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1.
J Med Virol ; 95(4): e28688, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36946498

RESUMO

Viral metagenomics has been extensively applied for the identification of emerging or poorly characterized viruses. In this study, we applied metagenomics for the identification of viral infections among pediatric patients with acute respiratory disease, but who tested negative for SARS-CoV-2. Twelve pools composed of eight nasopharyngeal specimens were submitted to viral metagenomics. Surprisingly, in two of the pools, we identified reads belonging to the poorly characterized Malawi polyomavirus (MWPyV). Then, the samples composing the positive pools were individually tested using quantitative polymerase chain reaction for identification of the MWPyV index cases. MWPyV-positive samples were also submitted to respiratory virus panel testing due to the metagenomic identification of different clinically important viruses. Of note, MWPyV-positive samples tested also positive for respiratory syncytial virus types A and B. In this study, we retrieved two complete MWPyV genome sequences from the index samples that were submitted to phylogenetic inference to investigate their viral origin. Our study represents the first molecular and genomic characterization of MWPyV obtained from pediatric patients in South America. The detection of MWPyV in acutely infected infants suggests that this virus might participate (coparticipate) in cases of respiratory symptoms. Nevertheless, future studies based on testing of a larger number of clinical samples and MWPyV complete genomes appear to be necessary to elucidate if this emerging polyomavirus might be clinically important.


Assuntos
COVID-19 , Infecções por Polyomavirus , Polyomavirus , Infecções Respiratórias , Vírus , Lactente , Criança , Humanos , Metagenômica , Brasil/epidemiologia , Malaui/epidemiologia , Filogenia , SARS-CoV-2 , Infecções por Polyomavirus/epidemiologia , Polyomavirus/genética , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia
2.
Transfus Clin Biol ; 30(1): 143-146, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36306977

RESUMO

Merkel cell polyomavirus (MCPyV) is an oncogenic virus that has been etiologically linked to Merkel cell carcinoma. Low levels of MCPyV DNA have been detected in blood donors with unclear impact on transfusion. The prevalence of MCPyV DNA in Brazilian blood donors is unclear. Therefore, the objective of this study was to evaluate the MCPyV DNA prevalence among Brazilian blood donors. We examined the presence of MCPyV DNA by real-time PCR (qPCR) in a total of 450 serum samples obtained from blood donors from three Brazilian regions (North, Central-West and South). The overall estimated MCPyV DNA prevalence was 1.1% (CI = 95%, 0.16-2.06%). Divided by region, in North Brazil (city of Macapa, state of Amapá) and South Brazil (city of Santa Maria, state of Rio Grande do Sul), the MCPyV prevalence was the same: 1.33% (CI = 95%, range 0.0-3.14%). In Central-West Brazil (city of Brasilia), the MCPyV prevalence was 0.6% (CI = 95%, 0.0-1.96%). All MCPyV positive samples showed a high cycle threshold (median Ct = 35.5), most probably related to the low viral load. More studies are necessary to unveil the impact of this oncogenic virus on transfusion medicine and if such exists, especially in regards of its infectivity and transmission potential.


Assuntos
Poliomavírus das Células de Merkel , Infecções por Polyomavirus , Neoplasias Cutâneas , Humanos , Poliomavírus das Células de Merkel/genética , Infecções por Polyomavirus/epidemiologia , Brasil/epidemiologia , Prevalência , Doadores de Sangue , DNA Viral/genética
4.
J Med Microbiol ; 68(4): 622-626, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30843782

RESUMO

Parvovirus B19 (B19V) transmission may occur through blood transfusion as a result of asymptomatic viral persistence in blood donors. Our study evaluated the prevalence and viral load of B19V in blood donors from Brasilia, Federal District, Central-West Brazil. B19V DNA detection and quantification were performed in 477 blood donors. The positive samples were also tested for anti-B19V IgG and haemoderivative recipients were investigated for adverse effects following transfusion. B19V DNA prevalence was 0.21  % (n=1/477). The positive B19V DNA sample was also anti-B19 IgG-positive (probably persistent infection). The viral load was low and no adverse effects following blood transfusion were registered in the recipients. This study demonstrated that the B19V DNA prevalence in blood donors from Central-West Brazil is low. Nevertheless, the mere presence of B19V DNA in blood donors strengthens the need for viral molecular screening, especially in haemoderivatives that that will go to susceptible recipients.


Assuntos
Doadores de Sangue , DNA Viral/sangue , Infecções por Parvoviridae/sangue , Infecções por Parvoviridae/epidemiologia , Carga Viral , Adulto , Anticorpos Antivirais/sangue , Infecções Assintomáticas/epidemiologia , Transfusão de Sangue , Brasil/epidemiologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Infecções por Parvoviridae/transmissão , Parvovirus B19 Humano , Reação em Cadeia da Polimerase , Prevalência , Testes Sorológicos , Adulto Jovem
5.
J. Bras. Patol. Med. Lab. (Online) ; 54(4): 241-244, July-Aug. 2018. tab
Artigo em Inglês | LILACS | ID: biblio-1040210

RESUMO

ABSTRACT Parvovirus B19 (B19V) can be transmitted by the respiratory route, vertically - from the mother to the fetus - and via blood transfusion or organ transplantation. Infection by transfusion of blood or blood products occurs due to the resistance of B19V to viral inactivation methods. Our study evaluated the presence of B19V deoxyribonucleic acid (DNA) and the prevalence of anti-B19V class G immunoglobulin (IgG) in women of childbearing age blood donors of the Federal District, Brazil. Our results demonstrated the absence of B19V DNA in these blood donors. However, the seroprevalence for anti-B19V IgG was observed in 60.7% of this population. This study provides important data of B19V circulation in the Center-West of Brazil.


RESUMO O parvovírus B19 (B19V) pode ser transmitido por via respiratória, verticalmente - da mãe para o feto - e via transfusão de sangue e transplante de órgãos. A infecção por transfusão de sangue ou hemoderivados ocorre devido à resistência do B19V aos métodos de inativação viral. Nosso estudo avaliou a presença do ácido desoxirribonucleico (DNA) B19V e a prevalência de imunoglobulina da classe G (IgG) anti-B19V em mulheres em idade fértil, doadoras de sangue do Distrito Federal, Brasil. Nossos resultados demonstraram a ausência de DNA de B19V nesses doadores. No entanto, foi observada a soroprevalência de IgG anti-B19V em 60,7% dessa população. Este estudo fornece dados importantes da circulação do B19V no Centro-Oeste do Brasil.

6.
J. Bras. Patol. Med. Lab. (Online) ; 53(6): 400-402, Nov.-Dec. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-1040204

RESUMO

ABSTRACT Systemic lupus erythematosus (SLE) is considered an autoimmune disease characterized by the action of autoantibodies, which cause chronic inflammation in various tissues of the body. Considering the vascular endothelial growth factor (VEGF) participation in the development of inflammation, this study aimed to evaluate the frequency of the polymorphism at the -2549 position (Ins/Del 18pb, rs35569394) in patients with SLE and in healthy individuals. No statistical differences were found when comparing the allele and genotype frequencies between patients and controls, suggesting that there is no association between the studied polymorphism and the development of SLE.


RESUMO O lúpus eritematoso sistêmico (LES) é considerado uma doença autoimune devido à atuação de autoanticorpos, que ocasionam inflamações crônicas em diversos tecidos corporais. Considerando o envolvimento do fator de crescimento vascular endotelial (VEGF) no desenvolvimento da inflamação, este trabalho objetivou avaliar a frequência do polimorfismo na posição -2549 (Ins/Del 18pb, rs35569394) em pacientes com LES, comparando-os com indivíduos saudáveis. Não foram encontradas diferenças estatísticas ao comparar as frequências alélicas e genotípicas entre pacientes e controles, sugerindo que não há associação entre o desenvolvimento de LES e o polimorfismo estudado.

7.
Arch Virol ; 162(10): 3131-3136, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28608127

RESUMO

Approximately 5% of human T-cell leukemia virus type 1 (HTLV-1)-infected individuals will develop one of the HTLV-1-related diseases, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) or adult T-cell leukemia. However, the mechanisms responsible for the appearance of symptoms have not been fully clarified. It is believed that viral factors, host genetic and epigenetic mechanisms are implicated in this process. Studies have shown the involvement of histone methyltransferases in retrovirus infection, but no study observed their expression in HTLV-1-infected patients. Among them, euchromatic histone-lysine N-methyltransferase (EHMT)-1 and EHMT-2 were related to retroviral latency in HIV-1 infection. We investigated whether histone methyltransferases EHMT1 and EHMT2 exert any influence on HAM/TSP development by assessing their expression levels in CD4+ T-cells from HTLV-1-infected patients. CD4+ T-cells were immunomagnetically isolated from peripheral blood mononuclear cells of HTLV-1-infected or non-infected individuals and the expression levels of EHMT1 and EHMT2 were determined by RT-qPCR. We observed that EHMT2 was negatively regulated in HTLV-1 asymptomatic carriers compared to non-infected individuals. No difference was observed for EHMT1. These results suggest that EHMT2 downregulation in CD4+ T-cells may be linked to a protection mechanism against the development of HAM/TSP.


Assuntos
Antígenos de Histocompatibilidade/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Vírus Linfotrópico T Tipo 1 Humano , Paraparesia Espástica Tropical/genética , Paraparesia Espástica Tropical/virologia , Adulto , Linfócitos T CD4-Positivos , Feminino , Regulação Enzimológica da Expressão Gênica , Predisposição Genética para Doença , Antígenos de Histocompatibilidade/genética , Histona-Lisina N-Metiltransferase/genética , Humanos , Masculino , Pessoa de Meia-Idade
8.
J BUON ; 22(6): 1494-1499, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29332343

RESUMO

PURPOSE: To perform a systematic review to explore the clinical relevance of hTERT polymorphisms for breast cancer (BC). METHODS: Twenty-nine polymorphic regions were evaluated after comprehensive searching of 1236 articles, and selection of 9 publications (total of 12986 cases and 16758 controls). RESULTS: About the influence of hTERT variants in BC risk, 3 studies showed that the variant rs2736098 was associated with increasing risk. The variants rs10069690 and rs2853676 were also described as risk factors for BC. Only one variant rs2736100 presented as risk factor for BC. MNS16A genotype influenced the risk of BC in an Iranian, but not in the Greek and American populations. The associations of 5 hTERT variants with expression of hormone receptors were also evaluated in some studies. One study showed that the variant rs10069690 was associated to the estrogen receptor (ER)-negative and triple negative subtype, but other authors did not find the same results. In addition, the association of rs273618 with ER-/progesterone receptor (PR)+ cases, and rs10069690, rs2735940, rs4246742 and rs2736100 with both negative receptors were described. After data reanalyses, we found that the variant rs2735940 and rs2736100 were associated with ER-/PR- cases among patients with BC. Also, the variant rs2736100 was associated with ER+/PR+ cases and the variant rs2736118 was associated to ER+/PR+ and ER-/PR+ cases. CONCLUSIONS: The associations between hTERT variants and BC risk and outcomes could be useful since a polymorphism can be identified before the diagnosis, but the heterogeneity of data and analyses found in different studies lead to many controversies.


Assuntos
Neoplasias da Mama/genética , Polimorfismo de Nucleotídeo Único/genética , Telomerase/genética , Neoplasias da Mama/patologia , Feminino , Predisposição Genética para Doença , Humanos
9.
Stem Cell Res ; 19: 21-30, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28038351

RESUMO

Somatic cell reprogramming by transcription factors and other modifiers such as microRNAs has opened broad avenues for the study of developmental processes, cell fate determination, and interplay of molecular mechanisms in signaling pathways. However, many of the mechanisms that drive nuclear reprogramming itself remain yet to be elucidated. Here, we analyzed the role of miR-29 during reprogramming in more detail. Therefore, we evaluated miR-29 expression during reprogramming of fibroblasts transduced with lentiviral OKS and OKSM vectors and we show that addition of c-MYC to the reprogramming factor cocktail decreases miR-29 expression levels. Moreover, we found that transfection of pre-miR-29a strongly decreased OKS-induced formation of GFP+-colonies in MEF-cells from Oct4-eGFP reporter mouse, whereas anti-miR-29a showed the opposite effect. Furthermore, we studied components of two pathways which are important for reprogramming and which involve miR-29 targets: active DNA-demethylation and Wnt-signaling. We show that inhibition of Tet1, Tet2 and Tet3 as well as activation of Wnt-signaling leads to decreased reprogramming efficiency. Moreover, transfection of pre-miR-29 resulted in elevated expression of ß-Catenin transcriptional target sFRP2 and increased TCF/LEF-promoter activity. Finally, we report that Gsk3-ß is a direct target of miR-29 in MEF-cells. Together, our findings contribute to the understanding of the molecular mechanisms by which miR-29 influences reprogramming.


Assuntos
Reprogramação Celular , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Via de Sinalização Wnt/fisiologia , Regiões 3' não Traduzidas , Animais , Antagomirs/metabolismo , Sequência de Bases , Linhagem Celular , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Fibroblastos/citologia , Fibroblastos/metabolismo , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Células HEK293 , Humanos , Lentivirus/genética , Camundongos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Alinhamento de Sequência , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
J Gen Virol ; 97(10): 2742-2752, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27449667

RESUMO

Most human T-lymphotropic virus type 1 (HTLV-1)-infected patients remain asymptomatic throughout life. The factors associated with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) development have not been fully elucidated; immunological and genetic factors may be involved. The association of 14 bp INS/DEL HLA-G polymorphism with HTLV-1 infection susceptibility has been reported previously. Here, other polymorphic sites at the HLA-G 3'-UTR (14-bp D/I, +3003C/T, +3010C/G, +3027A/C, +3035C/T, +3142C/G, +3187A/G and +3196C/G) were evaluated in 37 HTLV-1-infected individuals exhibiting HAM/TSP, 45 HTLV-1 asymptomatic carriers (HAC) and 153 uninfected individuals, followed up at University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil. It was observed that: (i) 14bpDI genotype is a risk factor for HTLV-1 infection, while the 14bpDD and +3142CC genotypes were associated with protection against infection; (ii) the +3142C allele and the +3003CT and +3142CC genotypes were associated with susceptibility, while 14bpII and +3003TT genotypes were associated with protection against HAM/TSP development; and (iii) the 14bpII, +3010CC, +3142GG and +3187AA genotypes were associated with lower HTLV-1 proviral load compared to respective counterpart genotypes. Findings that HLA-G has a well-recognized immunomodulatory role and that the genetic variability at HLA-G 3'-UTR may post-transcriptionally modify HLA-G production indicate a differential genetic susceptibility to: (i) the development of HTLV-1 infection, (ii) the magnitude of HTLV-1 proviral load and (iii) HAM/TSP development.


Assuntos
Regiões 3' não Traduzidas , Antígenos HLA-G/genética , Infecções por HTLV-I/genética , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Paraparesia Espástica Tropical/genética , Polimorfismo Genético , Provírus/fisiologia , Doenças da Medula Espinal/genética , Adolescente , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Antígenos HLA-G/imunologia , Infecções por HTLV-I/imunologia , Infecções por HTLV-I/virologia , Vírus Linfotrópico T Tipo 1 Humano/genética , Humanos , Masculino , Pessoa de Meia-Idade , Paraparesia Espástica Tropical/imunologia , Paraparesia Espástica Tropical/virologia , Provírus/genética , Doenças da Medula Espinal/imunologia , Doenças da Medula Espinal/virologia , Adulto Jovem
11.
Cytotherapy ; 18(7): 846-59, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27260206

RESUMO

Multipotent mesenchymal stromal cells (MSC) are imbued with an immunosuppressive phenotype that extends to several immune system cells. In this study, we evaluated how distinct Toll-like receptor (TLR) agonists impact immunosuppressive properties of bone marrow (BM)-MSC and explored the potential mechanisms involved. We show that TLR4 stimulation by lipopolysaccharide (LPS) restricted the ability of MSC to suppress the proliferation of T lymphocytes, increasing the gene expression of interleukin (IL)-1ß and IL-6. In contrast, stimulation of TLR9 by DSP30 induced proliferation and the suppressive potential of BM-MSC, coinciding with reducing tumor necrosis factor (TNF)-α expression, increased expression of transforming growth factor (TGF)-ß1, increased percentages of BM-MSC double positive for the ectonucleotidases CD39+CD73+ and adenosine levels. Importantly, following simultaneous stimulation with LPS and DSP30, BM-MSC's ability to suppress T lymphocyte proliferation was comparable with that of non-stimulated BM-MSC levels. Moreover, stimulation of BM-MSC with LPS reduced significantly the gene expression levels, on co-cultured T lymphocyte, of IL-10 and interferon (IFN)γ, a cytokine with potential to enhance the immunosuppression mediated by MSC and ameliorate the clinical outcome of patients with graft-versus-host disease (GVHD). Altogether, our findings reiterate the harmful effects of LPS on MSC immunosuppression, besides indicating that DSP30 could provide a protective effect against LPS circulating in the blood of GVHD patients who receive BM-MSC infusions, ensuring a more predictable immunosuppressive effect. The novel effects and potential mechanisms following the stimulation of BM-MSC by DSP30 might impact their clinical use, by allowing the derivation of optimal "licensing" protocols for obtaining therapeutically efficient MSC.


Assuntos
Adenosina/farmacologia , Imunossupressores/farmacologia , Lipopolissacarídeos/farmacologia , Células-Tronco Mesenquimais/citologia , Antígenos CD/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Terapia de Imunossupressão , Ligantes , Ativação Linfocitária/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Oligonucleotídeos/farmacologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Receptores Toll-Like/metabolismo
12.
Cancer Sci ; 106(10): 1264-77, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26251039

RESUMO

Recent evidence has shown that deregulated expression of members of the microRNA-29 (miR-29) family may play a critical role in human cancer, including hematological malignancies. However, the roles of miR-29 in the molecular pathophysiology of T-cell acute lymphoblastic leukemia (T-ALL) has not been investigated. Here, we show that lower levels of miR-29a were significantly associated with higher blast counts in the bone marrow and with increased disease-free survival in T-ALL patients. Furthermore, miR-29a levels are extremely reduced in T-ALL cells compared to normal T cells. Microarray analysis following introduction of synthetic miR-29a mimics into Jurkat cells revealed the downregulation of several predicted targets (CDK6, PXDN, MCL1, PIK3R1, and CXXC6), including targets with roles in active and passive DNA demethylation (such as DNMT3a, DNMT3b, and members of the TET family and TDG). Restoring miR-29a levels in Jurkat and Molt-4 T-ALL cells led to the demethylation of many genes commonly methylated in T-ALL. Overall, our results suggest that reduced miR-29a levels may contribute to the altered epigenetic status of T-ALL, highlighting its relevance in the physiopathology of this disease.


Assuntos
Metilação de DNA/genética , Epigênese Genética/genética , Regulação Leucêmica da Expressão Gênica/genética , MicroRNAs/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Antígenos de Neoplasias/biossíntese , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Classe Ia de Fosfatidilinositol 3-Quinase , Quinase 6 Dependente de Ciclina/biossíntese , DNA (Citosina-5-)-Metiltransferases/genética , DNA Metiltransferase 3A , Proteínas de Ligação a DNA/biossíntese , Daunorrubicina/farmacologia , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Células Jurkat , Oxigenases de Função Mista , Proteína de Sequência 1 de Leucemia de Células Mieloides/biossíntese , Análise de Sequência com Séries de Oligonucleotídeos , Peroxidases , Fosfatidilinositol 3-Quinases/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Receptores de Interleucina-1/biossíntese , DNA Metiltransferase 3B
13.
Biomed Res Int ; 2014: 216806, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25025040

RESUMO

Mesenchymal stromal cells (MSCs) are multipotent cells, which can give rise to several cell types including osteoblasts, adipocytes, and chondroblasts. These cells can be found in a variety of adult and fetal tissues, such as bone marrow, adipose tissue, cord blood, and placenta. In recent years, the biological properties of MSCs have attracted the attention of researchers worldwide due to their potential application for treating a series of clinical situations. Among these properties, special attention should be given to the immunoregulatory potential of those cells. MSCs are able to act on all cells of the immune system, which includes the capacity to inhibit the proliferation and function of T-cells. This feature renders them natural candidates to treat several diseases in which cellular immune response is exacerbated. In this review, we outline the main mechanisms by which MSCs immunosuppress T-cell response, focusing on cell-cell contact, secretion of soluble factors, and regulatory T-cell generation. The influence of surface markers in the immunosuppression process and features of MSCs isolated from different sources are also discussed. Finally, the influences of toll-like receptors and cytokines on the inflammatory microenvironment are highlighted regarding the activation of MSCs to exert their immunoregulatory function.


Assuntos
Diferenciação Celular/genética , Terapia de Imunossupressão , Células-Tronco Mesenquimais , Linfócitos T/imunologia , Adipócitos/citologia , Adipócitos/imunologia , Condrócitos/citologia , Condrócitos/imunologia , Humanos , Imunidade Celular , Osteoblastos/citologia , Osteoblastos/imunologia , Linfócitos T/citologia
14.
Mem Inst Oswaldo Cruz ; 107(6): 824-7, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22990976

RESUMO

The retrovirus human T lymphotropic virus type 1 (HTLV-1) promotes spastic paraparesis, adult T cell leukaemia and other diseases. Recently, some human microRNAs (miRNAs) have been described as important factors in host-virus interactions. This study compared miRNA expression in control individuals, asymptomatic HTLV-1 carriers and HTLV-1 associated myelopathy (HAM)/tropical spastic paraparesis patients. The proviral load and Tax protein expression were measured in order to characterize the patients. hsa-miR-125b expression was significantly higher in patients than in controls (p = 0.0285) or in the HAM group (p = 0.0312). Therefore, our findings suggest that miR-125b expression can be used to elucidate the mechanisms of viral replication and pathogenic processes.


Assuntos
Produtos do Gene tax/metabolismo , MicroRNAs/metabolismo , Paraparesia Espástica Tropical/metabolismo , Adulto , Biomarcadores/metabolismo , Portador Sadio , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Vírus Linfotrópico T Tipo 1 Humano/crescimento & desenvolvimento , Humanos , Masculino , Pessoa de Meia-Idade , Paraparesia Espástica Tropical/virologia , Regulação para Cima , Carga Viral , Replicação Viral
15.
Mem. Inst. Oswaldo Cruz ; 107(6): 824-827, set. 2012. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-649502

RESUMO

The retrovirus human T lymphotropic virus type 1 (HTLV-1) promotes spastic paraparesis, adult T cell leukaemia and other diseases. Recently, some human microRNAs (miRNAs) have been described as important factors in host-virus interactions. This study compared miRNA expression in control individuals, asymptomatic HTLV-1 carriers and HTLV-1 associated myelopathy (HAM)/tropical spastic paraparesis patients. The proviral load and Tax protein expression were measured in order to characterize the patients. hsa-miR-125b expression was significantly higher in patients than in controls (p = 0.0285) or in the HAM group (p = 0.0312). Therefore, our findings suggest that miR-125b expression can be used to elucidate the mechanisms of viral replication and pathogenic processes.


Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Produtos do Gene tax/metabolismo , MicroRNAs/metabolismo , Paraparesia Espástica Tropical/metabolismo , Biomarcadores/metabolismo , Portador Sadio , Estudos de Casos e Controles , Citometria de Fluxo , Vírus Linfotrópico T Tipo 1 Humano/crescimento & desenvolvimento , Paraparesia Espástica Tropical/virologia , Regulação para Cima , Carga Viral , Replicação Viral
16.
J Cell Mol Med ; 16(6): 1232-44, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21777379

RESUMO

Mesenchymal stem cells (MSCs) are known to induce the conversion of activated T cells into regulatory T cells in vitro. The marker CD69 is a target of canonical nuclear factor kappa-B (NF-κB) signalling and is transiently expressed upon activation; however, stable CD69 expression defines cells with immunoregulatory properties. Given its enormous therapeutic potential, we explored the molecular mechanisms underlying the induction of regulatory cells by MSCs. Peripheral blood CD3(+) T cells were activated and cultured in the presence or absence of MSCs. CD4(+) cell mRNA expression was then characterized by microarray analysis. The drug BAY11-7082 (BAY) and a siRNA against v-rel reticuloendotheliosis viral oncogene homolog B (RELB) were used to explore the differential roles of canonical and non-canonical NF-κB signalling, respectively. Flow cytometry and real-time PCR were used for analyses. Genes with immunoregulatory functions, CD69 and non-canonical NF-κB subunits (RELB and NFKB2) were all expressed at higher levels in lymphocytes co-cultured with MSCs. The frequency of CD69(+) cells among lymphocytes cultured alone progressively decreased after activation. In contrast, the frequency of CD69(+) cells increased significantly following activation in lymphocytes co-cultured with MSCs. Inhibition of canonical NF-κB signalling by BAY immediately following activation blocked the induction of CD69; however, inhibition of canonical NF-κB signalling on the third day further induced the expression of CD69. Furthermore, late expression of CD69 was inhibited by RELB siRNA. These results indicate that the canonical NF-κB pathway controls the early expression of CD69 after activation; however, in an immunoregulatory context, late and sustained CD69 expression is promoted by the non-canonical pathway and is inhibited by canonical NF-κB signalling.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Lectinas Tipo C/metabolismo , Ativação Linfocitária/imunologia , Células-Tronco Mesenquimais/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Linfócitos T Reguladores/imunologia , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Proliferação de Células , Células Cultivadas , Perfilação da Expressão Gênica , Humanos , Lectinas Tipo C/genética , Análise em Microsséries , NF-kappa B/genética , Nitrilas , Transplante de Células-Tronco de Sangue Periférico/métodos , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real , Sulfonas , Linfócitos T Reguladores/metabolismo , Fator de Transcrição RelB/genética , Fator de Transcrição RelB/metabolismo
17.
Anticancer Res ; 31(6): 2173-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21737637

RESUMO

BACKGROUND: Human T-lymphotropic virus I (HTLV-1) is associated with the T-cell malignancy known as adult T-cell leukemia/ lymphoma (ATLL) and with a disorder called HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Currently, the treatment of these diseases is based on symptom relief. RNA interference (RNAi) technology has been described as an efficient mechanism for development of new therapeutic methods. Thus, the aim of this study was to evaluate the inhibition of HTLV-1 structural proteins using short hairpin RNAs (shRNAs) expressed by non-viral vectors. MATERIALS AND METHODS: Reporter plasmids that express enhanced green fluorescent protein-Gag (EGFP-Gag) and EGFP-Env fusion proteins and vectors that express shRNAs corresponding to the HTLV-1 gag and env genes were constructed. shRNA vectors and reporter plasmids were simultaneously transfected into HEK 293 cells. RESULTS: Fluorescence microscopy, flow cytometry and real-time PCR showed that shRNAs were effective in inhibiting the fusion proteins. CONCLUSION: These shRNAs are effective against the expression of structural genes and may provide an approach to the development of new therapeutic agents.


Assuntos
Regulação Viral da Expressão Gênica , Vírus Linfotrópico T Tipo 1 Humano/genética , RNA Interferente Pequeno/genética , Receptores ErbB/biossíntese , Receptores ErbB/genética , Citometria de Fluxo , Produtos do Gene env/biossíntese , Produtos do Gene env/genética , Produtos do Gene gag/biossíntese , Produtos do Gene gag/genética , Vetores Genéticos/genética , Células HEK293 , Humanos , Microscopia de Fluorescência , Reação em Cadeia da Polimerase/métodos , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Transfecção , Transformação Genética
18.
J Virol Methods ; 173(1): 92-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21277903

RESUMO

Since the discovery of RNAi technology, several functional genomic and disease therapy studies have been conducted using this technique in the field of oncology and virology. RNAi-based antiviral therapies are being studied for the treatment of retroviruses such as HIV-1. These studies include the silencing of regulatory, infectivity and structural genes. The HTLV-1 structural genes are responsible for the synthesis of proteins involved in the entry, assembly and release of particles during viral infection. To examine the possibility of silencing HTLV-1 genes gag and env by RNA interference technology, these genes were cloned into reporter plasmids. These vectors expressed the target mRNAs fused to EGFP reporter genes. Three small interference RNAs (siRNAs) corresponding to gag and three corresponding to env were designed to analyze the effect of silencing by RNAi technology. The plasmids and siRNAs were co-transfected into HEK 293 cells. The results demonstrated that the expression of the HTLV-1 gag and env genes decreased significantly in vitro. Thus, siRNAs can be used to inhibit HTLV-1 structural genes in transformed cells, which could provide a tool for clarifying the roles of HTLV-1 structural genes, as well as a therapy for this infection.


Assuntos
Produtos do Gene env/antagonistas & inibidores , Produtos do Gene gag/antagonistas & inibidores , Inativação Gênica , Vírus Linfotrópico T Tipo 1 Humano/genética , RNA Interferente Pequeno/genética , Fusão Gênica Artificial , Produtos do Gene env/genética , Produtos do Gene gag/genética , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos
19.
AIDS Res Hum Retroviruses ; 27(3): 283-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20977358

RESUMO

About 95% of HTLV-1 infected patients remain asymptomatic throughout life, and the risk factors associated with the development of related diseases, such as HAM/TSP and ATL, are not fully understood. The human leukocyte antigen-G molecule (HLA-G), a nonclassical HLA class I molecule encoded by MHC, is expressed in several pathological conditions, including viral infection, and is related to immunosuppressive effects that allow the virus-infected cells to escape the antiviral defense of the host. The 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene influences the stability of the transcripts and could be related to HTLV-1-infected cell protection and to the increase of proviral load. The present study analyzed by conventional PCR the 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene in 150 unrelated healthy subjects, 82 HTLV-1 infected patients with symptoms (33 ATL and 49 HAM), and 56 asymptomatic HTLV-1 infected patients (HAC). In addition, the proviral load was determined by quantitative real-time PCR in all infected groups and correlated with 14-bp insertion/deletion genotypes. The heterozygote genotype frequencies were significantly higher in HAM, in the symptomatic group, and in infected patients compared to control (p < 0.05). The proviral load was higher in the symptomatic group than the HAC group (p < 0.0005). The comparison of proviral load and genotypes showed that -14-bp/-14-bp genotype had a higher proviral load than +14-bp/-14-bp and +14-bp/+14-bp genotypes. Although HLA-G 14-bp polymorphism does not appear to be associated with HTLV-1 related disease development, it could be a genetic risk factor for susceptibility to infection.


Assuntos
Infecções por Deltaretrovirus/genética , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Mutação INDEL , Polimorfismo Genético , Adolescente , Adulto , Idoso , DNA Viral/genética , Suscetibilidade a Doenças , Feminino , Genótipo , Antígenos HLA-G , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fatores de Risco , Carga Viral/genética
20.
Anticancer Res ; 30(12): 5023-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21187485

RESUMO

BACKGROUND/AIMS: The expression of cancer/testis antigens (CTAs) on additional normal tissues or stem cells may restrict their use as cancer targets. The objective of the present study was to evaluate the mRNA levels of some CTAs in a variety of tissues. MATERIALS AND METHODS: mRNA of pericytes, fibroblasts and mesenchymal stem cells (MSCs) derived from adult and fetal tissues, human umbilical vein endothelial cells, MSC-derived adipocytes, selected normal tissues and control cancer cell lines (CLs) were extracted and quantitative polymerase chain reaction was performed for MAGED1, PRAME, CTAG1B, MAGEA3 and MAGEA4. RESULTS: MAGED1 was expressed in all normal tissues and cells evaluated. CTAG1B was expressed at levels comparable to control CLs on MSCs derived from arterial, fetal skin, adipose tissue and saphenous vein, heart, brain and skin tissues. MAGEA4 was detected only in fibroblasts and differentiated adipocytes from MSCs, at levels comparable to the control CLs. CONCLUSION: The potential use of CTAs in immunotherapy should take into account the potential off-target effects on MSCs.


Assuntos
Antígenos de Neoplasias/biossíntese , Células-Tronco Mesenquimais/imunologia , Fibroblastos/imunologia , Humanos , Imunofenotipagem , Antígenos Específicos de Melanoma , Proteínas de Membrana/biossíntese , Proteínas de Neoplasias/biossíntese , Pericitos/imunologia
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