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1.
Cancer Res Commun ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747616

RESUMO

Neoadjuvant chemotherapy (NAC) is linked with clinical advantages in urothelial carcinoma for patients with muscle-invasive bladder cancer (MIBC). Despite comprehensive research into the influence of tumor mutation expression profiles and clinicopathological factors on chemotherapy response, the role of the gut microbiome (GM) in bladder cancer(BC) chemotherapy response remains poorly understood. This study examines the variance in the gut microbiome(GM) of BC patients compared to healthy adults, and investigates GM compositional differences between patients who respond to chemotherapy versus those who exhibit residual disease. Our study reveals distinct clustering, effectively separating the BC and healthy cohorts. However, no significant differences were observed between chemotherapy responders and non-responders within community subgroups. Machine Learning models based on responder status outperformed clinical variables in predicting complete response (AUC 0.88 vs AUC 0.50), although no single microbial species emerged as a fully reliable biomarker. The evaluation of short-chain fatty acid (SCFA) concentration in blood and stool revealed no correlation with responder status. Still, SCFA analysis showed a higher abundance of Akkermansia (rs = 0.51, p = 0.017) and Clostridia (rs = 0.52, p = 0.018), which correlated with increased levels of detectable fecal isobutyric acid. Higher levels of fecal Lactobacillus (rs = 0.49, p=0.02) and Enterobacteriaceae (rs = 0.52, p < 0.03) correlated with increased fecal propionic acid. In conclusion, our study constitutes the first large-scale, multi-center assessment of GM composition, suggesting the potential for a complex microbial signature to predict patients more likely to respond to NAC based on multiple taxa.

2.
Eur Urol Oncol ; 6(2): 190-203, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36868921

RESUMO

BACKGROUND: The application of next-generation sequencing techniques has enabled characterization of urinary tract microbiome. Although many studies have demonstrated associations between the human microbiome and bladder cancer (BC), these have not always reported consistent results, thereby necessitating cross-study comparisons. Thus, the fundamental questions remain how we can utilize this knowledge. OBJECTIVE: The aim of our study was to examine the disease-associated changes in urine microbiome communities globally utilizing a machine learning algorithm. DESIGN, SETTING, AND PARTICIPANTS: Raw FASTQ files were downloaded for the three published studies in urinary microbiome in BC patients, in addition to our own prospectively collected cohort. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Demultiplexing and classification were performed using the QIIME 2020.8 platform. De novo operational taxonomic units were clustered using the uCLUST algorithm and defined by 97% sequence similarity and classified at the phylum level against the Silva RNA sequence database. The metadata available from the three studies included were used to evaluate the differential abundance between BC patients and controls via a random-effect meta-analysis using the metagen R function. A machine learning analysis was performed using the SIAMCAT R package. RESULTS AND LIMITATIONS: Our study includes 129 BC urine and 60 healthy control samples across four different countries. We identified a total of 97/548 genera to be differentially abundant in the BC urine microbiome compared with that of healthy patients. Overall, while the differences in diversity metrics were clustered around the country of origin (Kruskal-Wallis, p < 0.001), collection methodology was a driver of microbiome composition. When assessing dataset from China, Hungary, and Croatia, data demonstrated no discrimination capacity to distinguish between BC patients and healthy adults (area under the curve [AUC] 0.577). However, inclusion of samples with catheterized urine improved the diagnostic accuracy of prediction for BC to AUC 0.995, with precision-recall AUC = 0.994. Through elimination of contaminants associated with the collection methodology among all cohorts, our study identified increased abundance of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria Sphingomonas, Acinetobacter, Micrococcus, Pseudomonas, and Ralstonia to be consistently present in BC patients. CONCLUSIONS: The microbiota of the BC population may be a reflection of PAH exposure from smoking, environmental pollutants, and ingestion. Presence of PAHs in the urine of BC patients may allow for a unique metabolic niche and provide necessary metabolic resources where other bacteria are not able to flourish. Furthermore, we found that while compositional differences are associated with geography more than with disease, many are driven by the collection methodology. PATIENT SUMMARY: The goal of our study was to compare the urine microbiome of bladder cancer patients with that of healthy controls and evaluate any potential bacteria that may be more likely to be found in patients with bladder cancer. Our study is unique as it evaluates this across multiple countries, to find a common pattern. After we removed some of the contamination, we were able to localize several key bacteria that are more likely to be found in the urine of bladder cancer patients. These bacteria all share their ability to break down tobacco carcinogens.


Assuntos
Microbiota , Neoplasias da Bexiga Urinária , Adulto , Humanos , Bactérias/genética , Neoplasias da Bexiga Urinária/urina , Microbiota/genética , Motivação , RNA Ribossômico 16S/genética
3.
bioRxiv ; 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36747848

RESUMO

Treatment with neoadjuvant chemotherapy (NAC) in muscle invasive bladder cancer (MIBC) is associated with clinical benefit in urothelial carcinoma. While extensive research evaluating role of tumor mutational expression profiles and clinicopathologic factors into chemoresponse has been published, the role of gut microbiome (GM) in bladder cancer in chemoresponse has not been thoroughly evaluated. A working knowledge of the microbiome and its effect on all forms of cancer therapy in BC is critical. Here we examine gut microbiome of bladder cancer patients undergoing NAC. Overall, there was no significant difference in alpha and beta diversity by responder status. However, analysis of fecal microbiome samples showed that a higher abundance of Bacteroides within both institutional cohorts during NAC was associated with residual disease at the time of radical cystectomy regardless of chemotherapy regimen. Group community analysis revealed presence of favorable microbial subtypes in complete responders. Finally, fecal microbial composition outperformed clinical variables in prediction of complete response (AUC 0.88 vs AUC 0.50), however, no single microbial species could be regarded as a fully consistent biomarker. Microbiome-based community signature as compared to single microbial species is more likely to be associated as the link between bacterial composition and NAC response.

4.
Eur Urol Open Sci ; 43: 5-13, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36353067

RESUMO

Background: Until recently, the properties of microbiome and mycobiome in humans and its relevance to disease have largely been unexplored. While the interest of microbiome and malignancy over the past few years have burgeoned with advent of new technologies, no research describing the composition of mycobiome in bladder cancer has been done. Deciphering of the metagenome and its aggregate genetic information can be used to understand the functional properties and relationships between the bacteria, fungi, and cancer. Objective: The aim of this project is to characterize the compositional range of the normal versus bladder cancer mycobiome of the gut. Design setting and participants: An internal transcribed spacer (ITS) survey of 52 fecal samples was performed to evaluate the gut mycobiome differences between noncancer controls and bladder cancer patients. Outcome measurements and statistical analysis: Our study evaluated the differences in mycobiome among patients with bladder cancer, versus matched controls. Our secondary analysis evaluated compositional differences in the gut as a function of response status with neoadjuvant chemotherapy. Data demultiplexing and classification were performed using the QIIME v.1.1.1.1 platform. The Ion Torrent-generated fungal ITS sequence data were processed using QIIME (v.1.9.1), and the reads were demultiplexed, quality filtered, and clustered into operation taxonomic units using default parameters. Alpha and beta diversity were computed and plotted in Phyloseq, principal coordinate analysis was performed on Bray-Curtis dissimilarity indices, and a one-way permutational multivariate analysis of variance was used to test for significant differences between cohorts. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was applied to infer functional categories associated with taxonomic composition. Results and limitations: We found distinctive mycobiome differences between control group (n = 32) and bladder cancer (n = 29) gut flora, and identified an increasing abundance of Tremellales, Hypocreales, and Dothideales. Significant differences in alpha and beta diversity were present between the groups (control vs bladder; p = 0.002), noting distinct compositions within each cohort. A subgroup analysis by sex and neoadjuvant chemotherapy status did not show any further differences in mycobiome composition and diversity. Our results indicate that the gut mycobiome may modulate tumor response to preoperative chemotherapy in bladder cancer patients. We propose that patients with a "favorable" mycobiome composition (eg, high diversity, and low abundance of Agaricomycetes and Saccharomycetes) may have enhanced systemic immune response to chemotherapy through antigen presentation. Conclusions: Our study is the first to characterize the enteric mycobiome in patients with bladder cancer and describe complex ecological network alterations, indicating complex bacteria-fungi interactions, particularly highlighted among patients with complete neoadjuvant chemotherapy response. Patient summary: Our study has demonstrated that the composition of stool mycobiome (fungal inhabitants of the gastrointestinal tract) in patients with bladder cancer is different from that in noncancer individuals. Furthermore, when evaluating how patients respond to chemotherapy given prior to their surgery, our study noted significant differences between patients who responded and those who did not.

5.
Haematologica ; 107(12): 2928-2943, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35615924

RESUMO

Adult T-cell leukemia and lymphoma (ATLL) is an intractable T-cell neoplasia caused by a retrovirus, namely human T-cell leukemia virus type 1 (HTLV-1). Patients suffering from ATLL present a poor prognosis and have a dearth of treatment options. In contrast to the sporadic expression of viral transactivator protein Tax present at the 5' promoter region long terminal repeats (LTR), HTLV-1 bZIP gene (HBZ) is encoded by 3'LTR (the antisense promoter) and maintains its constant expression in ATLL cells and patients. The antisense promoter is associated with selective retroviral gene expression and has been an understudied phenomenon. Herein, we delineate the activity of transcription factor MEF (myocyte enhancer factor)-2 family members, which were found to be enriched at the 3'LTR and play an important role in the pathogenesis of ATLL. Of the four MEF isoforms (A to D), MEF-2A and 2C were highly overexpressed in a wide array of ATLL cell lines and in acute ATLL patients. The activity of MEF-2 isoforms were determined by knockdown experiments that led to decreased cell proliferation and regulated cell cycle progression. High enrichment of MEF-2C was observed at the 3'LTR along with cofactors Menin and JunD resulting in binding of MEF-2C to HBZ at this region. Chemical inhibition of MEF-2 proteins resulted in the cytotoxicity of ATLL cells in vitro and reduction of proviral load in a humanized mouse model. Taken together, this study provides a novel mechanism of 3'LTR regulation and establishes MEF-2 signaling a potential target for therapeutic intervention for ATLL.


Assuntos
Vírus Linfotrópico T Tipo 1 Humano , Leucemia-Linfoma de Células T do Adulto , Linfoma , Animais , Humanos , Camundongos , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Leucemia-Linfoma de Células T do Adulto/patologia , Linfoma/genética , Fatores de Transcrição MEF2/genética , Fatores de Transcrição MEF2/metabolismo , Regiões Promotoras Genéticas , Proteínas Virais/genética , Proteínas Virais/metabolismo
6.
J Neuroimmune Pharmacol ; 16(2): 403-424, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32607691

RESUMO

Neuroinflammation leads to tissue injury causing many of the clinical symptoms of Multiple Sclerosis, an autoimmune disorder of the central nervous system (CNS). While T cells, specifically Th1 and Th17 cells, are the ultimate effectors of this disease, dendritic cells (DCs) mediate T cell polarization, activation, etc. In our previous study, Apigenin, a natural flavonoid, has been shown to reduce EAE disease severity through amelioration of demyelination in the CNS as well as the sequestering of DCs and other myeloid cells in the periphery. Here, we show that Apigenin exerts its effects possibly through shifting DC modulated T cell responses from Th1 and Th17 type towards Treg directed responses evident through the decrease in T-bet, IFN-γ (Th1), IL-17 (Th17) and increase in IL-10, TGF-ß and FoxP3 (Treg) expression in cells from both normal human donors and EAE mice. RelB, an NF-κß pathway protein is central to DC maturation, its antigen presentation capabilities and DC-mediated T cell activation. Apigenin reduced mRNA and protein levels of RelB and also reduced its nuclear translocation. Additionally, siRNA-mediated silencing of RelB further potentiated the RelB-mediated effects of Apigenin thus confirming its role in Apigenin directed regulation of DC biology. These results provide key information about the molecular events controlled by Apigenin in its regulation of DC activity marking its potential as a therapy for neuroinflammatory disease. Graphical Abstract.


Assuntos
Apigenina/farmacologia , Células Dendríticas/efeitos dos fármacos , Inflamação/imunologia , Ativação Linfocitária/efeitos dos fármacos , Fator de Transcrição RelB/metabolismo , Animais , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Encefalomielite Autoimune Experimental/imunologia , Humanos , Inflamação/metabolismo , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/imunologia , Fator de Transcrição RelB/efeitos dos fármacos
7.
Antioxidants (Basel) ; 8(2)2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30764536

RESUMO

Inflammation has been reported to be intimately linked to the development or worsening of several non-infectious diseases. A number of chronic conditions such as cancer, diabetes, cardiovascular disorders, autoimmune diseases, and neurodegenerative disorders emerge as a result of tissue injury and genomic changes induced by constant low-grade inflammation in and around the affected tissue or organ. The existing therapies for most of these chronic conditions sometimes leave more debilitating effects than the disease itself, warranting the advent of safer, less toxic, and more cost-effective therapeutic alternatives for the patients. For centuries, flavonoids and their preparations have been used to treat various human illnesses, and their continual use has persevered throughout the ages. This review focuses on the anti-inflammatory actions of flavonoids against chronic illnesses such as cancer, diabetes, cardiovascular diseases, and neuroinflammation with a special focus on apigenin, a relatively less toxic and non-mutagenic flavonoid with remarkable pharmacodynamics. Additionally, inflammation in the central nervous system (CNS) due to diseases such as multiple sclerosis (MS) gives ready access to circulating lymphocytes, monocytes/macrophages, and dendritic cells (DCs), causing edema, further inflammation, and demyelination. As the dearth of safe anti-inflammatory therapies is dire in the case of CNS-related disorders, we reviewed the neuroprotective actions of apigenin and other flavonoids. Existing epidemiological and pre-clinical studies present considerable evidence in favor of developing apigenin as a natural alternative therapy against chronic inflammatory conditions.

8.
Vaccine ; 36(33): 5046-5057, 2018 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-30005946

RESUMO

Human T-cell leukemia virus type 1 (HTLV-1) has infected as many as 10 million people worldwide. While 90% are asymptomatic, 5% develop severe diseases including adult T-cell leukemia/lymphoka (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). No vaccine against HTLV-1 exists, and screening programs are not universal. However, patients with chronic HTLV-1 infection have high frequencies of HTLV-1-activated CD8+ T cells, and the two main HLA alleles (A2, A24) are present in 88% of infected individuals. We thus utilized an immunoproteomics approach to characterize MHC-I restricted epitopes presented by HLA-A2+, A24+ MT-2 and SLB-1 cell lines. Unlike traditional motif prediction algorithms, this approach identifies epitopes associated with cytotoxic T-cell responses in their naturally processed forms, minimizing differences in antigen processing and protein expression levels. Out of nine identified peptides, we confirmed six novel MHC-I restricted epitopes that were capable of binding HLA-A2 and HLA-A24 alleles and used in vitro and in vivo methods to generate CD8+ T cells specific for each of these peptides. MagPix MILLIPLEX data showed that in vitro generated epitope-specific CD8+ T cells secreted IFN-É£, granzyme B, MIP-1α, TNF-α, perforin and IL-10 when cultured in the presence of MT-2 cell line. Degranulation assay confirmed cytotoxic response through surface expression of CD107 on CD8+ T cells when cultured with MT-2 cells. A CD8+ T-cell killing assay indicated significant antiviral activity of CD8+ T cells specific against all identified peptides. In vivo generated CD8+ T cells similarly demonstrated immunogenicity on ELISpot, CD107 degranulation assay, and MagPix MILLIPLEX analysis. These epitopes are thus candidates for a therapeutic peptide-based vaccine against HTLV-1, and our results provide preclinical data for the advancement of such a vaccine.


Assuntos
Genes MHC Classe I/imunologia , Infecções por HTLV-I/prevenção & controle , Infecções por HTLV-I/virologia , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Vírus Linfotrópico T Tipo 1 Humano/patogenicidade , Animais , Linhagem Celular , Linhagem Celular Tumoral , Epitopos/imunologia , Feminino , Citometria de Fluxo , Infecções por HTLV-I/imunologia , Células Hep G2 , Humanos , Espectrometria de Massas , Camundongos , Camundongos Transgênicos
9.
Sci Rep ; 7(1): 2707, 2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28578388

RESUMO

The mechanism of dendritic cells (DCs) recruitment across the blood brain barrier (BBB) during neuroinflammation has been the least explored amongst all leukocytes. For cells of myeloid origin, while integrins function at the level of adhesion, the importance of lectins remains unknown. Here, we identified functions of one C-type lectin receptor, CLEC12A, in facilitating DC binding and transmigration across the BBB in response to CCL2 chemotaxis. To test function of CLEC12A in an animal model of multiple sclerosis (MS), we administered blocking antibody to CLEC12A that significantly ameliorated disease scores in MOG35-55-induced progressive, as well as PLP138-151-induced relapsing-remitting experimental autoimmune encephalomyelitis (EAE) mice. The decline in both progression and relapse of EAE occurred as a result of reduced demyelination and myeloid cell infiltration into the CNS tissue. DC numbers were restored in the spleen of C57BL/6 and peripheral blood of SJL/J mice along with a decreased TH17 phenotype within CD4+ T-cells. The effects of CLEC12A blocking were further validated using CLEC12A knockout (KO) animals wherein EAE disease induction was delayed and reduced disease severity was observed. These studies reveal the utility of a DC-specific mechanism in designing new therapeutics for MS.


Assuntos
Anticorpos Bloqueadores/farmacologia , Encefalomielite Autoimune Experimental/etiologia , Encefalomielite Autoimune Experimental/metabolismo , Imunidade/efeitos dos fármacos , Lectinas Tipo C/antagonistas & inibidores , Células Mieloides/imunologia , Células Mieloides/metabolismo , Receptores Mitogênicos/antagonistas & inibidores , Animais , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Quimiocina CCL2/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Encefalomielite Autoimune Experimental/diagnóstico , Encefalomielite Autoimune Experimental/tratamento farmacológico , Endotélio Vascular/metabolismo , Imunidade/genética , Lectinas/genética , Lectinas/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Camundongos , Camundongos Knockout , Modelos Biológicos , Células Mieloides/efeitos dos fármacos , Fenótipo , Ligação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Receptores Mitogênicos/genética , Recidiva , Índice de Gravidade de Doença , Transdução de Sinais , Migração Transendotelial e Transepitelial
10.
J Neuroimmune Pharmacol ; 12(3): 504-520, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28374110

RESUMO

To date, the lack of a suitable small animal model has hindered our understanding of Human T-cell lymphotropic virus (HTLV)-1 chronic infection and associated neuropathogenesis defined as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The host immune response plays a critical role in the outcome of HTLV-1 infection, which could be better tested in the context of humanized (hu) mice. Thus, we employ here the Balb/c-Rag1-/-γc-/- or Rag1 as well as Bone marrow-Liver-Thymic (BLT) mouse models for engraftment of human CD34+ hematopoietic stem cells. Flow cytometry and histological analyses confirmed reconstitution of Rag1 and BLT mice with human immune cells. Following HTLV-1 infection, proviral load (PVL) was detected in the blood of Rag-1 and BLT hu-mice as early as 2 weeks post-infection (wpi) with sustained elevation in the subsequent weeks followed by Tax expression. Additionally, infection was compared between adult and neonatal Rag1 mice with both PVL and Tax expression considerably higher in the adult Rag1 mice as compared to the neonates. Establishment of peripheral infection led to lymphocytic infiltration with concomitant Tax expression and resulting myelin disruption within the central nervous system of infected mice. In addition, up-regulation in the expression of several immune checkpoint mediators such as programmed cell death-1 (PD-1), T-cell Ig and ITIM domain (TIGIT), and T cell Ig and mucin domain-3 protein (Tim-3) were observed on CD8+ T cells in various organs including the CNS of infected hu-mice. Collectively, these studies represent the first attempt to establish HTLV-1 neuropathogenesis in the context of Rag-1 and BLT hu-mice as potential novel tools for understanding HTLV-1 neuropathogenesis and testing of novel therapies such as immune checkpoint blockade in the amelioration of chronic HTLV-1 infection.


Assuntos
Modelos Animais de Doenças , Infecções por HTLV-I , Animais , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout
11.
J Neuroimmune Pharmacol ; 11(1): 36-47, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26040501

RESUMO

Apigenin, a natural flavonoid, found in several plants, fruits, vegetables, herbs, and spices, is known to have anti-oxidant and anti-inflammatory properties that are evident in the use of these substances for centuries as medicinal approaches to treat asthma, insomnia, Parkinson's disease, neuralgia, and shingles. However, there is a considerable dearth of information regarding its effect on immune cells, especially dendritic cells (DC) that maintain the critical balance between an immunogenic and tolerogenic immune response, in an immunospecialized location like the central nervous system (CNS). In this paper we looked at the anti-inflammatory properties of Apigenin in restoration of immune function and the resultant decrease in neuroinflammation. In vivo, a significant reduction in severity of experimental autoimmune encephalomyelitis (EAE) progression and relapse was observed in C57BL/6 (progressive) and SJL/J (relapse-remitting) mouse models of multiple sclerosis upon treatment with Apigenin. Apigenin treated EAE mice show decreased expression of α4 integrin and CLEC12A on splenic DCs and an increased retention of immune cells in the periphery compared to untreated EAE mice. This correlated consequently with immunohistochemistry findings of decreased immune cell infiltration and reduced demyelination in the CNS. These results indicate a protective role of Apigenin against the neurodegenerative effects resulting from the entry of DC stimulated pathogenic T cells into the CNS thus implicating a potential therapy for neuroinflammatory disease.


Assuntos
Anti-Inflamatórios/farmacologia , Apigenina/farmacologia , Células Dendríticas/efeitos dos fármacos , Encefalomielite Autoimune Experimental/patologia , Animais , Encéfalo/imunologia , Encéfalo/patologia , Células Dendríticas/imunologia , Encefalomielite Autoimune Experimental/imunologia , Feminino , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Medula Espinal/imunologia , Medula Espinal/patologia
12.
J Interferon Cytokine Res ; 35(9): 698-709, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26090579

RESUMO

Although interferon (IFN)-α is known to exert immunomodulatory and antiproliferative effects on dendritic cells (DCs) through induction of protein-coding IFN-stimulated genes (ISGs), little is known about IFN-α-regulated miRNAs in DCs. Since several miRNAs are involved in regulating DC functions, it is important to investigate whether IFN-α's effects on DCs are mediated through miRNAs as well. In this study, we examined miRNA expression patterns in myeloid DCs (mDCs) and plasmacytoid DCs after exposing them to IFN-α. We report that IFN-α downregulates miR-221 in both DC subsets via inhibition of STAT3. We validated proapoptotic proteins BCL2L11 and CDKN1C as miR-221 targets suggesting that IFN-α can induce DC apoptosis via miR-221 downregulation. In addition, we validated another miR-221 target, SOCS1, which is known to be a negative regulator of JAK/STAT signaling. Consistent with this, miR-221 overexpression in mDCs enhanced the secretion of proinflammatory cytokines IL-6 and TNF-α. In peripheral blood mononuclear cells (PBMCs) of HIV-1/HCV co-infected individuals undergoing IFN-α-based treatment the baseline miR-221 expression was lower in non-responders compared with responders; and miR-221 expression directly correlated with DC frequency and IL-6/TNF-α secretion. In addition to PBMCs, we isolated total liver cells and kupffer cells from HCV-infected individuals and individuals with alcoholic cirrhosis. We found that both total liver cells and kupffer cells from HCV-infected individuals had significantly higher miR-221 levels compared with individuals with cirrhosis. Overall, we demonstrate that IFN-α exerts both antiproliferative and immunomodulatory effects on mDCs via miR-221 downregulation; and IFN-miR-221 axis can play important role in HCV pathogenesis and treatment.


Assuntos
Células Dendríticas/metabolismo , Células Dendríticas/virologia , Regulação para Baixo/genética , Hepacivirus/patogenicidade , Interferon-alfa/metabolismo , MicroRNAs/genética , Apoptose/fisiologia , Infecções por HIV/genética , Infecções por HIV/metabolismo , Infecções por HIV/virologia , HIV-1/patogenicidade , Hepatite C/genética , Hepatite C/metabolismo , Hepatite C/virologia , Hepatócitos/metabolismo , Hepatócitos/virologia , Humanos , Interleucina-6/metabolismo , Janus Quinases/metabolismo , Células de Kupffer/metabolismo , Células de Kupffer/virologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Fígado/metabolismo , Fígado/virologia , Cirrose Hepática Alcoólica/genética , Cirrose Hepática Alcoólica/metabolismo , Cirrose Hepática Alcoólica/virologia , Fator de Transcrição STAT3/metabolismo , Proteína 1 Supressora da Sinalização de Citocina , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
13.
Retrovirology ; 12: 23, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25809782

RESUMO

BACKGROUND: The exact molecular mechanisms regarding HTLV-1 Tax-mediated viral gene expression and CD4 T-cell transformation have yet to be fully delineated. Herein, utilizing virus-infected primary CD4+ T cells and the virus-producing cell line, MT-2, we describe the involvement and regulation of Myocyte enhancer factor-2 (specifically MEF-2A) during the course of HTLV-1 infection and associated disease syndrome. RESULTS: Inhibition of MEF-2 expression by shRNA and its activity by HDAC9 led to reduced viral replication and T-cell transformation in correlation with a heightened expression of MEF-2 in ATL patients. Mechanistically, MEF-2 was recruited to the viral promoter (LTR, long terminal repeat) in the context of chromatin, and constituted Tax/CREB transcriptional complex via direct binding to the HTLV-1 LTR. Furthermore, an increase in MEF-2 expression was observed upon infection in an extent similar to CREB (known Tax-interacting transcription factor), and HATs (p300, CBP, and p/CAF). Confocal imaging confirmed MEF-2 co-localization with Tax and these proteins were also shown to interact by co-immunoprecipitation. MEF-2 stabilization of Tax/CREB complex was confirmed by a novel promoter-binding assay that highlighted the involvement of NFAT (nuclear factor of activated T cells) in this process via Tax-mediated activation of calcineurin (a calcium-dependent serine-threonine phosphatase). MEF-2-integrated signaling pathways (PI3K/Akt, NF-κB, MAPK, JAK/STAT, and TGF-ß) were also activated during HTLV-1 infection of primary CD4+ T cells, possibly regulating MEF-2 activity. CONCLUSIONS: We demonstrate the involvement of MEF-2 in Tax-mediated LTR activation, viral replication, and T-cell transformation in correlation with its heightened expression in ATL patients through direct binding to DNA within the HTLV-1 LTR.


Assuntos
Linfócitos T CD4-Positivos/virologia , Transformação Celular Viral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Produtos do Gene tax/metabolismo , Interações Hospedeiro-Patógeno , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Linfócitos T CD4-Positivos/fisiologia , Células Cultivadas , Humanos , Fatores de Transcrição MEF2/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Multimerização Proteica , Transcrição Gênica , Replicação Viral
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