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BACKGROUND: Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, which promotes a sustained inflammatory environment in the central nervous system. Regulatory T cells (Tregs) play an important role in the control of inflammation and might play a neuroprotective role. Indeed, a decrease in Treg number and function has been reported in PD. In this context, pramipexole, a dopaminergic receptor agonist used to treat PD symptoms, has been shown to increase peripheral levels of Treg cells and improve their suppressive function. The aim of this work was to determine the effect of pramipexole on immunoregulatory Treg cells and its possible neuroprotective effect on human dopaminergic neurons differentiated from human embryonic stem cells. METHODS: Treg cells were sorted from white blood cells of healthy human donors. Assays were performed with CD3/CD28-activated and non-activated Treg cells treated with pramipexole at concentrations of 2 or 200 ng/mL. These regulatory cells were co-cultured with in vitro-differentiated human dopaminergic neurons in a cytotoxicity assay with 6-hydroxydopamine (6-OHDA). The role of interleukin-10 (IL-10) was investigated by co-culturing activated IL-10-producing Treg cells with neurons. To further investigate the effect of treatment on Tregs, gene expression in pramipexole-treated, CD3/CD28-activated Treg cells was determined by Fluidigm analysis. RESULTS: Pramipexole-treated CD3/CD28-activated Treg cells showed significant protective effects on dopaminergic neurons when challenged with 6-OHDA. Pramipexole-treated activated Treg cells showed neuroprotective capacity through mechanisms involving IL-10 release and the activation of genes associated with regulation and neuroprotection. CONCLUSION: Anti-CD3/CD28-activated Treg cells protect dopaminergic neurons against 6-OHDA-induced damage. In addition, activated, IL-10-producing, pramipexole-treated Tregs also induced a neuroprotective effect, and the supernatants of these co-cultures promoted axonal growth. Pramipexole-treated, activated Tregs altered their gene expression in a concentration-dependent manner, and enhanced TGFß-related dopamine receptor regulation and immune-related pathways. These findings open new perspectives for the development of immunomodulatory therapies for the treatment of PD.
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Benzotiazóis , Neurônios Dopaminérgicos , Oxidopamina , Pramipexol , Linfócitos T Reguladores , Humanos , Pramipexol/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Oxidopamina/toxicidade , Benzotiazóis/farmacologia , Técnicas de Cocultura , Interleucina-10/metabolismo , Células Cultivadas , Fármacos Neuroprotetores/farmacologia , Agonistas de Dopamina/farmacologiaRESUMO
This is a case report of a young adult who died of COVID-19 twelve days after admission, with coronavirus nucleocapsid protein and lipofuscin found in the heart and kidney tissues, providing further evidence of the role of SARS-CoV-2 in cellular senescence.
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The disease burden of arthropod-borne infections is particularly high in low- and middle-income countries, where the availability of resources for surveillance and testing is limited. The lack of local infrastructure demands that biological samples be sent to central laboratories by refrigerated transport, which increases costs and the risk of sample degradation. Dried blood spot samples are an alternative for ensuring sample integrity during transportation and storage. They can be used for the detection of nucleic acids and proteins, such as antigens or antibodies. Here, we compared anti-chikungunya IgM, anti-dengue IgM, anti-dengue IgG, and anti-Zika IgG detection between paired serum and dried serum samples (DSSs); the agreement between results was found to be 90.6%, 94.1%, 85.9%, and 95.5%, respectively, indicating a strong correlation. Our results suggest that DSSs provide a reliable alternative for detection of specific antibodies in arthropod-borne infections.
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The PDZ (PSD95, Dlg and ZO-1) genes encode proteins that primarily function as scaffolds of diverse signaling pathways. To date, 153 PDZ genes have been identified in the human genome, most of which have multiple protein isoforms widely studied in epithelial and neural cells. However, their expression and function in immune cells have been poorly studied. Herein, we aimed to assess the transcriptional profiles of 83 PDZ genes in human macrophages (Mɸ) and dendritic cells (DCs) and changes in their relative expression during cell PRR stimulation. Significantly distinct PDZ gene transcriptional profiles were identified under different stimulation conditions. Furthermore, a distinct PDZ gene transcriptional signature was found in Mɸ and DCs under the same phagocytic stimuli. Notably, more than 40 PDZ genes had significant changes in expression, with potentially relevant functions in antigen-presenting cells (APCs). Given that several PDZ proteins are targeted by viral products, our results support that many of these proteins might be viral targets in APCs as part of evasion mechanisms. Our results suggest a distinct requirement for PDZ scaffolds in Mɸ and DCs signaling pathways activation. More assessments on the functions of PDZ proteins in APCs and their role in immune evasion mechanisms are needed.
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Evasão da Resposta Imune , Macrófagos , Células Dendríticas , Humanos , Macrófagos/metabolismo , Transdução de SinaisRESUMO
Murine cysticercosis by Taenia crassiceps is a model for human neurocysticercosis. Genetic and/or immune differences may underlie the higher susceptibility to infection in BALB/cAnN with respect to C57BL/6 mice. T regulatory cells (Tregs) could mediate the escape of T. crassiceps from the host immunity. This study is aimed to investigate the role of Tregs in T. crassiceps establishment in susceptible and non-susceptible mouse strains. Treg and effector cells were quantified in lymphoid organs before infection and 5, 30, 90, and 130 days post-infection. The proliferative response post-infection was characterized in vitro. The expression of regulatory and inflammatory molecules was assessed on days 5 and 30 post-infection. Depletion assays were performed to assess Treg functionality. Significantly higher Treg percentages were observed in BALB/cAnN mice, while increased percentages of activated CD127+ cells were found in C57BL/6 mice. The proliferative response was suppressed in susceptible mice, and Treg proliferation occurred only in susceptible mice. Treg-mediated suppression mechanisms may include IL-10 and TGFß secretion, granzyme- and perforin-mediated cytolysis, metabolic disruption, and cell-to-cell contact. Tregs are functional in BALB/cAnN mice. Therefore Tregs could be allowing parasite establishment and survival in susceptible mice but could play a homeostatic role in non-susceptible strains.
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Linfócitos T Reguladores , Taenia , Animais , Imunidade , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
To date, mother-to-fetus transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease 2019 (COVID-19) pandemic, remains controversial. Although placental COVID-19 infection has been documented in some cases during the second- and third-trimesters, no reports are available for the first trimester of pregnancy, and no SARS-CoV-2 protein has been found in fetal tissues. We studied the placenta and fetal organs from an early pregnancy miscarriage in a COVID-19 maternal infection by immunohistochemical, reverse transcription quantitative real-time polymerase chain reaction, immunofluorescence, and electron microscopy methods. SARS-CoV-2 nucleocapsid protein, viral RNA, and particles consistent with coronavirus were found in the placenta and fetal tissues, accompanied by RNA replication revealed by double-stranded RNA (dsRNA) positive immunostain. Prominent damage of the placenta and fetal organs were associated with a hyperinflammatory process identified by histological examination and immunohistochemistry. The findings provided in this study document that congenital SARS-CoV-2 infection is possible during the first trimester of pregnancy and that fetal organs, such as lung and kidney, are targets for coronavirus. The infection and multi-organic fetal inflammation produced by SARS-CoV-2 during early pregnancy should alert clinicians in the assessment and management of pregnant women for possible fetal consequences and adverse perinatal outcomes.
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COVID-19/transmissão , Transmissão Vertical de Doenças Infecciosas , Placenta/virologia , Complicações Infecciosas na Gravidez/virologia , SARS-CoV-2/metabolismo , Aborto Espontâneo/virologia , Adulto , COVID-19/patologia , Feminino , Feto/patologia , Feto/virologia , Humanos , Placenta/patologia , Gravidez , Resultado da Gravidez , Primeiro Trimestre da Gravidez , Gestantes , RNA Viral/análiseRESUMO
We characterized natural vertical transmission of Zika virus in pools of Aedes aegypti larvae hatched from eggs collected in Jojutla, Morelos, Mexico. Of the 151 pools analyzed, 17 tested positive for Zika virus RNA; infectious Zika virus was successfully isolated from 1 of the larvae pools (31N) in C6/36 cells. Real-time quantitative PCR and indirect immunofluorescence assays confirmed the identity of the isolate, named Zika virus isolate 31N; plaque assays in Vero cells demonstrated the isolate's infectivity in a mammalian cell line. We obtained the complete genome of Zika virus isolate 31N by next-generation sequencing and identified 3 single-nucleotide variants specific to Zika virus isolate 31N using the meta-CATS tool. These results demonstrate the occurrence of natural vertical transmission of Zika virus in wild Ae. aegypti mosquitoes and suggest that this transmission mode could aid in the spread and maintenance of Zika virus in nature.
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Aedes/virologia , Mosquitos Vetores/virologia , Zika virus/fisiologia , Animais , Linhagem Celular , Células Cultivadas , Chlorocebus aethiops , Microbiologia Ambiental , Genoma Viral , Humanos , Transmissão Vertical de Doenças Infecciosas , Larva , México/epidemiologia , Filogenia , Vigilância em Saúde Pública , Células Vero , Carga Viral , Ensaio de Placa Viral , Sequenciamento Completo do Genoma , Zika virus/classificação , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologiaRESUMO
OBJECTIVE: Parkinson's disease (PD) patients are usually treated with L-dopa and/or dopaminergic agonists, which act by binding five types of dopaminergic receptors (DRD1-DRD5). Peripheral immune cells are known to express dopamine receptors on their membrane surface, and therefore they could be directly affected by the treatment. Regulatory cells are the main modulators of inflammation, but it is not clear whether dopaminergic treatment could affect their functions. While only regulatory T cells (Tregs) have been proved to express dopamine receptors, it is not known whether other regulatory cells such as CD8regs, regulatory B cells (Bregs), tolerogenic dendritic cells, and intermediate monocytes also express them. METHODS: The expression of dopamine receptors in Tregs, CD8regs, Bregs, tolerogenic dendritic cells, and intermediate monocytes was herein evaluated. cDNA from 11 PD patients and 9 control subjects was obtained and analyzed. RESULTS: All regulatory cell populations expressed the genes coding for dopamine receptors, and this expression was further corroborated by flow cytometry. These findings may allow us to propose regulatory populations as possible targets for PD treatment. CONCLUSIONS: This study opens new paths to deepen our understanding on the effect of PD treatment on the cells of the regulatory immune response.
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Linfócitos B Reguladores/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/metabolismo , Monócitos/metabolismo , Doença de Parkinson/metabolismo , Receptores Dopaminérgicos/metabolismo , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/imunologiaRESUMO
BACKGROUND: During pregnancy, the Zika virus (ZIKV) replicates in the placenta and central nervous system (CNS) of infected fetuses; nevertheless, the ability of ZIKV to replicate in other fetal tissues has not been extensively characterized. METHODS: We researched whether dissemination of congenitally-acquired ZIKV outside the CNS exists by searching for the accumulation of the viral envelope protein, ZIKV ribonucleic acid (RNA), and infectious viral particles in different organs of a deceased newborn with Congenital Zika Syndrome. A real-time qualitative polymerase chain reaction (qPCR) was used to detect ZIKV RNA in the brain, thymus, lungs, kidneys, adrenal glands, spleen, liver, and small intestine. The same tissues were analyzed by indirect immunofluorescence and immunoperoxidase assays using the monoclonal antibody 4G2 to detect ZIKV envelope antigens. Isolation of infectious ZIKV in a cell culture was carried out using brain and kidney samples. RESULTS: A postmortem, virological analysis of multiple organs, such as the kidneys (epithelial cells in the renal tubules), lungs (bronchial epithelia), thymus (epithelial cells inside the Hassall's corpuscles), and brain (neurons, ependymal cells, and macrophages) revealed the presence of ZIKV RNA and envelope antigens. Other tissues of the deceased newborn tested positive by qPCR for Epstein-Barr virus and human herpesvirus 6, including the brain cortex (Epstein-Barr) and the thymus, kidneys, and adrenal glands (human herpesvirus 6). The kidneys were identified as a significant niche for viral replication, given that infectious particles were successfully isolated from renal tissues. CONCLUSIONS: Our findings demonstrate the ability of congenitally-acquired ZIKV to produce disseminated infections and the viral tropism towards epithelial cells.
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Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/virologia , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/virologia , Zika virus/genética , Antígenos Virais , Autopsia , Biópsia , Coinfecção , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Transmissão Vertical de Doenças Infecciosas , Nefropatias/patologia , Nefropatias/virologia , México/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Vigilância em Saúde Pública , RNA Viral , Adulto Jovem , Zika virus/imunologia , Zika virus/ultraestrutura , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissãoRESUMO
Antibodies to Zika virus (ZIKV) can be protective. To examine the antibody response in individuals who develop high titers of anti-ZIKV antibodies, we screened cohorts in Brazil and Mexico for ZIKV envelope domain III (ZEDIII) binding and neutralization. We find that serologic reactivity to dengue 1 virus (DENV1) EDIII before ZIKV exposure is associated with increased ZIKV neutralizing titers after exposure. Antibody cloning shows that donors with high ZIKV neutralizing antibody titers have expanded clones of memory B cells that express the same immunoglobulin VH3-23/VK1-5 genes. These recurring antibodies cross-react with DENV1, but not other flaviviruses, neutralize both DENV1 and ZIKV, and protect mice against ZIKV challenge. Structural analyses reveal the mechanism of recognition of the ZEDIII lateral ridge by VH3-23/VK1-5 antibodies. Serologic testing shows that antibodies to this region correlate with serum neutralizing activity to ZIKV. Thus, high neutralizing responses to ZIKV are associated with pre-existing reactivity to DENV1 in humans.