Linfócitos T CD8-Positivos , Hepatite B Crônica , Apoptose , Linfócitos T CD8-Positivos/imunologia , Epitopos , Fibrose , Vírus da Hepatite B , Hepatite B Crônica/patologia , Humanos
4.
Proc Natl Acad Sci U S A ; 115(28): E6546-E6555, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29941600

RESUMO

The tumor microenvironment restrains conventional T cell (Tconv) activation while facilitating the expansion of Tregs. Here we showed that Tregs' advantage in the tumor milieu relies on supplemental energetic routes involving lipid metabolism. In murine models, tumor-infiltrating Tregs displayed intracellular lipid accumulation, which was attributable to an increased rate of fatty acid (FA) synthesis. Since the relative advantage in glucose uptake may fuel FA synthesis in intratumoral Tregs, we demonstrated that both glycolytic and oxidative metabolism contribute to Tregs' expansion. We corroborated our data in human tumors showing that Tregs displayed a gene signature oriented toward glycolysis and lipid synthesis. Our data support a model in which signals from the tumor microenvironment induce a circuitry of glycolysis, FA synthesis, and oxidation that confers a preferential proliferative advantage to Tregs, whose targeting might represent a strategy for cancer treatment.


Assuntos
Ácidos Graxos/imunologia , Glicólise/imunologia , Neoplasias Experimentais/imunologia , Linfócitos T Reguladores/imunologia , Microambiente Tumoral/imunologia , Animais , Linhagem Celular Tumoral , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/imunologia , Ácidos Graxos/genética , Humanos , Camundongos , Camundongos Transgênicos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Oxirredução , Linfócitos T Reguladores/patologia , Microambiente Tumoral/genética
5.
Int J Mol Sci ; 22(8)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918901

RESUMO

T cells undergo activation and differentiation programs along a continuum of states that can be tracked through flow cytometry using a combination of surface and intracellular markers. Such dynamic behavior is the result of transcriptional and post-transcriptional events, initiated and sustained by the activation of specific transcription factors and by epigenetic remodeling. These signaling pathways are tightly integrated with metabolic routes in a bidirectional manner: on the one hand, T cell receptors and costimulatory molecules activate metabolic reprogramming; on the other hand, metabolites modify T cell transcriptional programs and functions. Flow cytometry represents an invaluable tool to analyze the integration of phenotypical, functional, metabolic and transcriptional features, at the single cell level in heterogeneous T cell populations, and from complex microenvironments, with potential clinical application in monitoring the efficacy of cancer immunotherapy. Here, we review the most recent advances in flow cytometry-based analysis of gene expression, in combination with indicators of mitochondrial activity, with the aim of revealing and characterizing major metabolic pathways in T cells.


Assuntos
Metabolismo Energético , Citometria de Fluxo , RNA/genética , Linfócitos T/metabolismo , Animais , Biomarcadores , Citometria de Fluxo/métodos , Expressão Gênica , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/imunologia
6.
Int J Cancer ; 147(9): 2597-2610, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483858

RESUMO

In our study, we investigated the role of CD39 on tumor-infiltrating CD8+ T lymphocytes (CD8+ TILs) in colorectal, head and neck and pancreatic cancers. Partially confirming recent observations correlating the CD39 expression with T-cell exhaustion, we demonstrated a divergent functional activity in CD39+ CD8+ TILs. On the one hand, CD39+ CD8+ TILs (as compared to their CD39- counterparts) produced significantly lower IFN-γ and IL-2 amounts, expressed higher PD-1, and inversely correlated with perforin and granzyme B expression. On the other, they displayed a significantly higher proliferative capacity ex vivo that was inversely correlated with the PD-1 expression. Therefore, CD39+ CD8+ TILs, including those co-expressing the CD103 (a marker of T resident memory [TRM] cells), were defined as partially dysfunctional T cells that correlate with tumor patients with initial progression stages. Interestingly, our results identified for the first time a single nucleotide polymorphism (SNP rs10748643 A>G), as a genetic factor associated with CD39 expression in CD8+ TILs. Finally, we demonstrated that compounds inhibiting CD39-related ATPases improved CD39+ CD8+ T-cell effector function ex vivo, and that CD39+ CD8+ TILs displayed effective suppression function in vitro. Overall these data suggest that the SNP analysis may represent a suitable predictor of CD39+ CD8+ T-cell expression in cancer patients, and propose the modulation of CD39 as a new strategy to restore partially exhausted CD8+ TILs.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apirase/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Neoplasias/imunologia , Linfócitos T Citotóxicos/imunologia , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apirase/antagonistas & inibidores , Apirase/genética , Células Cultivadas , Feminino , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Nivolumabe/farmacologia , Nivolumabe/uso terapêutico , Polimorfismo de Nucleotídeo Único , Cultura Primária de Células , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/metabolismo
7.
Hepatology ; 60(5): 1494-507, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24756990

RESUMO

UNLABELLED: Regulatory T cells (Tregs) can be considered as a mixed population of distinct subsets, endowed with a diverse extent and quality of adaptation to microenvironmental signals. Here, we uncovered an opposite distribution of Treg expansion, phenotype, and plasticity in different microenvironments in the same organ (liver) derived from patients with chronic hepatitis C: On the one side, cirrhotic and tumor fragments were moderately and highly infiltrated by Tregs, respectively, expressing OX40 and a T-bethigh IFN-γ- "T-helper (Th)1-suppressing" phenotype; on the other side, noncirrhotic liver specimens contained low frequencies of Tregs that expressed low levels of OX40 and highly produced interferon-gamma (IFN-γ; T-bet+IFN-γ+), thus becoming "Th1-like" cells. OX40-expressing and Th1-suppressing Tregs were enriched in the Helios-positive subset, carrying highly demethylated Treg cell-specific demethylated region that configures committed Tregs stably expressing forkhead box protein 3. OX40 ligand, mostly expressed by M2-like monocytes and macrophages, boosted OX40+ Treg proliferation and antagonized the differentiation of Th1-like Tregs. However, this signal is counteracted in noncirrhotic liver tissue (showing various levels of inflammation) by high availability of interleukin-12 and IFN-γ, ultimately leading to complete, full Th1-like Treg differentiation. CONCLUSION: Our data demonstrate that Tregs can finely adapt, or even subvert, their classical inhibitory machinery in distinct microenvironments within the same organ.


Assuntos
Carcinoma Hepatocelular/imunologia , Hepatite C/imunologia , Cirrose Hepática/imunologia , Neoplasias Hepáticas/imunologia , Receptores OX40/metabolismo , Linfócitos T Reguladores/fisiologia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/virologia , Feminino , Hepatite C/complicações , Humanos , Fator de Transcrição Ikaros/metabolismo , Interleucina-12/metabolismo , Cirrose Hepática/virologia , Neoplasias Hepáticas/virologia , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Ligante OX40/metabolismo , Fenótipo , Regulação para Cima
8.
Immunol Lett ; 266: 106839, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38309375

RESUMO

The X-linked chronic granulomatous disease (X-CGD), a rare genetic disease characterised by recurrent infections, is caused by mutations of NOX2. Significant proportions of X-CGD patients display signs of immune dysregulation. Regulatory T cells (Tregs) are CD4+T lymphocytes that expand in active inflammation and prevent autoimmune disorders. Here we asked whether X-CGD is associated to Treg dysfunctions in adult patients. To this aim, the frequency of Tregs was analysed through intracellular flow cytometry in a cohort of adult X-CGD patients, carriers and controls. We found that Tregs were significantly expanded and activated in blood of adult X-CGD patients, and this was associated with activation of conventional CD4+T cells (Tconvs). T cell activation was characterised by accumulation of intracellular ROS, not derived from NOX2 but likely produced by cellular metabolism. The higher TNF production by Tconvs in X-CGD patients might contribute to the expansion of Tregs through the TNFR2 receptor. In summary, our data indicate that Tregs expand in adult X-CGD in response to immune activation, and that the increase of NOX2-independent ROS content is a feature of activated T cells.


Assuntos
Doença Granulomatosa Crônica , Adulto , Humanos , Doença Granulomatosa Crônica/genética , Doença Granulomatosa Crônica/metabolismo , Linfócitos T Reguladores , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Mutação
9.
JCI Insight ; 9(15)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954474

RESUMO

Besides suppressing immune responses, regulatory T cells (Tregs) maintain tissue homeostasis and control systemic metabolism. Whether iron is involved in Treg-mediated tolerance is completely unknown. Here, we showed that the transferrin receptor CD71 was upregulated on activated Tregs infiltrating human liver cancer. Mice with a Treg-restricted CD71 deficiency spontaneously developed a scurfy-like disease, caused by impaired perinatal Treg expansion. CD71-null Tregs displayed decreased proliferation and tissue-Treg signature loss. In perinatal life, CD71 deficiency in Tregs triggered hepatic iron overload response, characterized by increased hepcidin transcription and iron accumulation in macrophages. Lower bacterial diversity, and reduction of beneficial species, were detected in the fecal microbiota of CD71 conditional knockout neonates. Our findings indicate that CD71-mediated iron absorption is required for Treg perinatal expansion and is related to systemic iron homeostasis and bacterial gut colonization. Therefore, we hypothesize that Tregs establish nutritional tolerance through competition for iron during bacterial colonization after birth.


Assuntos
Antígenos CD , Ferro , Receptores da Transferrina , Linfócitos T Reguladores , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Receptores da Transferrina/metabolismo , Animais , Ferro/metabolismo , Camundongos , Humanos , Antígenos CD/metabolismo , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Camundongos Knockout , Feminino , Microbioma Gastrointestinal/imunologia , Masculino , Fígado/metabolismo , Fígado/imunologia , Homeostase
11.
Front Immunol ; 13: 932240, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35958600

RESUMO

Baricitinib is a Janus kinase (JAK) 1 and 2 inhibitor approved for treating rheumatoid arthritis (RA). The JAK/STAT system is essential in the intracellular signaling of different cytokines and in the activation process of the monocyte lineage. This study verifies the effects of baricitinib on STAT phosphorylation in monocytes of RA patients and evaluates the correlation between STAT phosphorylation and response to therapy. We evaluated the disease activity of patients (DAS28CRP) at baseline (T0) and after 4 and 12 weeks (T1-T3) of treatment with baricitinib, dividing them into responders (n = 7) and non-responders (n = 7) based on the reduction of DAS28CRP between T0 and T1 of at least 1.2 points. Through flow cytometry, STAT1 phosphorylation was analyzed at T0/T1/T3 in monocytes, at basal conditions and after IL2, IFNα, and IL6 stimulation. We showed that monocyte frequency decreased from T0 to T1 only in responders. Regarding the phosphorylation of STAT1, we observed a tendency for higher basal pSTAT1 in monocytes of non-responder patients and, after 4 weeks, a significant reduction of cytokine-induced pSTAT1 in monocytes of responders compared with non-responders. The single IFNα stimulation only partially recapitulated the differences in STAT1 phosphorylation between the two patient subgroups. Finally, responders showed an increased IFN signature at baseline compared with non-responders. These results may suggest that monocyte frequency and STAT1 phosphorylation in circulating monocytes could represent early markers of response to baricitinib therapy.


Assuntos
Artrite Reumatoide , Azetidinas , Artrite Reumatoide/tratamento farmacológico , Azetidinas/farmacologia , Azetidinas/uso terapêutico , Humanos , Interferon-alfa , Monócitos , Fosforilação , Purinas , Pirazóis , Fator de Transcrição STAT1 , Sulfonamidas
12.
Atherosclerosis ; 362: 38-46, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36253169

RESUMO

BACKGROUND AND AIMS: Angiopoietin-like 3 (ANGPTL3) regulates lipid and glucose metabolism. Loss-of-function mutations in its gene, leading to ANGPTL3 deficiency, cause in humans the familial combined hypolipidemia type 2 (FHBL2) phenotype, characterized by very low concentrations of circulating lipoproteins and reduced risk of atherosclerotic cardiovascular disease. Whether this condition is accompanied by immune dysfunctions is unknown. Regulatory T cells (Tregs) are CD4 T lymphocytes endowed with immune suppressive and atheroprotective functions and sensitive to metabolic signals. By investigating FHBL2, we explored the hypothesis that Tregs expand in response to extreme hypolipidemia, through a modulation of the Treg-intrinsic lipid metabolism. METHODS: Treg frequency, phenotype, and intracellular lipid content were assessed ex vivo from FHBL2 subjects and age- and sex-matched controls, through multiparameter flow cytometry. The response of CD4 T cells from healthy controls to marked hypolipidemia was tested in vitro in low-lipid culture conditions. RESULTS: The ex vivo analysis revealed that FHBL2 subjects showed higher percentages of Tregs with a phenotype undistinguishable from controls and with a lower lipid content, which directly correlated with the concentrations of circulating lipoproteins. In vitro, lipid restriction induced the upregulation of genes of the mevalonate pathway, including those involved in isoprenoid biosynthesis, and concurrently increased the expression of the Treg markers FOXP3 and Helios. The latter event was found to be prenylation-dependent, and likely related to increased IL-2 production and signaling. CONCLUSIONS: Our study demonstrates that FHBL2 is characterized by high Treg frequencies, a feature which may concur to the reduced atherosclerotic risk in this condition. Mechanistically, hypolipidemia may directly favor Treg expansion, through the induction of the mevalonate pathway and the prenylation of key signaling proteins.


Assuntos
Doenças Metabólicas , Linfócitos T Reguladores , Humanos , Linfócitos T Reguladores/metabolismo , Proteínas Semelhantes a Angiopoietina/genética , Angiopoietinas/genética , Angiopoietinas/metabolismo , Ácido Mevalônico , Proteína 3 Semelhante a Angiopoietina , Lipoproteínas , Fatores de Transcrição Forkhead/genética
13.
Cell Death Dis ; 12(11): 1026, 2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34716313

RESUMO

The autoimmune immunopathology occurring in multiple sclerosis (MS) is sustained by myelin-specific and -nonspecific CD8+ T cells. We have previously shown that, in MS, activated T cells undergoing apoptosis induce a CD8+ T cell response directed against antigens that are unveiled during the apoptotic process, namely caspase-cleaved structural proteins such as non-muscle myosin and vimentin. Here, we have explored in vivo the development and the function of the immune responses to cryptic apoptosis-associated epitopes (AEs) in a well-established mouse model of MS, experimental autoimmune encephalomyelitis (EAE), through a combination of immunization approaches, multiparametric flow cytometry, and functional assays. First, we confirmed that this model recapitulated the main findings observed in MS patients, namely that apoptotic T cells and effector/memory AE-specific CD8+ T cells accumulate in the central nervous system of mice with EAE, positively correlating with disease severity. Interestingly, we found that AE-specific CD8+ T cells were present also in the lymphoid organs of unprimed mice, proliferated under peptide stimulation in vitro, but failed to respond to peptide immunization in vivo, suggesting a physiological control of this response. However, when mice were immunized with AEs along with EAE induction, AE-specific CD8+ T cells with an effector/memory phenotype accumulated in the central nervous system, and the disease severity was exacerbated. In conclusion, we demonstrate that AE-specific autoimmunity may contribute to immunopathology in neuroinflammation.


Assuntos
Apoptose/imunologia , Linfócitos T CD8-Positivos/imunologia , Encefalomielite Autoimune Experimental/imunologia , Epitopos de Linfócito T/imunologia , Ativação Linfocitária/imunologia , Esclerose Múltipla/imunologia , Animais , Sistema Nervoso Central/imunologia , Feminino , Imunização/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Glicoproteína Mielina-Oligodendrócito/administração & dosagem , Ovalbumina/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Fenótipo , Índice de Gravidade de Doença
14.
Methods Enzymol ; 632: 283-294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32000901

RESUMO

Regulatory T cells (Tregs), expressing the transcription factor Foxp3, are defined as immunosuppressive cells able to modulate a variety of immune cells in order to avoid unwanted and excessive immune responses; however, in the tumor context, Treg function contribute to inhibit immune surveillance, thus promoting cancer progression. In tumor microenvironment, where the availability of metabolic resources is strongly limited, Tregs are expanded and may exploit different metabolic routes to achieve a metabolic advantage, prevailing over effector cells. In this context an important role of lipid metabolism has been described thanks to the possibility to evaluate the intracellular lipid content selectively in tumor-infiltrating Tregs (TUM-Tregs). Taking into account the heterogeneous and complex build of tumor mass, we set-up a combined protocol that optimizes tumor-infiltrating lymphocytes (TIL) extraction from the tissue through a Percoll density gradient, and assesses ex vivo the lipid load in whole TUM-Treg population, evaluating by flow cytometry the incorporation of an intensely fluorescent lipophilic fluorophore able to specifically stain neutral lipids. This method provides an important advantage compared to the traditional technique based on microscopy, whose lipid level evaluation is limited to a tissue section, and hence may not be representative of the entire population.


Assuntos
Citometria de Fluxo/métodos , Lipídeos/análise , Linfócitos do Interstício Tumoral/química , Animais , Compostos de Boro/análise , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral , Corantes Fluorescentes/análise , Metabolismo dos Lipídeos , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/química , Neoplasias/metabolismo , Neoplasias/patologia
15.
Front Immunol ; 11: 350, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231663

RESUMO

Atherosclerosis is a progressive vascular disease representing the primary cause of morbidity and mortality in developed countries. Formerly, atherosclerosis was considered as a mere passive accumulation of lipids in blood vessels. However, it is now clear that atherosclerosis is a complex and multifactorial disease, in which the involvement of immune cells and inflammation play a key role. A variety of studies have shown that autophagy-a cellular catalytic mechanism able to remove injured cytoplasmic components in response to cellular stress-may be proatherogenic. So far, in this context, its role has been investigated in smooth muscle cells, macrophages, and endothelial cells, while the function of this catabolic protective process in lymphocyte functionality has been overlooked. The few studies carried out so far, however, suggested that autophagy modulation in lymphocyte subsets may be functionally related to plaque formation and development. Therefore, in this research, we aimed at better clarifying the role of lymphocyte subsets, mainly regulatory T cells (Tregs), in human atherosclerotic plaques and in animal models of atherosclerosis investigating the contribution of autophagy on immune cell homeostasis. Here, we investigate basal autophagy in a mouse model of atherosclerosis, apolipoprotein E (ApoE)-knockout (KO) mice, and we analyze the role of autophagy in driving Tregs polarization. We observed defective maturation of Tregs from ApoE-KO mice in response to tumor growth factor-ß (TGFß). TGFß is a well-known autophagy inducer, and Tregs maturation defects in ApoE-KO mice seem to be related to autophagy impairment. In this work, we propose that autophagy underlies Tregs maturation, advocating that the study of this process in atherosclerosis may open new therapeutic strategies.


Assuntos
Aterosclerose/imunologia , Autofagia/fisiologia , Linfócitos T Reguladores/citologia , Aldosterona/farmacologia , Animais , Apolipoproteínas E/fisiologia , Aterosclerose/fisiopatologia , Aterosclerose/terapia , Autofagia/efeitos dos fármacos , Diferenciação Celular , Polaridade Celular , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Placa Aterosclerótica/imunologia , Linfócitos T Reguladores/fisiologia , Fator de Crescimento Transformador beta/farmacologia
16.
Clin Transl Immunology ; 9(12): e1221, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33376595

RESUMO

OBJECTIVES: Type I interferons (IFNs) inhibit regulatory T-cell (Treg) expansion and activation, making them beneficial in antiviral responses, but detrimental in autoimmune diseases. Herein, we investigate the role of ISG15 in human Tregs in the context of refractoriness to type I IFN stimulation. METHODS: ISG15 expression and Treg dynamics were analysed in vitro and ex vivo from patients with chronic hepatitis C, with lupus and ISG15 deficiency. RESULTS: ISG15 is expressed at high levels in human Tregs, renders them refractory to the IFN-STAT1 signal, and protects them from IFN-driven contraction. In vitro, Tregs from healthy controls upregulate ISG15 upon activation to higher levels than conventional CD4 T cells, and ISG15-silenced Tregs are more susceptible to IFNα-induced contraction. In human ISG15 deficiency, patient Tregs display an elevated IFN signature relative to Tregs from healthy control. In vivo, in patients with chronic hepatitis C, 2 days after starting pegIFN/ribavirin therapy, a stronger ISG15 inducibility correlates with a milder Treg depletion. Ex vivo, in systemic lupus erythematosus patients, higher levels of ISG15 are associated to reduced STAT1 phosphorylation in response to IFNα, and also to increased frequencies of Tregs, characterising active disease. CONCLUSION: Our results reveal a Treg-intrinsic role of ISG15 in dictating their refractoriness to the IFN signal, thus preserving the Treg population under inflammatory conditions.

17.
Front Immunol ; 10: 1889, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507585

RESUMO

In the last decades, immunologists have started to consider intracellular metabolism in relation with the dynamics and functions of immune cells, especially when it became clear that microenvironmental alterations were associated with immune dysfunctions. Regulatory T cells (Tregs) are equipped with a variety of immunological and metabolic sensors, and encompass circulating as well as tissue-resident cells, being therefore particularly susceptible to microenvironmental cues. Moreover, Tregs undergo metabolic reprogramming over the course of an immune response, allowing the use of alternate substrates and engaging different metabolic pathways for energetic demands. The study of metabolic mechanisms supporting Treg dynamics has led to puzzling results, due to several limitations, including the heterogeneity of population in the same tissues and between different tissues, the difficulty in considering all the interconnected metabolic pathways during a cellular process, and the differences between in vitro and in vivo conditions. Therefore, Treg reliance on different metabolic routes (oxidation rather than glycolysis) has been a matter of controversy in recent years. Metabolic reprogramming and altered bioenergetics are now identified as hallmarks in cancer, and are employed by cancer cells to determine the availability of metabolites and molecules, thus affecting the fate of tumor-infiltrating immune cells. In particular, the tumor microenvironment forces a metabolic restriction and a plethora of synergistic intrinsic and extrinsic stresses, leading to an impaired anti-tumor immunity and favoring Treg generation, expansion, and suppressive function. This leads to the understanding that Tregs and conventional T cells have different capability to adapt to metabolic hurdles. Considering the role of Tregs in dictating the outcome of tumor-specific responses, it would be important to understand the specific Treg metabolic profile that provides an advantage at the tumor site, to finally identify new targets for therapy. In this review, we will report and discuss the major recent findings about the metabolic pathways required for Treg development, expansion, migration and functions, in relation to tissue-derived signals. We will focus on the adipose tissue and the liver, where Tregs are exposed to a variety of metabolites, and on the tumor microenvironment as the context where Tregs develop the ability to adapt to perturbations in nutrient accessibility.


Assuntos
Metabolismo Energético , Imunomodulação , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Adaptação Biológica/imunologia , Animais , Microambiente Celular/genética , Microambiente Celular/imunologia , Espaço Extracelular/metabolismo , Humanos , Ativação Linfocitária/imunologia , Redes e Vias Metabólicas , Neoplasias/etiologia , Neoplasias/metabolismo , Neoplasias/patologia , Transdução de Sinais , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
18.
Cancer Immunol Res ; 6(8): 953-964, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30018042

RESUMO

The Wnt/ß-catenin pathway regulates T-cell functions, including the repression of effector functions to the advantage of memory development via Tcf1. In a companion study, we demonstrate that, in human cancers, Wnt3a/ß-catenin signaling maintains tumor-infiltrating T cells in a partially exhausted status. Here, we have investigated the effects of Wnt3a neutralization in vivo in a mouse tumor model. Abundant Wnt3a was released, mostly by stromal cells, in the tumor microenvironment. We tested whether Wnt3a neutralization in vivo could rescue the effector capacity of tumor-infiltrating T cells, by administering an antibody to Wnt3a to tumor-bearing mice. This therapy restrained tumor growth and favored the expansion of tumor antigen-specific CD8+ effector memory T cells with increased expression of Tbet and IFNγ and reduced expression of Tcf1. However, the effect was not attributable to the interruption of T-cell-intrinsic ß-catenin signaling, because Wnt3a/ß-catenin activation correlated with enhanced, not reduced, T-cell effector functions both ex vivo and in vitro Adoptively transferred CD8+ T cells, not directly exposed to the anti-Wnt3a antibody but infiltrating previously Wnt3a-neutralized tumors, also showed improved functions. The rescue of T-cell response was thus secondary to T-cell-extrinsic changes that likely involved dendritic cells. Indeed, tumor-derived Wnt3a strongly suppressed dendritic cell maturation in vitro, and anti-Wnt3a treatment rescued dendritic cell activities in vivo Our results clarify the function of the Wnt3a/ß-catenin pathway in antitumor effector T cells and suggest that Wnt3a neutralization might be a promising immunotherapy for rescuing dendritic cell activities. Cancer Immunol Res; 6(8); 953-64. ©2018 AACR.


Assuntos
Adenocarcinoma/terapia , Neoplasias do Colo/terapia , Linfócitos do Interstício Tumoral/imunologia , Via de Sinalização Wnt/imunologia , Proteína Wnt3A/imunologia , Adenocarcinoma/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Células Dendríticas/imunologia , Humanos , Imunoterapia/métodos , Transfusão de Linfócitos/métodos , Masculino , Camundongos Endogâmicos C57BL , Células Estromais/imunologia , Proteína Wnt3A/antagonistas & inibidores , Proteína Wnt3A/biossíntese
19.
Cell Rep ; 25(11): 3059-3073.e10, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30540939

RESUMO

Mitochondria are key players in the regulation of T cell biology by dynamically responding to cell needs, but how these dynamics integrate in T cells is still poorly understood. We show here that the mitochondrial pro-fission protein Drp1 fosters migration and expansion of developing thymocytes both in vitro and in vivo. In addition, we find that Drp1 sustains in vitro clonal expansion and cMyc-dependent metabolic reprogramming upon activation, also regulating effector T cell numbers in vivo. Migration and extravasation defects are also exhibited in Drp1-deficient mature T cells, unveiling its crucial role in controlling both T cell recirculation in secondary lymphoid organs and accumulation at tumor sites. Moreover, the observed Drp1-dependent imbalance toward a memory-like phenotype favors T cell exhaustion in the tumor microenvironment. All of these findings support a crucial role for Drp1 in several processes during T cell development and in anti-tumor immune-surveillance.


Assuntos
Movimento Celular , Dinaminas/metabolismo , Vigilância Imunológica , Proteínas Proto-Oncogênicas c-myc/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia , Animais , Contagem de Células , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Homeostase , Ativação Linfocitária/imunologia , Tecido Linfoide/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos Knockout , Fenótipo , Receptores de Antígenos de Linfócitos T , Timócitos/citologia , Timócitos/metabolismo
20.
Front Immunol ; 8: 643, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28649243

RESUMO

Visceral adipose tissue (VAT) is a main site where metabolic and immunologic processes interplay to regulate, at local and systemic level, the inflammatory status and immune response. Obesity-associated inflammation and immune dysfunctions are inextricably linked to tumor but, in spite of intense efforts, the mechanisms underpinning this association remain elusive. In this report, we characterized the profile of VAT-associated and circulating innate lymphocyte and regulatory T (Treg) cell subsets underlying inflammatory conditions, such as obesity and colorectal cancer (CRC). Analysis of NK, NKT-like, γδ T, and Treg cell populations in VAT and blood of healthy lean subjects revealed that CD56hi NK and OX40+ Treg cells are more abundant in VAT with respect to blood. Conversely, CD56dim NK and total Treg cells are most present in the circulation, while γδ T lymphocytes are uniformly distributed in the two compartments. Interestingly, a reduced frequency of circulating activated Treg cells, and a concomitant preferential enrichment of OX40-expressing Treg cells in VAT, were selectively observed in obese (Ob) subjects, and directly correlated with body mass index. Likewise, CRC patients were characterized by a specific enrichment of VAT-associated NKT-like cells. In addition, Ob and CRC-affected individuals shared a significant reduction of the Vγ9Vδ2/γδ T cell ratio at systemic level. The alterations in the relative proportions of Treg and NKT-like cells in VAT were found to correlate with the content of pro- and anti-inflammatory polyunsaturated fatty acids (PUFA), respectively. Overall, these results provide evidence for distinct alterations of the immune cell repertoire in the periphery with respect to the VAT microenvironment that uniquely characterize or are shared by different inflammatory conditions, such as obesity and CRC, and suggest that VAT PUFA composition may represent one of the factors that contribute to shape the immune phenotypes.

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