55 resultados para HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 INFECTION


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We report for the first time the genetic and biological characterization of 10 HIV-1 primary isolates representing CRF28_BF and CRF29_BF together with additional unique BF recombinant forms (URFs) obtained by PBMC cocultivation. Recombination is an important factor promoting the increase in the genetic diversity of HIV-1. Notably, more than 20% of HIV-1 sequences worldwide were recombinants. Several recombinant viruses were reported in Brazil, and six circulating recombinant forms (CRFs) have been identified (CRF28_BF, CRF29_BF, CRF31_BC, CRF39_BF, CRF40_BF, and CRF46_BF). CRF28_BF and CRF29_BF were found to infect almost 30% of the patients in Sao Paulo State. The near full-length genomes of these 10 primary isolates were amplified by nested PCR in three overlapping segments, purified, and sequenced. Three samples were related to CRF28_BF, three to CRF29_BF, and four were unique recombinant forms (URFs), as determined by their breakpoint profile determined with the jpHMM program. Additionally, the coreceptor usage of these isolates was investigated in vitro using GHOST assays, which revealed three dual-tropic (X4/R5) viruses, four lymphotropic (X4) viruses, and three macrophage-tropic (R5) viruses with different V3-loop motifs, which challenges the notion that GWGR-carrying viruses are macrophage-tropic only. In sum, we report a much-anticipated well-characterized panel of viruses representing CRF28_BF, CRF29_BF, and URFs from Sao Paulo State, Brazil.

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Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by T cell-mediated destruction of pancreatic beta cells, resulting in insulin deficiency and hyperglycaemia. Recent studies have described that apoptosis impairment during central and peripheral tolerance is involved in T1D pathogenesis. In this study, the apoptosis-related gene expression in T1D patients was evaluated before and after treatment with high-dose immunosuppression followed by autologous haematopoietic stem cell transplantation (HDI-AHSCT). We also correlated gene expression results with clinical response to HDI-AHSCT. We observed a decreased expression of bad, bax and fasL pro-apoptotic genes and an increased expression of a1, bcl-xL and cIAP-2 anti-apoptotic genes in patients' peripheral blood mononuclear cells (PBMCs) compared to controls. After HDI-AHSCT, we found an up-regulation of fas and fasL and a down-regulation of anti-apoptotic bcl-xL genes expression in post-HDI-AHSCT periods compared to pre-transplantation. Additionally, the levels of bad, bax, bok, fasL, bcl-xL and cIAP-1 genes expression were found similar to controls 2 years after HDI-AHSCT. Furthermore, over-expression of pro-apoptotic noxa at 540 days post-HDI-AHSCT correlated positively with insulin-free patients and conversely with glutamic acid decarboxylase autoantibodies (GAD65) autoantibody levels. Taken together, the results suggest that apoptosis-related genes deregulation in patients' PBMCs might be involved in breakdown of immune tolerance and consequently contribute to T1D pathogenesis. Furthermore, HDI-AHSCT modulated the expression of some apoptotic genes towards the levels similar to controls. Possibly, the expression of these apoptotic molecules could be applied as biomarkers of clinical remission of T1D patients treated with HDI-AHSCT therapy.

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The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302(9.93%), by serology in 46/302(15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66(18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66(7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p < 0.0001), but not with T. gondii (p > 0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with Fly, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections. (C) 2012 Elsevier B.V. All rights reserved.

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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.

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Intranasal inoculation of equid herpesvirus type-1 (EHV-1) Brazilian strains A4/72 and A9/92 induced an acute and lethal infection in four different inbred mouse strains. Clinical and neurological signs appeared between the 2nd and 3rd day post inoculation (dpi) and included weight loss, ruffled fur, a hunched posture, crouching in corners, nasal and ocular discharges, dyspnoea, dehydration and increased salivation. These signs were followed by increased reactivity to external stimulation, seizures, recumbency and death. The virus was recovered consistently from the brain and viscera of all mice with neurological signs. Histopathological changes consisted of leptomeningitis, focal haemorrhage, ventriculitis, neuronal degeneration and necrosis, neuronophagia, non-suppurative inflammation, multifocal gliosis and perivascular infiltration of polymorphonuclear and mononuclear cells. Immunohistochemical examination demonstrated that EHV-1 strains A4/72 and A9/92 replicated in neurons of the olfactory bulb, the cortex and the hippocampus. In contrast, mice inoculated with the EHV-1 Brazilian strain A3/97 showed neither weight loss nor apparent clinical or neurological signs; however, the virus was recovered consistently from their lungs at 3 dpi. These three EHV-1 strains showed distinct degrees of virulence and tissue tropism in mice. EHV-1 strains A4/72 and A9/92 exhibited a high degree of central nervous system tropism with neuroinvasion and neurovirulence. EHV-1 strain A3/97 was not neurovirulent despite being detected in the brains of infected BALB/c nude mice. These findings indicate that several inbred mouse strains are susceptible to neuropathogenic EHV-1 strains and should be useful models for studying the pathogenesis and mechanisms contributing to EHV-induced myeloencephalopathy in horses. (C) 2011 Elsevier Ltd. All rights reserved.

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The objective of this study was to determine the frequencies of autoantibodies to heterogeneous islet-cell cytoplasmic antigens (ICA), glutamic acid decarboxylase(65) (GAD(65)A), insulinoma-associated antigen-2 (IA-2A) and insulin (IAA)-and human leukocyte antigen (HLA) class II markers (HLA-DR and -DQ) in first degree relatives of heterogeneous Brazilian patients with type I diabetes(T1DM). A major focus of this study was to determine the influence of age, gender, proband characteristics and ancestry on the prevalence of autoantibodies and HLA-DR and -DQ alleles on disease progression and genetic predisposition to T1DM among the first-degree relatives. IAA, ICA, GAD(65)A, IA-2A and HLA- class II alleles were determined in 546 first-degree-relatives, 244 siblings, 55 offspring and 233 parents of 178 Brazilian patients with T1DM. Overall, 8.9% of the relatives were positive for one or more autoantibodies. IAA was the only antibody detected in parents. GAD(65) was the most prevalent antibody in offspring and siblings as compared to parents and it was the sole antibody detected in offspring. Five siblings were positive for the IA-2 antibody. A significant number (62.1%) of siblings had 1 or 2 high risk HLA haplotypes. During a 4-year follow-up study, 5 siblings (expressing HLA-DR3 or -DR4 alleles) and 1 offspring positive for GAD(65)A progressed to diabetes. The data indicated that the GAD(65) and IA-2 antibodies were the strongest predictors of T1DM in our study population. The high risk HLA haplotypes alone were not predictive of progression to overt diabetes.

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Introduction: Primary HIV infection is usually caused by R5 viruses, and there is an association between the emergence of CCXR4-utilizing strains and faster disease progression. We characterized HIV-1 from a cohort of recently infected individuals in Brazil, predicted the virus's co-receptor use based on the env genotype and attempted to correlate virus profiles with disease progression. Methods: A total of 72 recently infected HIV patients were recruited based on the Serologic Testing Algorithm for Recent HIV Seroconversion and were followed every three to four months for up to 78 weeks. The HIV-1 V3 region was characterized by sequencing nine to twelve weeks after enrollment. Disease progression was characterized by CD4+ T-cell count decline to levels consistently below 350 cells/mu L. Results: Twelve out of 72 individuals (17%) were predicted to harbor CXCR4-utilizing strains; a baseline CD4,350 was more frequent among these individuals (p = 0.03). Fifty-seven individuals that were predicted to have CCR5-utilizing viruses and 10 individuals having CXCR4-utilizing strains presented with baseline CD4.350; after 78 weeks, 33 individuals with CCR5 strains and one individual with CXCR4 strains had CD4.350 (p = 0.001). There was no association between CD4 decline and demographic characteristics or HIV-1 subtype. Conclusions: Our findings confirm the presence of strains with higher in vitro pathogenicity during early HIV infection, suggesting that even among recently infected individuals, rapid progression may be a consequence of the early emergence of CXCR4-utilizing strains. Characterizing the HIV-1 V3 region by sequencing may be useful in predicting disease progression and guiding treatment initiation decisions.

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Adenosine deaminases acting on RNA (ADARs) catalyze the hydrolytic deamination of adenosine to inosine in double-stranded RNA (dsRNA) and thereby potentially alter the information content and structure of cellular RNAs. Notably, although the overwhelming majority of such editing events occur in transcripts derived from Alu repeat elements, the biological function of non-coding RNA editing remains uncertain. Here, we show that mutations in ADAR1 (also known as ADAR) cause the autoimmune disorder Aicardi-Goutieres syndrome (AGS). As in Adar1-null mice, the human disease state is associated with upregulation of interferon-stimulated genes, indicating a possible role for ADAR1 as a suppressor of type I interferon signaling. Considering recent insights derived from the study of other AGS-related proteins, we speculate that ADAR1 may limit the cytoplasmic accumulation of the dsRNA generated from genomic repetitive elements.

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Objective: To evaluate the effect of vitamin D-3 on cytokine levels, regulatory T cells, and residual beta-cell function decline when cholecalciferol (vitamin D-3 administered therapeutically) is given as adjunctive therapy with insulin in new-onset type 1 diabetes mellitus (T1DM). Design and Setting: An 18-month (March 10, 2006, to October 28, 2010) randomized, double-blind, placebo-controlled trial was conducted at the Diabetes Center of Sao Paulo Federal University, Sao Paulo, Brazil. Participants: Thirty-eight patients with new-onset T1DM with fasting serum C-peptide levels greater than or equal to 0.6 ng/mL were randomly assigned to receive daily oral therapy of cholecalciferol, 2000 IU, or placebo. Main Outcome Measure: Levels of proinflammatory and anti-inflammatory cytokines, chemokines, regulatory T cells, hemoglobin A(1c), and C-peptide; body mass index; and insulin daily dose. Results: Mean (SD) chemokine ligand 2 (monocyte chemoattractant protein 1) levels were significantly higher (184.6 [101.1] vs 121.4 [55.8] pg/mL) at 12 months, as well as the increase in regulatory T-cell percentage (4.55%[1.5%] vs 3.34%[1.8%]) with cholecalciferol vs placebo. The cumulative incidence of progression to undetectable (<= 0.1 ng/mL) fasting C-peptide reached 18.7% in the cholecalciferol group and 62.5% in the placebo group; stimulated C-peptide reached 6.2% in the cholecalciferol group and 37.5% in the placebo group at 18 months. Body mass index, hemoglobin A(1c) level, and insulin requirements were similar between the 2 groups. Conclusions: Cholecalciferol used as adjunctive therapy with insulin is safe and associated with a protective immunologic effect and slow decline of residual beta-cell function in patients with new-onset T1DM. Cholecalciferol may be an interesting adjuvant in T1DM prevention trials.

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Objective: To evaluate cases of mother-to-child transmission of HIV-1 at multiple sites in Latin America and the Caribbean in terms of missed opportunities for prevention. Methods: Pregnant women infected with HIV-1 were eligible for inclusion if they were enrolled in either the NISDI Perinatal or LILAC protocols by October 20, 2009, and had delivered a live infant with known HIV-1 infection status after March 1, 2006. Results: Of 711 eligible mothers, 10 delivered infants infected with HIV-1. The transmission rate was 1.4% (95% CI, 0.7-2.6). Timing of transmission was in utero or intrapartum (n = 5), intrapartum (n = 2), intrapartum or early postnatal (n = 1), and unknown (n = 2). Possible missed opportunities for prevention included poor control of maternal viral load during pregnancy; late initiation of antiretrovirals during pregnancy; lack of cesarean delivery before labor and before rupture of membranes; late diagnosis of HIV-1 infection; lack of intrapartum antiretrovirals; and incomplete avoidance of breastfeeding. Conclusion: Early knowledge of HIV-1 infection status (ideally before or in early pregnancy) would aid timely initiation of antiretroviral treatment and strategies designed to prevent mother-to-child transmission. Use of antiretrovirals must be appropriately monitored in terms of adherence and drug resistance. If feasible, breastfeeding should be completely avoided. Presented in part at the XIX International AIDS Conference (Washington, DC; July 22-27, 2012); abstract WEPE163. (c) 2012 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics.

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Abstract Background Regardless the regulatory function of microRNAs (miRNA), their differential expression pattern has been used to define miRNA signatures and to disclose disease biomarkers. To address the question of whether patients presenting the different types of diabetes mellitus could be distinguished on the basis of their miRNA and mRNA expression profiling, we obtained peripheral blood mononuclear cell (PBMC) RNAs from 7 type 1 (T1D), 7 type 2 (T2D), and 6 gestational diabetes (GDM) patients, which were hybridized to Agilent miRNA and mRNA microarrays. Data quantification and quality control were obtained using the Feature Extraction software, and data distribution was normalized using quantile function implemented in the Aroma light package. Differentially expressed miRNAs/mRNAs were identified using Rank products, comparing T1DxGDM, T2DxGDM and T1DxT2D. Hierarchical clustering was performed using the average linkage criterion with Pearson uncentered distance as metrics. Results The use of the same microarrays platform permitted the identification of sets of shared or specific miRNAs/mRNA interaction for each type of diabetes. Nine miRNAs (hsa-miR-126, hsa-miR-1307, hsa-miR-142-3p, hsa-miR-142-5p, hsa-miR-144, hsa-miR-199a-5p, hsa-miR-27a, hsa-miR-29b, and hsa-miR-342-3p) were shared among T1D, T2D and GDM, and additional specific miRNAs were identified for T1D (20 miRNAs), T2D (14) and GDM (19) patients. ROC curves allowed the identification of specific and relevant (greater AUC values) miRNAs for each type of diabetes, including: i) hsa-miR-1274a, hsa-miR-1274b and hsa-let-7f for T1D; ii) hsa-miR-222, hsa-miR-30e and hsa-miR-140-3p for T2D, and iii) hsa-miR-181a and hsa-miR-1268 for GDM. Many of these miRNAs targeted mRNAs associated with diabetes pathogenesis. Conclusions These results indicate that PBMC can be used as reporter cells to characterize the miRNA expression profiling disclosed by the different diabetes mellitus manifestations. Shared miRNAs may characterize diabetes as a metabolic and inflammatory disorder, whereas specific miRNAs may represent biological markers for each type of diabetes, deserving further attention.

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Global dengue virus spread in tropical and sub-tropical regions has become a major international public health concern. It is evident that DENV genetic diversity plays a significant role in the immunopathology of the disease and that the identification of polymorphisms associated with adaptive responses is important for vaccine development. The investigation of naturally occurring genomic variants may play an important role in the comprehension of different adaptive strategies used by these mutants to evade the human immune system. In order to elucidate this role we sequenced the complete polyprotein-coding region of thirty-three DENV-3 isolates to characterize variants circulating under high endemicity in the city of São José de Rio Preto, Brazil, during the onset of the 2006-07 epidemic. By inferring the evolutionary history on a local-scale and estimating rates of synonymous (dS) and nonsynonimous (dN) substitutions, we have documented at least two different introductions of DENV-3 into the city and detected 10 polymorphic codon sites under significant positive selection (dN/dS > 1) and 8 under significant purifying selection (dN/dS < 1). We found several polymorphic amino acid coding sites in the envelope (15), NS1 (17), NS2A (11), and NS5 (24) genes, which suggests that these genes may be experiencing relatively recent adaptive changes. Furthermore, some polymorphisms correlated with changes in the immunogenicity of several epitopes. Our study highlights the existence of significant and informative DENV variability at the spatio-temporal scale of an urban outbreak.