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1.
Cell Mol Neurobiol ; 44(1): 31, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38557942

ABSTRACT

Glioblastoma multiforme (GBM) is the most predominant and malignant primary brain tumor in adults. Thymic stromal lymphopoietin (TSLP), a cytokine primarily generated by activated epithelial cells, has recently garnered attention in cancer research. This study was aimed to elucidate the significance of TSLP in GBM cells and its interplay with the immune system, particularly focused on granulocyte neutrophils. Our results demonstrate that the tumor produces TSLP when stimulated with epidermal growth factor (EGF) in both the U251 cell line and the GBM biopsy (GBM-b). The relevance of the TSLP function was evaluated using a 3D spheroid model. Spheroids exhibited increased diameter, volume, and proliferation. In addition, TSLP promoted the generation of satellites surrounding the main spheroids and inhibited apoptosis in U251 treated with temozolomide (TMZ). Additionally, the co-culture of polymorphonuclear (PMN) cells from healthy donors with the U251 cell line in the presence of TSLP showed a reduction in apoptosis and an increase in IL-8 production. TSLP directly inhibited apoptosis in PMN from GBM patients (PMN-p). Interestingly, the vascular endothelial growth factor (VEGF) production was elevated in PMN-p compared with PMN from healthy donors. Under these conditions, TSLP also increased VEGF production, in PMN from healthy donors. Moreover, TSLP upregulated programed death-ligand 1 (PDL-1) expression in PMN cultured with U251. On the other hand, according to our results, the analysis of RNA-seq datasets from Illumina HiSeq 2000 sequencing platform performed with TIMER2.0 webserver demonstrated that the combination of TSLP with neutrophils decreases the survival of the patient. In conclusion, our results position TSLP as a possible new growth factor in GBM and indicate its modulation of the tumor microenvironment, particularly through its interaction with PMN.


Subject(s)
Glioblastoma , Thymic Stromal Lymphopoietin , Adult , Humans , Cells, Cultured , Cytokines/metabolism , Neutrophils/metabolism , Tumor Microenvironment , Vascular Endothelial Growth Factor A
2.
J Infect Dis ; 227(3): 423-433, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36482781

ABSTRACT

BACKGROUND: Monocyte activation is a driver of inflammation in the course of chronic HIV infection. Prostaglandin E2 (PGE2) is known to mediate anti-inflammatory effects, notably the inhibition of tumor necrosis factor- (TNF-) production by monocytes. We aim to investigate the effects of PGE2 on activation of monocytes in chronic HIV infection and the mechanisms through which PGE2 modulates their inflammatory signature. METHODS: We recruited a group of people with HIV (PWH) and matched healthy uninfected persons. We compared plasma levels of PGE2, monocyte activation, and sensitivity of monocytes to the inhibitory actions mediated by PGE2. RESULTS: We found increased plasma levels of PGE2 in PWH, and an activated phenotype in circulating monocytes, compared with uninfected individuals. Monocytes from PWH showed a significant resistance to the inhibitory actions mediated by PGE2; the concentration of PGE2 able to inhibit 50 of the production of TNF- by lipopolysaccharide-stimulated monocytes was 10 times higher in PWH compared with uninfected controls. Furthermore, the expression of phosphodiesterase 4B, a negative regulator of PGE2 activity, was significantly increased in monocytes from PWH. CONCLUSIONS: Resistance to the inhibitory actions mediated by PGE2 could account, at least in part, for the inflammatory profile of circulating monocytes in PWH.


Subject(s)
Dinoprostone , HIV Infections , Humans , Dinoprostone/metabolism , Monocytes/metabolism , HIV Infections/metabolism , Tumor Necrosis Factor-alpha/metabolism , Gene Expression , Lipopolysaccharides
3.
J Infect Dis ; 225(3): 392-395, 2022 02 01.
Article in English | MEDLINE | ID: mdl-34850028

ABSTRACT

There is a paucity of reports on the characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in infants, because most studies have grouped infants with older children. We analyzed the viral loads of 45318 SARS-CoV-2-positive nasopharyngeal swab samples obtained in Buenos Aires, Argentina. Infants younger than 6 months presented higher viral loads than any other age group. Children older than 6 months showed significantly lower viral loads, similar to those founds in adults. This observation raises new questions regarding the role of infants in the spreading of SARS-CoV-2 infection.


Subject(s)
COVID-19 , Respiratory System/virology , SARS-CoV-2 , Viral Load , Argentina/epidemiology , COVID-19/diagnosis , Humans , Infant , SARS-CoV-2/isolation & purification
4.
Br J Haematol ; 197(3): 283-292, 2022 05.
Article in English | MEDLINE | ID: mdl-35076084

ABSTRACT

Severe COVID-19 is associated with a systemic inflammatory response and progressive CD4+ T-cell lymphopenia and dysfunction. We evaluated whether platelets might contribute to CD4+ T-cell dysfunction in COVID-19. We observed a high frequency of CD4+ T cell-platelet aggregates in COVID-19 inpatients that inversely correlated with lymphocyte counts. Platelets from COVID-19 inpatients but not from healthy donors (HD) inhibited the upregulation of CD25 expression and tumour necrosis factor (TNF)-α production by CD4+ T cells. In addition, interferon (IFN)-γ production was increased by platelets from HD but not from COVID-19 inpatients. A high expression of PD-L1 was found in platelets from COVID-19 patients to be inversely correlated with IFN-γ production by activated CD4+ T cells cocultured with platelets. We also found that a PD-L1-blocking antibody significantly restored platelets' ability to stimulate IFN-γ production by CD4+ T cells. Our study suggests that platelets might contribute to disease progression in COVID-19 not only by promoting thrombotic and inflammatory events, but also by affecting CD4+ T cells functionality.


Subject(s)
B7-H1 Antigen , COVID-19 , B7-H1 Antigen/metabolism , Blood Platelets/metabolism , CD4-Positive T-Lymphocytes , Humans , Interferon-gamma
5.
RNA Biol ; 18(12): 2218-2225, 2021 12.
Article in English | MEDLINE | ID: mdl-33966602

ABSTRACT

Early detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proven crucial during the efforts to mitigate the effects of the COVID-19 pandemic. Several diagnostic methods have emerged in the past few months, each with different shortcomings and limitations. The current gold standard, RT-qPCR using fluorescent probes, relies on demanding equipment requirements plus the high costs of the probes and specific reaction mixes. To broaden the possibilities of reagents and thermocyclers that could be allocated towards this task, we have optimized an alternative strategy for RT-qPCR diagnosis. This is based on a widely used DNA-intercalating dye and can be implemented with several different qPCR reagents and instruments. Remarkably, the proposed qPCR method performs similarly to the broadly used TaqMan-based detection, in terms of specificity and sensitivity, thus representing a reliable tool. We think that, through enabling the use of vast range of thermocycler models and laboratory facilities for SARS-CoV-2 diagnosis, the alternative proposed here can increase dramatically the testing capability, especially in countries with limited access to costly technology and reagents.


Subject(s)
Benzothiazoles/chemistry , COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Diamines/chemistry , Intercalating Agents/chemistry , Quinolines/chemistry , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , COVID-19/virology , COVID-19 Nucleic Acid Testing/standards , DNA/analysis , DNA/biosynthesis , DNA Primers/chemistry , DNA Primers/metabolism , Humans , Nasopharynx/virology , Real-Time Polymerase Chain Reaction/standards , Sensitivity and Specificity
8.
J Infect Dis ; 215(7): 1049-1058, 2017 Apr 01.
Article in English | MEDLINE | ID: mdl-28199704

ABSTRACT

BACKGROUND: Although human airway epithelial cells are the main target of respiratory syncytial virus (RSV), it also infects immune cells, such as macrophages and B cells. Whether T cells are permissive to RSV infection is unknown. We sought to analyze the permissiveness of CD4+ T cells to RSV infection. METHODS: CD4+ and CD8+ T cells from cord blood, healthy young children, and adults were challenged by RSV or cocultured with infected HEp-2 cells. Infection, phenotype, and cytokine production by T cells were analyzed by flow cytometry or enzyme-linked immunosorbent assay. Expression of RSV antigens by circulating CD4+ T cells from infected children was analyzed by flow cytometry, and disease severity was defined by standard criteria. RESULTS: CD4+ and CD8+ T cells were productively infected by RSV. Infection decreased interleukin 2 and interferon γ production as well as the expression of CD25 and Ki-67 by activated CD4+ T cells. Respiratory syncytial virus antigens were detected in circulating CD4+ and CD8+ T cells during severe RSV infection of young children. Interestingly, the frequency of CD4+ RSV+ T cells positively correlated with disease severity. CONCLUSIONS: Respiratory syncytial virus infects CD4+ and CD8+ T cells and compromises T-cell function. The frequency of circulating CD4+ RSV+ T cells might represent a novel marker of severe infection.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Respiratory Syncytial Virus Infections/immunology , Adult , Biomarkers/blood , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/virology , Cell Line , Female , Fetal Blood/cytology , Flow Cytometry , Humans , Infant , Infant, Newborn , Interferon-gamma/immunology , Interleukin-2/immunology , Male , Respiratory Syncytial Virus, Human
9.
J Immunol ; 193(6): 3165-74, 2014 Sep 15.
Article in English | MEDLINE | ID: mdl-25127862

ABSTRACT

Chronic lymphocytic leukemia (CLL) is characterized by the progressive accumulation of clonal B lymphocytes. Proliferation occurs in lymphoid tissues upon interaction of leukemic cells with a supportive microenvironment. Therefore, the mobilization of tissue-resident CLL cells into the circulation is a useful therapeutic strategy to minimize the reservoir of tumor cells within survival niches. Because the exit of normal lymphocytes from lymphoid tissues depends on the presence of sphingosine-1 phosphate (S1P) and the regulated expression of S1P receptor-1 (S1PR1), we investigated whether the expression and function of S1PR1 can be modulated by key microenvironment signals. We found that activation of CLL cells with CXCL12, fibroblast CD40L(+), BCR cross-linking, or autologous nurse-like cells reduces their S1PR1 expression and the migratory response toward S1P. Moreover, we found that S1PR1 expression was reduced in the proliferative/activated subset of leukemic cells compared with the quiescent subset from the same patient. Similarly, bone marrow-resident CLL cells expressing high levels of the activation marker CD38 showed a lower expression of S1PR1 compared with CD38(low) counterparts. Finally, given that treatment with BCR-associated kinase inhibitors induces a transient redistribution of leukemic cells from lymphoid tissues to circulation, we studied the effect of the Syk inhibitors piceatannol and R406 on S1PR1 expression and function. We found that they enhance S1PR1 expression in CLL cells and their migratory response toward S1P. Based on our results, we suggest that the regulated expression of S1PR1 might modulate the egress of the leukemic clone from lymphoid tissues.


Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Lysophospholipids/immunology , Oxazines/pharmacology , Pyridines/pharmacology , Receptors, Lysosphingolipid/immunology , Sphingosine/analogs & derivatives , Stilbenes/pharmacology , ADP-ribosyl Cyclase 1/biosynthesis , Adult , Aged , Aged, 80 and over , Animals , B-Lymphocytes , CD40 Ligand/biosynthesis , Cell Movement , Chemokine CXCL12/biosynthesis , Female , Gene Expression , Gene Expression Regulation, Neoplastic , Humans , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Lysophospholipids/biosynthesis , Male , Membrane Glycoproteins/biosynthesis , Mice , Middle Aged , Protein-Tyrosine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins c-bcr/biosynthesis , Receptors, CXCR4 , Receptors, Lysosphingolipid/biosynthesis , Sphingosine/biosynthesis , Sphingosine/immunology , Sphingosine-1-Phosphate Receptors , Syk Kinase , Tumor Cells, Cultured , Tumor Microenvironment
10.
J Immunol ; 189(10): 4777-86, 2012 Nov 15.
Article in English | MEDLINE | ID: mdl-23066152

ABSTRACT

Seminal plasma is not just a carrier for spermatozoa. It contains high concentrations of cytokines, chemokines, and other biological compounds that are able to exert potent effects on the immune system of the receptive partner. Previous studies have shown that semen induces an acute inflammatory response at the female genital mucosa after coitus. Moreover, it induces regulatory mechanisms that allow the fetus (a semiallograft) to grow and develop in the uterus. The mechanisms underlying these regulatory mechanisms, however, are poorly understood. In this study, we show that seminal plasma redirects the differentiation of human dendritic cells (DCs) toward a regulatory profile. DCs differentiated from human monocytes in the presence of high dilutions of seminal plasma did not express CD1a but showed high levels of CD14. They were unable to develop a fully mature phenotype in response to LPS, TNF-α, CD40L, Pam2CSK4 (TLR2/6 agonist), or Pam3CSK4 (TLR1/2 agonist). Upon activation, they produced low amounts of the inflammatory cytokines IL-12p70, IL-1ß, TNF-α, and IL-6, but expressed a high ability to produce IL-10 and TGF-ß. Inhibition of the PG receptors E-prostanoid receptors 2 and 4 prevented the tolerogenic effect induced by seminal plasma on the phenotype and function of DCs, suggesting that E-series PGs play a major role. By promoting a tolerogenic profile in DCs, seminal plasma might favor fertility, but might also compromise the capacity of the receptive partner to mount an effective immune response against sexually transmitted pathogens.


Subject(s)
Cell Differentiation/physiology , Dendritic Cells/immunology , Immune Tolerance/physiology , Monocytes/immunology , Semen/immunology , Adult , Antigens, CD1/immunology , Cell Differentiation/drug effects , Cytokines/immunology , Dendritic Cells/cytology , Female , Humans , Immune Tolerance/drug effects , Lipopolysaccharide Receptors/immunology , Lipopolysaccharides/pharmacology , Male , Monocytes/cytology , Receptors, Prostaglandin E, EP2 Subtype/antagonists & inhibitors , Receptors, Prostaglandin E, EP2 Subtype/immunology , Receptors, Prostaglandin E, EP4 Subtype/antagonists & inhibitors , Receptors, Prostaglandin E, EP4 Subtype/immunology
11.
J Immunol ; 187(10): 5299-309, 2011 Nov 15.
Article in English | MEDLINE | ID: mdl-22013110

ABSTRACT

The C-type lectin receptor dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) is an important player in the recognition of pathogens by dendritic cells. A plethora of pathogens including viruses, bacteria, parasites, and fungi are recognized by DC-SIGN through both mannose and fucose-containing glycans expressed on the pathogen surface. In this study, we identified semen clusterin as a novel DC-SIGN ligand. Semen clusterin, but not serum clusterin, expresses an extreme abundance of fucose-containing blood-type Ags such as Le(x) and Le(y), which are both excellent DC-SIGN ligands. These motifs enable semen clusterin to bind DC-SIGN with very high affinity (K(d) 76 nM) and abrogate the binding of HIV-1 to DC-SIGN. Depletion of clusterin from semen samples, however, did not completely prevent the ability of semen to inhibit the capture of HIV-1 by DC-SIGN, supporting that besides clusterin, semen contains other DC-SIGN ligands. Further studies are needed to characterize these ligands and define their contribution to the DC-SIGN-blocking activity mediated by semen. Clusterin is an enigmatic protein involved in a variety of physiologic and pathologic processes including inflammation, atherosclerosis, and cancer. Our results uncover an unexpected heterogeneity in the glycosylation pattern of clusterin and suggest that the expression of high concentrations of fucose-containing glycans enables semen clusterin to display a unique set of biological functions that might affect the early course of sexually transmitted infectious diseases.


Subject(s)
Cell Adhesion Molecules/metabolism , Clusterin/metabolism , Dendritic Cells/immunology , Dendritic Cells/metabolism , Lectins, C-Type/metabolism , Receptors, Cell Surface/metabolism , Semen/immunology , Semen/metabolism , Adult , Antiviral Agents/blood , Antiviral Agents/metabolism , Cell Adhesion Molecules/blood , Clusterin/blood , Dendritic Cells/virology , Fucose/metabolism , Glycosylation , HIV-1/immunology , HIV-1/metabolism , Humans , Lectins, C-Type/blood , Ligands , Male , Mannose/metabolism , Middle Aged , Protein Binding/immunology , Receptors, Cell Surface/blood , Recombinant Proteins/blood , Recombinant Proteins/metabolism , Semen/virology
12.
Clin Chim Acta ; 548: 117442, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37308048

ABSTRACT

Diagnostic laboratories are an integral part of the research ecosystem in biomedical sciences. Among other roles, laboratories are a source of clinically-characterized samples for research or diagnostic validation studies. Particularly during the COVID-19 pandemic, this process was entered by laboratories with different experience in the ethical management of human samples. The objective of this document is to present the current ethical framework regarding the use of leftover samples in clinical laboratories. Leftover samples are defined as the residue of a sample that has been obtained and used for clinical purposes, and would otherwise be discarded. Secondary use of samples typically demands institutional ethical oversight and informed consent by the participants, although the latter requirement could be exempted when the harm risks are sufficiently small. However, ongoing discussions have proposed that minimal risk is an insufficient argument to allow the use of samples without consent. In this article, we discuss both positions, to finally suggest that laboratories anticipating the secondary use of samples should consider the adoption of broad informed consent, or even the implementation of organized biobanking, in order to achieve higher standards of ethical compliance which would enhance their capacity to fulfill their role in the production of knowledge.


Subject(s)
Biomedical Research , COVID-19 , Humans , Biological Specimen Banks , Laboratories , Ecosystem , Pandemics , COVID-19/diagnosis , COVID-19 Testing
13.
J Extracell Vesicles ; 12(6): e12331, 2023 06.
Article in English | MEDLINE | ID: mdl-37272889

ABSTRACT

Although inflammation is a vital defence response to infection, if left uncontrolled, it can lead to pathology. Macrophages are critical players both in driving the inflammatory response and in the subsequent events required for restoring tissue homeostasis. Extracellular vesicles (EVs) are membrane-enclosed structures released by cells that mediate intercellular communication and are present in all biological fluids, including blood. Herein, we show that extracellular vesicles from plasma (pEVs) play a relevant role in the control of inflammation by counteracting PAMP-induced macrophage activation. Indeed, pEV-treatment of macrophages simultaneously with or prior to PAMP exposure reduced the secretion of pro-inflammatory IL-6 and TNF-α and increased IL-10 response. This anti-inflammatory activity was associated with the promotion of tissue-repair functions in macrophages, characterized by augmented efferocytosis and pro-angiogenic capacity, and increased expression of VEGFa, CD300e, RGS2 and CD93, genes involved in cell growth and tissue remodelling. We also show that simultaneous stimulation of macrophages with a PAMP and pEVs promoted COX2 expression and CREB phosphorylation as well as the accumulation of higher concentrations of PGE2 in cell culture supernatants. Remarkably, the anti-inflammatory activity of pEVs was abolished if cells were treated with a pharmacological inhibitor of COX2, indicating that pEV-mediated induction of COX2 is critical for the pEV-mediated inhibition of inflammation. Finally, we show that pEVs added to monocytes prior to their M-CSF-induced differentiation to macrophages increased efferocytosis and diminished pro-inflammatory cytokine responses to PAMP stimulation. In conclusion, our results suggest that pEVs are endogenous homeostatic modulators of macrophages, activating the PGE2/CREB pathway, decreasing the production of inflammatory cytokines and promoting tissue repair functions.


Subject(s)
Extracellular Vesicles , Humans , Extracellular Vesicles/metabolism , Dinoprostone/analysis , Dinoprostone/metabolism , Cyclooxygenase 2/analysis , Cyclooxygenase 2/metabolism , Macrophages/metabolism , Cytokines/metabolism , Inflammation/metabolism
14.
Front Public Health ; 11: 1095202, 2023.
Article in English | MEDLINE | ID: mdl-36935725

ABSTRACT

Latin America is one of the regions in which the COVID-19 pandemic has a stronger impact, with more than 72 million reported infections and 1.6 million deaths until June 2022. Since this region is ecologically diverse and is affected by enormous social inequalities, efforts to identify genomic patterns of the circulating SARS-CoV-2 genotypes are necessary for the suitable management of the pandemic. To contribute to the genomic surveillance of the SARS-CoV-2 in Latin America, we extended the number of SARS-CoV-2 genomes available from the region by sequencing and analyzing the viral genome from COVID-19 patients from seven countries (Argentina, Brazil, Costa Rica, Colombia, Mexico, Bolivia, and Peru). Subsequently, we analyzed the genomes circulating mainly during 2021 including records from GISAID database from Latin America. A total of 1,534 genome sequences were generated from seven countries, demonstrating the laboratory and bioinformatics capabilities for genomic surveillance of pathogens that have been developed locally. For Latin America, patterns regarding several variants associated with multiple re-introductions, a relatively low percentage of sequenced samples, as well as an increment in the mutation frequency since the beginning of the pandemic, are in line with worldwide data. Besides, some variants of concern (VOC) and variants of interest (VOI) such as Gamma, Mu and Lambda, and at least 83 other lineages have predominated locally with a country-specific enrichments. This work has contributed to the understanding of the dynamics of the pandemic in Latin America as part of the local and international efforts to achieve timely genomic surveillance of SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/epidemiology , Latin America/epidemiology , Pandemics , Genotype
15.
PLoS One ; 16(2): e0247792, 2021.
Article in English | MEDLINE | ID: mdl-33635936

ABSTRACT

Real-time reverse transcription PCR (RT-qPCR) is the gold-standard technique for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection in nasopharyngeal swabs specimens. The analysis by RT-qPCR usually requires a previous extraction step to obtain the purified viral RNA. Unfortunately, RNA extraction constitutes a bottleneck for early detection in many countries since it is expensive, time-consuming and depends on the availability of commercial kits. Here, we describe an extraction-free protocol for SARS-CoV-2 detection by RT-qPCR from nasopharyngeal swab clinical samples in saline solution. The method includes a treatment with proteinase K followed by heat inactivation (PK+HID method). We demonstrate that PK+HID improves the RT-qPCR performance in comparison to the heat-inactivation procedure. Moreover, we show that this extraction-free protocol can be combined with a variety of multiplexing RT-qPCR kits. The method combined with a multiplexing detection kit targeting N and ORF1ab viral genes showed a sensitivity of 0.99 and a specificity of 0.99 from the analysis of 106 positive and 106 negative clinical samples. In conclusion, PK+HID is a robust, fast and inexpensive procedure for extraction-free RT-qPCR determinations of SARS-CoV-2. The National Administration of Drugs, Foods and Medical Devices of Argentina has recently authorized the use of this method.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Endopeptidase K/chemistry , SARS-CoV-2/isolation & purification , Animals , Chlorocebus aethiops , Hot Temperature , Humans , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics , Sensitivity and Specificity , Specimen Handling/methods , Vero Cells
16.
Nat Commun ; 12(1): 5148, 2021 08 26.
Article in English | MEDLINE | ID: mdl-34446714

ABSTRACT

Coronavirus infection in humans is usually associated to respiratory tract illnesses, ranging in severity from mild to life-threatening respiratory failure. The aryl hydrocarbon receptor (AHR) was recently identified as a host factor for Zika and dengue viruses; AHR antagonists boost antiviral immunity, decrease viral titers and ameliorate Zika-induced pathology in vivo. Here we report that AHR is activated by infection with different coronaviruses, potentially impacting antiviral immunity and lung epithelial cells. Indeed, the analysis of single-cell RNA-seq from lung tissue detected increased expression of AHR and AHR transcriptional targets, suggesting AHR signaling activation in SARS-CoV-2-infected epithelial cells from COVID-19 patients. Moreover, we detected an association between AHR expression and viral load in SARS-CoV-2 infected patients. Finally, we found that the pharmacological inhibition of AHR suppressed the replication in vitro of one of the causative agents of the common cold, HCoV-229E, and the causative agent of the COVID-19 pandemic, SARS-CoV-2. Taken together, these findings suggest that AHR activation is a common strategy used by coronaviruses to evade antiviral immunity and promote viral replication, which may also contribute to lung pathology. Future studies should further evaluate the potential of AHR as a target for host-directed antiviral therapy.


Subject(s)
Coronavirus Infections/metabolism , Coronavirus/physiology , Receptors, Aryl Hydrocarbon/metabolism , Signal Transduction , COVID-19/genetics , COVID-19/metabolism , COVID-19/virology , Coronavirus Infections/genetics , Coronavirus Infections/virology , Epithelial Cells/metabolism , Epithelial Cells/virology , Female , Humans , Male , Receptors, Aryl Hydrocarbon/genetics , SARS-CoV-2/physiology
17.
Front Immunol ; 9: 1441, 2018.
Article in English | MEDLINE | ID: mdl-29988364

ABSTRACT

Inflammatory dendritic cells (DCs) are a distinct subset of DCs that derive from circulating monocytes infiltrating injured tissues. Monocytes can differentiate into DCs with different functional signatures, depending on the presence of environment stimuli. Among these stimuli, transforming growth factor-beta (TGF-ß) and prostaglandin E2 (PGE2) have been shown to modulate the differentiation of monocytes into DCs with different phenotypes and functional profiles. In fact, both mediators lead to contrasting outcomes regarding the production of inflammatory and anti-inflammatory cytokines. Previously, we have shown that human semen, which contains high concentrations of PGE2, promoted the differentiation of DCs into a tolerogenic profile through a mechanism dependent on signaling by E-prostanoid receptors 2 and 4. Notably, this effect was induced despite the huge concentration of TGF-ß present in semen, suggesting that PGE2 overrides the influence exerted by TGF-ß. No previous studies have analyzed the joint actions induced by PGE2 and TGF-ß on the function of monocytes or DCs. Here, we analyzed the phenotype and functional profile of monocyte-derived DCs differentiated in the presence of TGF-ß and PGE2. DC differentiation guided by TGF-ß alone enhanced the expression of CD1a and abrogated LPS-induced expression of IL-10, while differentiation in the presence of PGE2 impaired CD1a expression, preserved CD14 expression, abrogated IL-12 and IL-23 production, stimulated IL-10 production, and promoted the expansion of FoxP3+ regulatory T cells in a mixed lymphocyte reaction. Interestingly, DCs differentiated in the presence of TGF-ß and PGE2 showed a phenotype and functional profile closely resembling those induced by PGE2 alone. Finally, we found that PGE2 inhibited TGF-ß signaling through an action exerted by EP2 and EP4 receptors coupled to cyclic AMP increase and protein kinase A activity. These results indicate that PGE2 suppresses the influence exerted by TGF-ß during DC differentiation, imprinting a tolerogenic signature. High concentrations of TGF-ß and PGE2 are usually found in infectious, autoimmune, and neoplastic diseases. Our observations suggest that in these scenarios PGE2 might play a mandatory role in the acquisition of a regulatory profile by DCs.

18.
J Neurochem ; 103(5): 2047-57, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17868301

ABSTRACT

Alterations in brain serotonin levels are implicated in major depression and are regulated by tryptophan hydroxylase-2 (TPH2). To study its regulation, we measured TPH2 RNA by quantitative RT-PCR in differentiated serotonergic rat raphe RN46A and GH4C1 pituitary cells, which express TPH2. Upon calcium mobilization using KCl (40 mmol/L), TPH2 RNA was rapidly (1 h) and strongly (> 10-fold) induced in differentiated RN46A cells, but not in GH4C1 cells. This effect was blocked by actinomycin D, implicating transcriptional activation. Similarly, calcium ionophore ionomycin induced TPH2 RNA by threefold in RN46A cells. To address the promoter sites involved, the transcription start site was identified and a series of TATA-containing TPH2 promoter-luciferase constructs were analyzed. In differentiated RN46A cells, the TPH2 promoter was induced 2.5-fold by ionomycin, similar to its action on TPH2 RNA. By contrast, ionomycin had no effect on TPH2 promoter activity in GH4C1 cells or TPH2-negative L6 myoblasts. Ionomycin sensitivity was localized to within 88 bp of the start site, containing putative CCATT-enhancer binding protein element, activator protein-1 and -2 (AP-1, AP-2) elements. These results are the first to identify calcium-mediated regulation of the proximal TPH2 promoter as critical for cell-specific TPH2 expression.


Subject(s)
Calcium/metabolism , Gene Expression Regulation , Neurons/enzymology , Transcriptional Activation/physiology , Tryptophan Hydroxylase/metabolism , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Humans , Ionomycin/pharmacology , Ionophores/pharmacology , Luciferases/biosynthesis , Mutation/physiology , Neurons/drug effects , Promoter Regions, Genetic/physiology , RNA, Messenger/biosynthesis , Raphe Nuclei/cytology , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction/methods , Sequence Alignment , Transfection , Tryptophan Hydroxylase/genetics
19.
J Neurosci Methods ; 164(1): 59-67, 2007 Aug 15.
Article in English | MEDLINE | ID: mdl-17498810

ABSTRACT

Previous reports establishing raphe cultures typically yield less than 1% serotonin (5-HT)-positive neurons and are impractical for transcriptional studies. In this study, we have established primary cultures enriched in 5-HT neurons and quantified the proportion of cells expressing serotonergic and non-serotonergic markers. We have also shown the feasibility of using the multiplex real-time PCR technique to measure the relative amounts of RNA for some of these markers. Rostral raphe cells derived from E13-15 rat embryos were cultured for 7 days and analyzed by quantitative immunofluorescence and western blot analysis. In these cultures, approximately 8% of neurons were immunopositive for serotonergic markers (5-HT or tryptophan hydroxylase (TPH)). The percentage of cells labeled for GFAP (glial marker), tyrosine hydroxylase (catecholaminergic), and GAD65/67 (GABAergic) was 5, 1, and 54%, respectively. Transcription factors REST/NRSF and Deaf-1 were present in 9 and 98% of cells, respectively. Multiplex quantitative RT-PCR (Q-PCR) analysis was done for TPH2, 5-HT1A receptor or Deaf-1 RNAs paired with GAPDH RNA as control. Using this approach, standard curves for each RNA were obtained over 200-fold concentration range of dilution with r2 values >0.99. The relative abundances determined by Q-PCR are consistent with the expression of TPH2>Deaf-1>5-HT1A receptor RNA in serotonergic raphe cells. The standard error of TPH2 RNA levels between cultures was <20%, indicating a consistent purity of 5-HT neurons. Thus, we have generated a highly consistent and reproducible model system that is enriched in 5-HT neurons and that will be valuable in future investigation of serotonergic regulation.


Subject(s)
Neurochemistry/methods , Neurons/chemistry , RNA, Messenger/analysis , Raphe Nuclei/chemistry , Reverse Transcriptase Polymerase Chain Reaction/methods , Serotonin/analysis , Animals , Biomarkers/analysis , Biomarkers/metabolism , Cell Culture Techniques , Cell Differentiation/physiology , Cells, Cultured , Gene Expression Regulation, Developmental/genetics , Neurons/metabolism , Nuclear Proteins/genetics , RNA, Messenger/metabolism , Raphe Nuclei/cytology , Raphe Nuclei/metabolism , Rats , Receptor, Serotonin, 5-HT1A/genetics , Reproducibility of Results , Serotonin/metabolism , Transcription Factors/analysis , Transcription Factors/metabolism , Tryptophan Hydroxylase/genetics , Tryptophan Hydroxylase/metabolism
20.
Rev. esp. med. legal ; 48(1): 17-21, Enero - Marzo 2022.
Article in Spanish | IBECS (Spain) | ID: ibc-206857

ABSTRACT

A partir de la emergencia del SARS-CoV-2 en el mundo se desató la pandemia por COVID-19 que afectó a 185 países; aparecieron numerosas publicaciones científicas presentando datos epidemiológicos, clínicos, estadísticos y microbiológicos. La elevada mortalidad ha implicado la necesidad de contar con datos cada vez más precisos con relación al virus y a su comportamiento en el medio y, por otro lado, enfrentó a los equipos de salud con un grave problema con relación al manejo seguro de cadáveres y a los riesgos de transmisión que ello implica. El objetivo del presente estudio ha sido detectar la presencia de ARN del SARS-CoV-2 en cadáveres remitidos a la Morgue Judicial de la Nación que no estuvieran comprendidos en la definición de caso sospechoso propuesta por el Ministerio de Salud de la Nación de la República Argentina. Se realizaron hisopados nasofaríngeos a 101 cadáveres elegidos aleatoriamente y basándose en criterios de inclusión para la detección de ARN viral mediante técnica RT-PCR. Se detectó ARN viral en el 16,8% de los cadáveres incluidos en el estudio. (AU)


Following the emergence of SARS-CoV-2 in the world, the COVID-19 pandemic broke out, affecting 185 countries. There have been numerous scientific publications presenting epidemiological, clinical, statistical, and microbiological data. The high mortality has implied the need for increasingly accurate data regarding the virus and its behaviour in the environment and, on the other hand, faced health teams with a serious problem in relation to the safe handling of corpses and the risks of transmission that this implies. The objective of this study was to detect the presence of SARS-CoV-2 RNA in corpses sent to the National Judicial Morgue that were not included in the definition of a suspected case submitted by the Argentine Ministry of Health. Nasopharyngeal and oropharyngeal swabs were taken from 101 cadavers chosen randomly and based on inclusion criteria for detection of viral RNA using the RT-PCR technique. Of the cadavers included in the study, 16.8%, not classified as suspected cases of COVID-19, were tested for the presence of viral RNA in the samples collected. (AU)


Subject(s)
Humans , Coronavirus Infections/epidemiology , Coronavirus Infections/mortality , Pandemics/statistics & numerical data , Autopsy , Polymerase Chain Reaction , Argentina
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