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1.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(11): 961-966, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31878990

RESUMO

Objective To investigate the levels and function status of CD4+CD25-FOXP3+ T cells (CD25- Tregs) in the peripheral blood and synovial fluid from rheumatoid arthritis (RA) patients, and their relationships with disease activity. Methods The study enrolled 60 RA patients and 69 healthy controls (HCs). Flow cytometry was used to analyze the percentage and phenotype of CD25- Tregs, and the results were analyzed by Mann-Whitey U test and Spearman correlation. Results The percentage of circulating CD25- Tregs in CD4+ cells was compared between RA patients and HCs. However, the percentage of CD25- Tregs in RA synovial fluid was significantly higher than that in the peripheral blood of RA patients and HCs. When RA patients were grouped according to their disease activity or clinical indicators, such as rheumatoid factor (RF), anti-cyclic citrullinated peptides (CCP) antibody, anti-mutated citrullinated vimentin (MCV) antibody and anti-keratin antibody (AKA), circulating CD25- Tregs percentage was not significantly different among the groups, and had no correlation with the levels of erythrocyte sedimentation rate (ESR) and C reactive protein (CRP). The expression of CD39 in CD25- Tregs in RA synovial fluid was significantly lower than that in the peripheral blood of HCs. And CD73 and TGF-ß1 expression in CD25- Tregs in RA synovial fluid were significantly lower than those in the peripheral blood of both RA patients and HCs. However, there was no significant difference in the expression of CTLA4 and IL-10 in CD25- Tregs among the groups. Conclusion The percentage of CD25- Tregs increases in RA synovial fluid. And the expression of CD39, CD73 and TGF-ß1 decrease in CD25- Tregs, suggesting that its inhibitory function may be defective, resulting in local inflammation not being effectively controlled.


Assuntos
Artrite Reumatoide/imunologia , Líquido Sinovial/citologia , Linfócitos T Reguladores/imunologia , 5'-Nucleotidase/metabolismo , Apirase/metabolismo , Estudos de Casos e Controles , Fatores de Transcrição Forkhead/metabolismo , Proteínas Ligadas por GPI/metabolismo , Humanos , Fator de Crescimento Transformador beta1/metabolismo
2.
Curr Protein Pept Sci ; 20(9): 873-884, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31272352

RESUMO

ATP-diphosphohydrolases (EC 3.6.1.5), also known as ATPDases, NTPases, NTPDases, EATPases or apyrases, are enzymes that hydrolyze a variety of nucleoside tri- and diphosphates to their respective nucleosides, being their activities dependent on the presence of divalent cations, such as calcium and magnesium. Recently, ATP-diphosphohydrolases were identified on the surface of several parasites, such as Trypanosoma sp, Leishmania sp and Schistosoma sp. In parasites, the activity of ATPdiphosphohydrolases has been associated with the purine recuperation and/or as a protective mechanism against the host organism under conditions that involve ATP or ADP, such as immune responses and platelet activation. These proteins have been suggested as possible targets for the development of new antiparasitic drugs. In this review, we will comprehensively address the main aspects of the location and function of ATP-diphosphohydrolase in parasites. Also, we performed a detailed research in scientific database of recent developments in new natural and synthetic inhibitors of the ATPdiphosphohydrolases in parasites.


Assuntos
Trifosfato de Adenosina/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Parasitos/metabolismo , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Apirase/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Parasitos/efeitos dos fármacos
3.
Virchows Arch ; 475(3): 357-364, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31218404

RESUMO

Chronic intervillositis of unknown etiology (CIUE) is a rare placental lesion associated with infiltration of mononuclear inflammatory cells into the intervillous space, poor perinatal outcomes (intrauterine fetal demise or fetal growth restriction), and high rates of recurrence. CD39 is the ectonucleotidase that protects tissues from inflammatory stress and cell injury, which is localized on the surface of villi in normal placentas; however, its expression and role in CIUE are unknown. The aims of this retrospective study were to determine the expression of CD39 in CIUE and its significance in pregnancy outcomes. We compared the number of CD68- and CD3-positive cells, CD39 expression, and complement 4d (C4d) and fibrin deposition in placental tissues from patients with CIUE (n = 22) and gestational age-matched controls (n = 20), and between CIUE pregnancies with poor and good outcomes. The numbers of CD68- or CD3-positive cells were significantly higher (P < 0.0001), whereas CD39 expression on the surface of villi and endothelial cells of the stem villi was significantly lower in the CIUE group than that in controls (45% vs. 95%, P < 0.0001 and 77% vs. 96%, P < 0.001, respectively). C4d and fibrin deposition were also significantly increased in CIUE compared with those of controls. Furthermore, CD39 downregulation and the number of CD68 cells were strongly associated with poor pregnancy outcomes (P < 0.01 and P < 0.05, respectively), but other histological parameters (CD3, C4d, and fibrin) did not show this association. Our study suggests that CD39 downregulation is a useful marker of CIUE and is associated with poor pregnancy outcomes in patients with CIUE.


Assuntos
Apirase/metabolismo , Doenças Placentárias/patologia , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Apirase/fisiologia , Complexo CD3/análise , Vilosidades Coriônicas/patologia , Regulação para Baixo , Células Endoteliais/patologia , Feminino , Retardo do Crescimento Fetal/patologia , Humanos , Placenta/patologia , Doenças Placentárias/metabolismo , Gravidez , Resultado da Gravidez/epidemiologia , Recidiva , Estudos Retrospectivos
4.
Mediators Inflamm ; 2019: 4651627, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31205451

RESUMO

The development of cervical cancer (CeCa) is associated with high-risk human papilloma virus (HR-HPV) infections, mainly HPV-16, which is present in more than 50% of cases. The presence of immunosuppressive factors in the early stages of the disease is also strongly linked to CeCa progression. In this context, it is unknown whether ectonucleotidases CD39 and CD73, which are involved in the production of adenosine (Ado) that suppresses the specific antitumor immune response, are present in precursor lesions of CeCa. In this pilot study, we analyzed the presence of CD39 and CD73 and their capacity to generate Ado in 25 cervical samples from patients with grade 1 cervical intraepithelial neoplasms (CIN-1) and 25 samples from normal donors (NDs) free of HPV infection. Cells obtained from cervical samples of CIN-1 patients positive for HPV-16 showed higher CD39 and CD73 contents compared to samples obtained from CIN-1 patients negative for HPV-16 and NDs. Interestingly, solubilized cervical mucus from these patients also showed higher contents of soluble CD39 and CD73, which were associated with a greater capacity to produce Ado from the hydrolysis of adenosine triphosphate (ATP) and adenosine monophosphate (AMP). In addition, serum samples of these patients showed higher levels of TGF-ß than those of CIN-1 patients negative for HPV-16 and ND. These results suggest that persistent infection with HR-HPV, mostly HPV-16, in CIN-1 patients may promote the expression of CD39 and CD73 through the production of TGF-ß in precursor lesions to generate an immunosuppressive microenvironment and allow its progression to CeCa.


Assuntos
5'-Nucleotidase/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Neoplasia Intraepitelial Cervical/metabolismo , Neoplasia Intraepitelial Cervical/virologia , Infecções por Papillomavirus/enzimologia , Infecções por Papillomavirus/metabolismo , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/virologia , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Adolescente , Adulto , Estudos Transversais , Feminino , Papillomavirus Humano 16/patogenicidade , Humanos , Fator de Crescimento Transformador beta/metabolismo , Adulto Jovem
5.
J Immunol Res ; 2019: 1242979, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31198791

RESUMO

Cervical cancer is the second most frequent cancer in women in Mexico, and its development depends on the presence of human papillomaviruses in the uterine cervix. These oncogenic viruses transform cells where the control over cell cycle disappears, and the capacity to induce apoptosis is absent. On the other hand, some mutations confer to the transformed cells the ability to evade recognition by the immune system. The expression of markers of the immune system such as CD95, MICA/B, CD39, CD73, NKp30, NKp46, CD44, CD24, NKG2A, and CTLA-4 was analysed by flow cytometry on cervical cancer cells INBL (HPV 18, stage IVB), HeLa (HPV 18), CaSki (HPV 16), and C33A (HPV-). Our results showed the presence of atypical markers on cervical cancer cells; some of them are molecules involved in tumour cell recognition such as MICA/B and CD95. Other markers associated with immune system escape, such as CD39, CD73, and CTLA-4, were also present. Furthermore, we found that some cervical cancer cells expressed typical markers of NK cells like NKp30, NKp46, NKG2A, and KIR3DL1. It is not clear whether these molecules confer any gain to the tumour cells or if they represent a disadvantage, but we hypothesise that these molecules that are present in cervical cancer cells allow them to mimic in front of the immune system.


Assuntos
Papillomavirus Humano 16/fisiologia , Papillomavirus Humano 18/fisiologia , Células Matadoras Naturais/imunologia , Infecções por Papillomavirus/metabolismo , Neoplasias do Colo do Útero/metabolismo , 5'-Nucleotidase/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Antígeno CTLA-4/metabolismo , Feminino , Células HeLa , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Vigilância Imunológica , Receptores de Células Matadoras Naturais/metabolismo , Evasão Tumoral , Receptor fas/metabolismo
6.
Nat Commun ; 10(1): 2383, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31160595

RESUMO

DNA is an emerging medium for digital data and its adoption can be accelerated by synthesis processes specialized for storage applications. Here, we describe a de novo enzymatic synthesis strategy designed for data storage which harnesses the template-independent polymerase terminal deoxynucleotidyl transferase (TdT) in kinetically controlled conditions. Information is stored in transitions between non-identical nucleotides of DNA strands. To produce strands representing user-defined content, nucleotide substrates are added iteratively, yielding short homopolymeric extensions whose lengths are controlled by apyrase-mediated substrate degradation. With this scheme, we synthesize DNA strands carrying 144 bits, including addressing, and demonstrate retrieval with streaming nanopore sequencing. We further devise a digital codec to reduce requirements for synthesis accuracy and sequencing coverage, and experimentally show robust data retrieval from imperfectly synthesized strands. This work provides distributive enzymatic synthesis and information-theoretic approaches to advance digital information storage in DNA.


Assuntos
Apirase/metabolismo , DNA Nucleotidilexotransferase/metabolismo , DNA/síntese química , Armazenamento e Recuperação da Informação/métodos , Nanoporos , Análise de Sequência de DNA
7.
Biochem J ; 476(11): 1637-1651, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31085558

RESUMO

Extracellular ATP (eATP) and its metabolites have emerged as key modulators of different diseases and comprise a complex pathway called purinergic signaling. An increased number of tools have been developed to study the role of nucleotides and nucleosides in cell proliferation and migration, influence on the immune system and tumor progression. These tools include receptor agonists/antagonists, engineered ectonucleotidases, interference RNAs and ectonucleotidase inhibitors that allow the control and quantification of nucleotide levels. NTPDase1 (also called apyrase, ecto-ATPase and CD39) is one of the main enzymes responsible for the hydrolysis of eATP, and purified enzymes, such as apyrase purified from potato, or engineered as soluble CD39 (SolCD39), have been widely used in in vitro and in vivo experiments. However, the commercial apyrase had its effects recently questioned and SolCD39 exhibits limitations, such as short half-life and need of high doses to reach the expected enzymatic activity. Therefore, this study investigated a non-viral method to improve the overexpression of SolCD39 and evaluated its impact on other enzymes of the purinergic system. Our data demonstrated that PiggyBac transposon system proved to be a fast and efficient method to generate cells stably expressing SolCD39, producing high amounts of the enzyme from a limited number of cells and with high hydrolytic activity. In addition, the soluble form of NTPDase1/CD39 did not alter the expression or catalytic activity of other enzymes from the purinergic system. Altogether, these findings set the groundwork for prospective studies on the function and therapeutic role of eATP and its metabolites in physiological and pathological conditions.


Assuntos
Antígenos CD/química , Antígenos CD/metabolismo , Apirase/química , Apirase/metabolismo , Animais , Antígenos CD/genética , Apirase/genética , Linhagem Celular , Elementos de DNA Transponíveis/genética , Nucleotídeos/metabolismo , Ratos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Solubilidade , Transfecção , Regulação para Cima
8.
Blood Cells Mol Dis ; 77: 142-148, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31075617

RESUMO

BACKGROUND: We previously demonstrated CD133+ bone marrow stem cells (BMSC) to promote hepatic proliferation for liver regeneration. Here, we evaluated the capacity of CD133+BMSC to utilize platelets for homing to vasculature and concomitant controlling their aggregability upon ADP stimulation. METHODS: CD133+BMSC and platelets were co-cultured along micro endothelial cells under variable flow conditions and tested for homing levels along vasculature. Aggregometry and FACS analysis were utilized to evaluate platelet reactivity following co-incubation ±â€¯CD133+BMSC. RT-PCR and FACS analyses served to characterize ADP degrading ectonucleoside triphosphate diphosphohydrolase-1 (ectoNTPDase-1/CD39) expression on various cell types. RESULTS: Platelets attracted human CD133+BMSC to autologous micro endothelium under shear stress unaffected by ADP stimulation. However, CD133+BMSC inhibited ADP-mediated platelet activation and aggregation. Latter was dependent on ectoNTPDase-1 expression levels. Platelet aggregatory control was increased with CD133+BMSC compared to CD133+PHSC. Different effects of those stem cell subtypes positively correlated with their FACS-detected expression levels of ectoNTPDase-1. CONCLUSION: We provide evidence that CD133+BMSC are capable of controlling ADP-dependent platelet aggregation and activation by direct interaction dependent on cellular expression of ectoNTPDase-1. Whether different capacities of BMSC modulate platelet-depending thrombogenicity at sites of regeneration impact effectiveness and adverse event profiles of regenerative treatment requires further evaluation.


Assuntos
Antígeno AC133/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Plaquetas/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Ativação Plaquetária , Difosfato de Adenosina/metabolismo , Comunicação Celular , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Fibroblastos/metabolismo , Humanos , Regeneração Hepática , Agregação Plaquetária
9.
EBioMedicine ; 43: 620-631, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31076346

RESUMO

BACKGROUND: Bone destruction is one of many severe complications that occurs in patients with rheumatoid arthritis (RA) and current therapies are unable to cure this manifestation. This study here aims to determine whether GMSC can directly inhibit osteoclast formation and eventually attenuate osteoclastogenesis and bone erosion in an inflammatory milieu. METHOD: GMSC were co-cultured with osteoclast precursors with or without CD39 inhibitor, CD73 inhibitor or adenosine receptors inhibitors pretreatment and osteoclast formation were evaluated in vitro. 2×10^6 GMSC per mouse were transferred to CIA mice and pathology scores, the frequency of osteoclasts, bone erosion in joints were assessed in vivo. FINDING: GMSC but not control cells, markedly suppressed human or mice osteoclastogenesis in vitro. GMSC treatment also resulted in a dramatically decreased level of NF-κB p65/p50 in osteoclasts in vitro. Infusion of GMSC to CIA significantly attenuated the severity of arthritis, pathology scores, frequency of osteoclasts, particularly bone erosion, as well as a decreased expression of RANKL in synovial tissues in vivo. Blockade of CD39/CD73 or adenosine receptors has significantly abrogated the suppressive ability of GMSC in vitro and therapeutic effect of GMSC on bone erosion during CIA in vivo. INTERPRETATION: GMSC inhibit osteoclast formation in vitro and in vivo partially via CD39-CD73-adenosine signals. Manipulation of GMSC may have a therapeutic implication on rheumatoid arthritis and other bone erosion related diseases. FUND: This study was supported by grants from the National Key R&D Program of China (2017YFA0105801 to F.H); the Zhujiang Innovative and Entrepreneurial Talent Team Award of Guangdong Province (2016 ZT 06S 252 to F·H) and National Institutes of Health (R01 AR059103, R61 AR073409 and NIH Star Award to S.G.Z).


Assuntos
Adenosina/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Gengiva/citologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Transdução de Sinais , Animais , Artrite Experimental , Artrite Reumatoide/diagnóstico por imagem , Artrite Reumatoide/etiologia , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Doenças Autoimunes/diagnóstico por imagem , Doenças Autoimunes/etiologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Biomarcadores , Linhagem Celular , Feminino , Fibroblastos/metabolismo , Humanos , Camundongos , Osteoclastos/metabolismo , Tomografia Computadorizada por Raios X
10.
Nat Neurosci ; 22(5): 729-740, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30962630

RESUMO

Tumor-associated macrophages (TAMs) play an important role in the immune response to cancer, but the mechanisms by which the tumor microenvironment controls TAMs and T cell immunity are not completely understood. Here we report that kynurenine produced by glioblastoma cells activates aryl hydrocarbon receptor (AHR) in TAMs to modulate their function and T cell immunity. AHR promotes CCR2 expression, driving TAM recruitment in response to CCL2. AHR also drives the expression of KLF4 and suppresses NF-κB activation in TAMs. Finally, AHR drives the expression of the ectonucleotidase CD39 in TAMs, which promotes CD8+ T cell dysfunction by producing adenosine in cooperation with CD73. In humans, the expression of AHR and CD39 was highest in grade 4 glioma, and high AHR expression was associated with poor prognosis. In summary, AHR and CD39 expressed in TAMs participate in the regulation of the immune response in glioblastoma and constitute potential targets for immunotherapy.


Assuntos
Antígenos CD/metabolismo , Apirase/metabolismo , Neoplasias Encefálicas/imunologia , Glioblastoma/imunologia , Cinurenina/metabolismo , Macrófagos/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Linfócitos T/metabolismo , Animais , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Progressão da Doença , Glioblastoma/metabolismo , Humanos , Receptores de Lipopolissacarídeos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/metabolismo , Fator de Transcrição STAT1 , Fator de Transcrição STAT3/metabolismo , Linfócitos T/imunologia , Microambiente Tumoral
11.
J Insect Physiol ; 116: 10-16, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30986373

RESUMO

Mosquitoes infected by sporozoites, the infectious stage of malaria, bite more frequently than uninfected mosquitoes. One of the mechanisms underlying this behavioural change appears to be that the sporozoites decrease the activity of apyrase, an ADP-degrading enzyme that helps the mosquitoes to locate blood. Using the parasite Plasmodium berghei and the mosquito Anopheles gambiae, we confirmed that sporozoite infection alters the host-seeking behaviour of mosquitoes by making them more likely to refeed after a first blood meal, and that apyrase activity is one of the mechanisms of the increased biting persistence and motivation of infectious mosquitoes. We further showed that apyrase activity decreases as the sporozoite load increases, and that mosquitoes with lower apyrase activity take up less blood, making it more likely that they would return to top up their blood meal. Finally, by comparing full-sib families of mosquitoes, we showed that there was genetic variation for apyrase activity, but not for the resistance of parasites to be manipulated. Our results give new insights in understanding how malaria parasites change their hosts to affect their own transmission.


Assuntos
Anopheles/enzimologia , Anopheles/parasitologia , Apirase/genética , Proteínas de Insetos/genética , Animais , Apirase/metabolismo , Proteínas de Insetos/metabolismo , Mosquitos Vetores/enzimologia , Mosquitos Vetores/parasitologia , Carga Parasitária , Glândulas Salivares/enzimologia , Glândulas Salivares/parasitologia
12.
Int J Biol Macromol ; 131: 691-696, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30902720

RESUMO

The present manuscript describes a novel bioassay consisting of apyrase and heat shock protein 90 (Hsp90) without additional co-chaperone supplementation; intended for high-throughput screening of anti-cancer drugs and prognosis of stress. In this regard, Hsp90 and adenosine 5'-triphosphate (ATP) mediated firefly luciferase (FLuc) kinetics was investigated using apyrase and FLuc as client proteins. Bioluminescent assay containing Hsp90, ATP, and apyrase led to complete loss of luminescence at 50 °C which indicates the protective role of Hsp90 against thermal denaturation. Similarly, the assay sample comprising Hsp90, ATP, and FLuc showed 2 fold increments in luminescence than their counterparts. Introduction of bovine serum albumin (BSA) to the pre-incubated assay mixture led to an initial rise in the luminescence (28%) in comparison to the sample containing Hsp90, ATP and FLuc. Therefore, FLuc based HTS assays are not suitable for clinical samples which may contain stabilizing agents. However, thermally denatured FLuc and apyrase could not regain their active conformation even when Hsp90 and ATP were introduced in the assay system. This observation justifies the role of Hsp90 to be protective rather than a reparation agent when acts without co-chaperones.


Assuntos
Trifosfato de Adenosina/metabolismo , Apirase/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Luciferases de Vaga-Lume/metabolismo , Ativação Enzimática , Cinética , Chaperonas Moleculares/metabolismo , Ligação Proteica , Dobramento de Proteína , Redobramento de Proteína , Temperatura Ambiente
13.
Hum Immunol ; 80(7): 517-522, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30853363

RESUMO

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; n = 10) and dilated cardiomyopathy (CARD; n = 10). Healthy T. cruzi-negative individuals (NI; n = 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 Sorológicos
14.
Am J Physiol Endocrinol Metab ; 317(1): E25-E41, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30912960

RESUMO

Fructose is widely used as a sweetener in processed food and is also associated with metabolic disorders, such as obesity. However, the underlying cellular mechanisms remain unclear, in particular, regarding the pancreatic ß-cell. Here, we investigated the effects of chronic exposure to fructose on the function of insulinoma cells and isolated mouse and human pancreatic islets. Although fructose per se did not acutely stimulate insulin exocytosis, our data show that chronic fructose rendered rodent and human ß-cells hyper-responsive to intermediate physiological glucose concentrations. Fructose exposure reduced intracellular ATP levels without affecting mitochondrial function, induced AMP-activated protein kinase activation, and favored ATP release from the ß-cells upon acute glucose stimulation. The resulting increase in extracellular ATP, mediated by pannexin1 (Panx1) channels, activated the calcium-mobilizer P2Y purinergic receptors. Immunodetection revealed the presence of both Panx1 channels and P2Y1 receptors in ß-cells. Addition of an ectonucleotidase inhibitor or P2Y1 agonists to naïve ß-cells potentiated insulin secretion stimulated by intermediate glucose, mimicking the fructose treatment. Conversely, the P2Y1 antagonist and Panx1 inhibitor reversed the effects of fructose, as confirmed using Panx1-null islets and by the clearance of extracellular ATP by apyrase. These results reveal an important function of ATP signaling in pancreatic ß-cells mediating fructose-induced hyper-responsiveness.


Assuntos
Trifosfato de Adenosina/fisiologia , Frutose/farmacologia , Glucose/farmacologia , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Apirase/metabolismo , Conexinas/genética , Conexinas/metabolismo , Humanos , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Agonistas do Receptor Purinérgico P2Y/farmacologia , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Receptores Purinérgicos P2Y/efeitos dos fármacos , Receptores Purinérgicos P2Y/metabolismo , Receptores Purinérgicos P2Y1/efeitos dos fármacos , Receptores Purinérgicos P2Y1/metabolismo
16.
Immunobiology ; 224(3): 419-426, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30803848

RESUMO

Systemic lupus erythematosus (SLE) is an autoimmune and inflammatory disease with periods of exacerbation and remission. SLE is characterized by the irreversible breakdown of immunological self-tolerance, where there is deregulation of multiple aspects of the immune system. SLE immune dysfunction is characterized by activation of autoreactive T lymphocytes, and hyperactivity of B lymphocytes with consequent production of several autoantibodies. ATP is a purinergic mediator released into the extracellular space in response to cell and tissue damage which operates as a danger signal to modulate immune and inflammatory responses. ATP binds to P2 receptors and its levels are regulated by NTPDase (CD39). SLE patients exhibit increased levels of ATP which binds to P2X receptors resulting in activation of the inflammasome and consequent release of IL-1ß and IL-18, cytokines associated with disease pathogenesis. CD39 is upregulated in SLE representing an important immunoregulatory mechanism by controlling inflammation and favoring the production of adenosine. The aim of this review is to clarify the effects of ATP on the modulation of the inflammatory process and immune responses via P2 receptors as well as the role of NTPDase in the immunopathogenesis of SLE.


Assuntos
Trifosfato de Adenosina/metabolismo , Antígenos CD/metabolismo , Apirase/metabolismo , Linfócitos T CD4-Positivos/imunologia , Inflamação/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Animais , Humanos , Receptores Purinérgicos P2X/metabolismo , Tolerância a Antígenos Próprios , Transdução de Sinais
17.
Int J Mol Sci ; 20(3)2019 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-30691212

RESUMO

Exact causes for autoimmune diseases remain unclear and no cures are available. Breakdown of immunotolerance could set the stage for unfettered immune responses that target self-antigens. Impaired regulatory immune mechanisms could have permissive roles in autoreactivity. Abnormal regulatory immune cell function, therefore, might be a major determinant of the pathogenesis of autoimmune disease. All current treatments are associated with some level of clinical toxicity. Treatment to specifically target dysregulated immunity in these diseases would be a great advance. Extracellular adenosine is a signaling mediator that suppresses inflammation through activation of P1 receptors, most active under pathological conditions. Mounting evidence has linked alterations in the generation of adenosine from extracellular nucleotides by ectonucleotidases, and associated perturbations in purinergic signaling, to the immunological disruption and loss of immunotolerance in autoimmunity. Targeted modulation of the purinergic signaling by either targeting ectonucleotidases or modulating P1 purinergic receptors could therefore restore the balance between autoreactive immune responses; and thereby allow reestablishment of immunotolerance. We review the roles of CD39 and CD73 ectoenzymes in inflammatory states and with the dysregulation of P1 receptor signaling in systemic and organ-specific autoimmunity. Correction of such perturbations could be exploited in potential therapeutic applications.


Assuntos
Antígenos de Neoplasias/metabolismo , Apirase/metabolismo , Doenças Autoimunes/metabolismo , Receptores Purinérgicos P1/metabolismo , Tetraspaninas/metabolismo , Adenosina/metabolismo , Doenças Autoimunes/tratamento farmacológico , Humanos , Especificidade de Órgãos , Transdução de Sinais
18.
Microb Pathog ; 128: 323-328, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30660734

RESUMO

BACKGROUND: Chronic HBV infection presents weak or no virus-specific T-cell responses, implying to an exhausted phenotype, characterized by overexpression of several inhibitory receptors. In the present study, it was aimed to characterize the panel of inhibitory molecules on the CD8+ T cells in patients with active chronic HBV infection. METHODS: In this study, 31 active and 32 inactive individuals with chronic HBV infection were recruited. Peripheral blood mononuclear cells were isolated and a multicolor flow cytometry was applied to evaluate the surface inhibitory molecules of TIM3, PD-1, and CD39. RESULTS: CD8+ T cells expressing TIM3 were significantly higher in cases with active chronic HBV infection compared to inactive chronic HBV group (8.43 ±â€¯1.4 vs. 5.15 ±â€¯1.43; P < 0.0001). CD8+TIM3+PD-1+ T cells were significantly higher in active chronic HBV cases in comparison to the inactive chronic HBV subjects (4.26 ±â€¯1.04 vs. 3.41 ±â€¯0.74; P < 0.001). Different subpopulations of the CD8+ T cells were correlated with the duration of infection and HBV DNA load in the cases with active chronic HBV infection. CONCLUSION: It appears that CD8+ TIM3+ T cells are the major exhausted phenotype of T cells during the active state of HBV infection.


Assuntos
Biomarcadores , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/sangue , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Hepatite B Crônica/sangue , Hepatite B Crônica/imunologia , Adulto , Apirase/metabolismo , Feminino , Citometria de Fluxo , Vírus da Hepatite B/patogenicidade , Humanos , Leucócitos Mononucleares , Masculino , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/metabolismo , Carga Viral
19.
Nat Commun ; 10(1): 250, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30651557

RESUMO

T cell dependent secretory IgA (SIgA) generated in the Peyer's patches (PPs) of the small intestine shapes a broadly diverse microbiota that is crucial for host physiology. The mutualistic co-evolution of host and microbes led to the relative tolerance of host's immune system towards commensal microorganisms. The ATP-gated ionotropic P2X7 receptor limits T follicular helper (Tfh) cells expansion and germinal center (GC) reaction in the PPs. Here we show that transient depletion of intestinal ATP can dramatically improve high-affinity IgA response against both live and inactivated oral vaccines. Ectopic expression of Shigella flexneri periplasmic ATP-diphosphohydrolase (apyrase) abolishes ATP release by bacteria and improves the specific IgA response against live oral vaccines. Antibody responses primed in the absence of intestinal extracellular ATP (eATP) also provide superior protection from enteropathogenic infection. Thus, modulation of eATP in the small intestine can affect high-affinity IgA response against gut colonizing bacteria.


Assuntos
Trifosfato de Adenosina/metabolismo , Gastroenterite/imunologia , Microbioma Gastrointestinal/fisiologia , Imunoglobulina A Secretora/metabolismo , Infecções por Salmonella/imunologia , Trifosfato de Adenosina/imunologia , Administração Oral , Animais , Apirase/imunologia , Apirase/metabolismo , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/imunologia , Modelos Animais de Doenças , Escherichia coli/imunologia , Escherichia coli/metabolismo , Feminino , Gastroenterite/microbiologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Humanos , Íleo/imunologia , Íleo/metabolismo , Íleo/microbiologia , Imunoglobulina A Secretora/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/metabolismo , Receptores Purinérgicos P2X7/imunologia , Receptores Purinérgicos P2X7/metabolismo , Infecções por Salmonella/microbiologia , Salmonella typhimurium/imunologia , Salmonella typhimurium/patogenicidade , Shigella flexneri/imunologia , Shigella flexneri/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo
20.
Cell Death Dis ; 10(1): 13, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30622237

RESUMO

Human gingival tissue-derived mesenchymal stem cells (GMSCs) present an accessible source of mesenchymal stem cells (MSCs) for treating autoimmune diseases. Here we show that human GMSCs can prevent and treat acute graft-versus-host disease (GVHD) in two different mouse models. Our results indicate that besides exhibiting suppressive function in vitro and in vivo, GMSCs may also regulate the conversion of Tregs to Th1 and/or Th17-like cells, as well as stabilize Foxp3 expression. Furthermore, GMSC-mediated prevention of acute GVHD was dependent on CD39 signaling that play an important role in the function and stability of Tregs. Finally, we also observed stronger protective ability of GMSCs with greater expansion ability compared with BMSCs or ASCs. These results indicate that human GMSCs have the potential to be used to treat GVHD.


Assuntos
Antígenos CD/metabolismo , Apirase/metabolismo , Gengiva/citologia , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Mesenquimais , Índice de Gravidade de Doença , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/genética , Técnicas de Introdução de Genes , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Células Th1/imunologia , Células Th17/imunologia
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