RESUMO
The combination of signals from the T-cell receptor (TCR) and co-stimulatory molecules triggers transcriptional programs that lead to proliferation, cytokine secretion, and effector functions. We compared the impact of engaging the TCR with CD28 and/or CD43 at different time points relative to TCR engagement on T-cell function. TCR and CD43 simultaneous engagement resulted in higher CD69 and PD-1 expression levels than in TCR and CD28-stimulated cells, with a cytokine signature of mostly effector, inflammatory, and regulatory cytokines, while TCR and CD28-activated cells secreted all categories of cytokines, including stimulatory cytokines. Furthermore, the timing of CD43 engagement relative to TCR ligation, and to a lesser degree that of CD28, resulted in distinct patterns of expression of cytokines, chemokines, and growth factors. Complete cell activation was observed when CD28 or CD43 were engaged simultaneously with or before the TCR, but ligating the TCR before CD43 or CD28 failed to complete a cell activation program regarding cytokine secretion. As the order in which CD43 or CD28 and the TCR were engaged resulted in different combinations of cytokines that shape distinct T-cell immune programs, we analyzed their upstream sequences to assess whether the combinations of cytokines were associated with different sets of regulatory elements. We found that the order in which the TCR and CD28 or CD43 are engaged predicts the recruitment of specific sets of chromatin remodelers and TFSS, which ultimately regulate T-cell polarization and plasticity. Our data underscore that the combination of co-stimulatory molecules and the time when they are engaged relative to the TCR can change the cell differentiation program.
Assuntos
Antígenos CD28 , Receptores de Antígenos de Linfócitos T , Antígenos CD28/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T , Ativação Linfocitária , Diferenciação Celular , Citocinas/metabolismoRESUMO
Inorganic arsenic is a well-known carcinogen associated with several types of cancer, but the mechanisms involved in arsenic-induced carcinogenesis are not fully understood. Recent evidence points to epigenetic dysregulation as an important mechanism in this process; however, the effects of epigenetic alterations in gene expression have not been explored in depth. Using microarray data and applying a multivariate clustering analysis in a Gaussian mixture model, we describe the alterations in DNA methylation around the promoter region and the impact on gene expression in HaCaT cells during the transformation process caused by chronic exposure to arsenic. Using this clustering approach, the genes were grouped according to their methylation and expression status in the epigenetic landscape, and the changes that occurred during the cellular transformation were identified adequately. Thus, we present a valuable method for identifying epigenomic dysregulation.
Assuntos
Arsênio/toxicidade , Transformação Celular Neoplásica/patologia , Metilação de DNA/efeitos dos fármacos , Perfilação da Expressão Gênica/métodos , Neoplasias Cutâneas/patologia , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Transplante de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/genéticaRESUMO
In prostate cancer (PCa), neuroendocrine cells (NE) have been associated with the progression of the disease due to the secretion of neuropeptides that are capable of diffusing and influence surrounding cells. The GABAergic system is enriched in NE-like cells, and contributes to PCa progression. Additionally, γ-aminobutyric acid (GABA) stimulates the secretion of gastrin-releasing peptide (GRP) in peripheral organs. For the first time, in this study we show the role of GABA and GABAB receptor 1 (GABBR1) expression in GRP secretion in NE-like prostate cancer cells. We demonstrated an increase in GRP levels in NE-like cell medium treated with GABAB receptor agonist. Moreover, the blocking of this receptor inhibited GABA-induced GRP secretion. The invasive potential of PC3 cells was enhanced by either GRP or conditioned medium of NE-like cells treated with GABA. Additionally, we confirmed a positive correlation between GABA and GRP levels in the serum of PCa patients with NE markers. Finally, using public available data sets, we found a negative correlation between GABBR1 and androgen receptor (AR) expression, as well as a strong positive correlation between GABBR1 and enolase 2. These results suggest that GABA via GABBR1 induces GRP secretion in NE like cells involved in PCa progression.
Assuntos
Adenocarcinoma/patologia , GABAérgicos/farmacologia , Peptídeo Liberador de Gastrina/metabolismo , Células Neuroendócrinas/patologia , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Ácido gama-Aminobutírico/farmacologia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Idoso , Estudos de Coortes , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Células Neuroendócrinas/efeitos dos fármacos , Células Neuroendócrinas/metabolismo , Hiperplasia Prostática/tratamento farmacológico , Hiperplasia Prostática/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , RNA Interferente Pequeno/genética , Receptores Androgênicos/química , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Células Tumorais CultivadasRESUMO
BACKGROUND: Obesity is a well-recognized risk factor for insulin resistance and type 2 diabetes (T2D), although the precise mechanisms underlying the relationship remain unknown. In this study we identified alterations of DNA methylation influencing T2D pathogenesis, in subcutaneous and visceral adipose tissues, liver, and blood from individuals with obesity. METHODS: The study included individuals with obesity, with and without T2D. From these patients, we obtained samples of liver tissue (n = 16), visceral and subcutaneous adipose tissues (n = 30), and peripheral blood (n = 38). We analyzed DNA methylation using Illumina Infinium Human Methylation arrays, and gene expression profiles using HumanHT-12 Expression BeadChip Arrays. RESULTS: Analysis of DNA methylation profiles revealed several loci with differential methylation between individuals with and without T2D, in all tissues. Aberrant DNA methylation was mainly found in the liver and visceral adipose tissue. Gene ontology analysis of genes with altered DNA methylation revealed enriched terms related to glucose metabolism, lipid metabolism, cell cycle regulation, and response to wounding. An inverse correlation between altered methylation and gene expression in the four tissues was found in a subset of genes, which were related to insulin resistance, adipogenesis, fat storage, and inflammation. CONCLUSIONS: Our present findings provide additional evidence that aberrant DNA methylation may be a relevant mechanism involved in T2D pathogenesis among individuals with obesity.
Assuntos
Metilação de DNA , Diabetes Mellitus Tipo 2/genética , Gordura Intra-Abdominal/metabolismo , Fígado/metabolismo , Obesidade/genética , Adipogenia , Adulto , Índice de Massa Corporal , Ilhas de CpG , Epigênese Genética , Ontologia Genética , Estudo de Associação Genômica Ampla , Humanos , Resistência à Insulina , Metabolismo dos Lipídeos , Pessoa de Meia-Idade , TranscriptomaRESUMO
Since the emergence of the pandemic H1N1pdm09 virus in Mexico and California, biannual increases in the number of cases have been detected in Mexico. As observed in previous seasons, pandemic A/H1N1 09 virus was detected in severe cases during the 2011-2012 winter season and finally, during the 2013-2014 winter season it became the most prevalent influenza virus. Molecular and phylogenetic analyses of the whole viral genome are necessary to determine the antigenic and pathogenic characteristics of influenza viruses that cause severe outcomes of the disease. In this paper, we analyzed the evolution, antigenic and genetic drift of Mexican isolates from 2009, at the beginning of the pandemic, to 2014. We found a clear variation of the virus in Mexico from the 2011-2014 season due to different markers and in accordance with previous reports. In this study, we identified 13 novel substitutions with important biological effects, including virulence, T cell epitope presented by MHC and host specificity shift and some others substitutions might have more than one biological function. The systematic monitoring of mutations on whole genome of influenza A pH1N1 (2009) virus circulating at INER in Mexico City might provide valuable information to predict the emergence of new pathogenic influenza virus.
Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/epidemiologia , Influenza Humana/virologia , Estações do Ano , Substituição de Aminoácidos/genética , Antígenos Virais/imunologia , Demografia , Feminino , Genoma Viral , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Funções Verossimilhança , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Filogenia , Prevalência , Análise de Sequência de DNARESUMO
BACKGROUND: Human central memory CD4 T cells are characterized by their capacity of proliferation and differentiation into effector memory CD4 T cells. Homeostasis of central memory CD4 T cells is considered a key factor sustaining the asymptomatic stage of Human Immunodeficiency Virus type 1 (HIV-1) infection, while progression to acquired immunodeficiency syndrome is imputed to central memory CD4 T cells homeostatic failure. We investigated if central memory CD4 T cells from patients with HIV-1 infection have a gene expression profile impeding proliferation and survival, despite their activated state. METHODS: Using gene expression microarrays, we analyzed mRNA expression patterns in naive, central memory, and effector memory CD4 T cells from healthy controls, and naive and central memory CD4 T cells from patients with HIV-1 infection. Differentially expressed genes, defined by Log2 Fold Change (FC) ≥ |0.5| and Log (odds) > 0, were used in pathway enrichment analyses. RESULTS: Central memory CD4 T cells from patients and controls showed comparable expression of differentiation-related genes, ruling out an effector-like differentiation of central memory CD4 T cells in HIV infection. However, 210 genes were differentially expressed in central memory CD4 T cells from patients compared with those from controls. Expression of 75 of these genes was validated by semi quantitative RT-PCR, and independently reproduced enrichment results from this gene expression signature. The results of functional enrichment analysis indicated movement to cell cycle phases G1 and S (increased CCNE1, MKI67, IL12RB2, ADAM9, decreased FGF9, etc.), but also arrest in G2/M (increased CHK1, RBBP8, KIF11, etc.). Unexpectedly, the results also suggested decreased apoptosis (increased CSTA, NFKBIA, decreased RNASEL, etc.). Results also suggested increased IL-1ß, IFN-γ, TNF, and RANTES (CCR5) activity upstream of the central memory CD4 T cells signature, consistent with the demonstrated milieu in HIV infection. CONCLUSIONS: Our findings support a model where progressive loss of central memory CD4 T cells in chronic HIV-1 infection is driven by increased cell cycle entry followed by mitotic arrest, leading to a non-apoptotic death pathway without actual proliferation, possibly contributing to increased turnover.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Infecções por HIV/genética , Infecções por HIV/imunologia , Memória Imunológica/genética , Transcriptoma , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/virologia , Ciclo Celular/genética , Morte Celular/genética , Morte Celular/imunologia , Diferenciação Celular/genética , Senescência Celular/genética , Análise por Conglomerados , Perfilação da Expressão Gênica , Infecções por HIV/virologia , HIV-1 , Humanos , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/virologiaRESUMO
An important NK-cell inhibition with reduced TNF-α, IFN-γ and TLR2 expression had previously been identified in patients with diffuse cutaneous leishmaniasis (DCL) infected with Leishmania mexicana. In an attempt to pinpoint alterations in the signaling pathways responsible for the NK-cell dysfunction in patients with DCL, this study aimed at identifying differences in the NK-cell response towards Leishmania mexicana lipophosphoglycan (LPG) between patients with localized and diffuse cutaneous leishmaniasis through gene expression profiling. Our results indicate that important genes involved in the innate immune response to Leishmania are down-regulated in NK cells from DCL patients, particularly TLR and JAK/STAT signaling pathways. This down-regulation showed to be independent of LPG stimulation. The study sheds new light for understanding the mechanisms that undermine the correct effector functions of NK cells in patients with diffuse cutaneous leishmaniasis contributing to a better understanding of the pathobiology of leishmaniasis.