909 resultados para HIV-1 reverse transcriptase


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The Leishmania amazonensis telomerase gene was cloned by a polymerase chain reaction-based strategy using primers designed from a Leishmania major sequence that shared similarities with conserved telomerase motifs. The genes from three other species were cloned for comparative purposes. A ClustalW multiple-sequence alignment demonstrated that the Leishmania telomerases show greater homology with each other than with the proteins of other kinetoplastids and eukaryotes. Characterization experiments indicated that the putative Leishmania telomerase gene was probably in single copy and located in the largest chromosomes. A single messenger ribonucleic acid transcript was found in promastigotes. Phylogenetic analysis suggested that Leishmania telomerase might represent a liaison between the oldest and the newest branches of telomerases.

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Highly active antiretroviral therapy (HAART) has lead to a dramatic decrease in the morbidity of patients infected with HIV. However, metabolic side effects, including lipodystrophy and dyslipidemia, have been reported in patients treated with antiretroviral therapy (HAART). The aim of this study was to analyze the clinical and metabolic alterations and the cytokines TNF-α, IFN-γ, IL-2, IL-10 and TNF-II receptors profile in the serum of treated HIV-1-infected individuals with or without lipodystrophy. Eighty-four adult patients were analyzed, 42 females and 42 males, their mean age was 37 years old, and they received HAART for at least 15 months. These patients were ambulatory outpatients from the Infectious and Parasitary Disease Area of Botucatu School of Medicine, UNESP. Subsequently the individuals were distributed into 2 groups, G1: 42 HIV-infected individuals with lipodystrophy, and G2: 42 HIV-infected individuals without lipodystrophy. Among the antiretrovirals used, stavudine was more associated to the lipodystrophy group and zidovudine to the group without lipodystrophy. CD4, CD8, viral load, glucose, albumin, and the circulating lipid did not present any difference in the group comparison, except for triglyceride that was elevated in the lipodystrophy group and HDL which was present in low concentration in more patients of G1. The cytokines TNF-α, TNF-RII, and IL-10 profile presented high levels in the lipodystrophy group; also it was positively correlated with this group. On the other hand, IL-2 and IFN-γ presented low levels in this group. High levels of TNF-α and its receptor seem to be associated to the development of lipodystrophy in patients receiving HAART.

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The intestinal microbiota consists of a qualitatively and quantitatively diverse range of microorganisms dynamically interacting with the host. It is remarkably stable with regard to the presence of microorganisms and their roles which, however, can be altered due to pathological conditions, diet composition, gastrointestinal disturbances and/or drug ingestion. The present review aimed at contributing to the discussion about changes in the intestinal microbiota due to HIV-1 infection, focusing on the triad infection-microbiota-nutrition as factors that promote intestinal bacterial imbalance. Intestinal microbiota alterations can be due to the HIV-1 infection as a primary factor or the pharmacotherapy employed, or they can be one of the consequences of the disease.

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The extensive use of Highly Active Antiretroviral Therapy (HAART) has transformed HIV infection into a chronic condition. Thus, metabolic alterations including lipodystrophy and dyslipidemia have been associated with the use of such medications. The objective of the present study was to analyze clinical metabolic alterations and the profile of TNF-α, IFN-γ, IL-2, IL-10, and TNF-α type II soluble receptor in serum of HIV-1 individuals with and without lipodystrophy. Eighty-four adults were evaluated, 42 males and 42 females, mean age 37 years, and HAART time of at least 15 months. Two groups were formed, G1: 42 individuals with lipodystrophy, and G2: 42 without lipodistropy. From the HAART used, stavudine was more associated with the lipodystrophy group and zidovudine with the non-lipodystrophy group. CD4 and CD8 values, viral load, glucose, albumin, and lipids were not different between groups, except for triglycerides, which were high in the lipodystrophy group, and HDL, whose concentration was reduced in G1. TNF-α, TNF-RII, and IL-10 profiles were high and had positive correlation; IL-2 and IFN-γ had reduced levels in the lipodystrophy group. High TNF-α and its receptor levels seem to be associated with lipodystrophy development in individuals under HAART therapy.

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Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light- to dark-brown macules on sun-exposed skin areas. The literature shows few studies on its physiopathogeny. However, changes in α-melanocyte stimulating hormone (α-MSH) secretion and melanocortin-1 receptor (MC1-R) expression may play a role to trigger this condition. Biopsies were taken from both melasma skin and adjacent perilesional normal skin of 44 patients. The biopsies were submitted for hematoxylin and eosin and Fontana-Masson staining and immunohistochemistry with Melan-A, α-MSH, and MC1-R, and processed for transmission electron microscopy. In some cases, they were submitted to MC1-R gene expression analysis by real-time polymerase chain reaction. Increased lymphohistiocytic infiltrate and solar elastosis, higher epidermal melanin were observed in melasma skin. Electron microscopy revealed a greater number of mature melanosomes in keratinocytes and melanocytes, and more prominent cytoplasmic organelles in melasma skin. There was no difference in melanocyte number between areas. However, melanocytes were larger and more dendritic in melasma skin. Immunohistochemistry with α-MSH and MC1-R showed significant labeling in melasmic epidermis but MC1-R messenger ribonucleic acid (RNAm) did not show significant quantitative difference between melasma and normal skin. © 2010 by Lippincott Williams & Wilkins.

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Combination Antiretroviral Therapy (cART) aims to inhibit viral replication, delay immunodeficiency progression and improve survival in AIDS patients. The objective of this study was to compare two different schemes of cART, based on plasma viral load (VL) and CD4+ T lymphocyte count, during 48 weeks of treatment. For this purpose, 472 medical charts of a Specialized Outpatient Service were reviewed from 1998 to 2005. Out of these, 58 AIDS patients who had received a triple drug scheme as the initial treatment were included in the study and two groups were formed: Group 1 (G1): 47 individuals treated with two nucleoside reverse-transcriptase inhibitors (NRTI) and one non-nucleoside reverse-transcriptase inhibitor; Group 2 (G2): 11 patients treated with two NRTI and one protease inhibitor. In G1 and G2, 53.2% and 81.8% respectively were patients with an AIDS-defining disease. The T CD4+ lymphocyte count increased progressively up until the 24th week of treatment in all patients, while VL became undetectable in 68.1% of G1 and in 63.6% of G2. The study concluded that the evolutions of laboratory tests were similar in the two treatment groups and that both presented a favorable clinical evolution.

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Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

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Pós-graduação em Microbiologia - IBILCE

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Host genetic factors play an important role in mediating resistance to HIV-1 infection and may modify the course of infection. HLA-B alleles (Bw4 epitope; B*27 and B*57) as well as killer cell immunoglobulin-like receptors have been associated with slow progression of HIV-1 infection. OBJECTIVE: To evaluate the association between serological epitopes HLA-Bw4 and HLA-Bw6 and prognostic markers in AIDS. METHODS: 147 HIV-infected individuals in Bahia, Northeast Brazil, were genotyped for HLA class I locus. HLA class I genotyping was performed by hybridization with sequence-specific oligonucleotide probes following amplification of the corresponding HLA-A, HLA-B and HLA-C genes. Statistical analysis was performed using Fisher's exact and ANOVA tests for categorical and continuous variables, respectively. RESULTS: We detected a significant association (χ2 = 4.856; p = 0.018) between the presence of HLA-Bw4 and low levels of viremia. Eighteen out of the 147 HIV-infected individuals presented viremia <1,800 copies/mL and 129 presented viremia > 2,000 copies/mL. Ninety and four percent (17/18) of all individuals with viremia < 1,800 copies/mL carried HLA-Bw4, compared to 67.4% (87/129) of individuals with viremia > 2,000 copies/mL. Additionally, we found a significantly higher frequency of B*57 (OR = 13.94; 95% CI = 4.19-46.38; p < 0.0001) and Cw*18 (OR = 16.15; 95% CI = 3.46-75.43; p < 0.0001) alleles, favoring the group with lower viremia levels, in comparison with those with higher viral load. CONCLUSION: HLA-Bw4-B*57 and Cw*18 alleles are associated with lower level of viral load in HIV-infected Brazilian patients. These findings may help us in understanding the determinants of HIV evolution in Brazilian patients, as well as in providing important information on immune response correlates of protection for such population.

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INTRODUÇÃO: O presente estudo investigou a associação entre o polimorfismo no gene da lectina ligante de manose (MBL) e os níveis séricos da proteína com a infecção pelo HIV-1. MÉTODOS: As amostras de sangue (5mL) foram coletadas de 97 indivíduos infectados pelo HIV-1 residentes em Belém, Estado do Pará, Brasil, que frequentavam a Unidade de Referência Especial para Doenças Infecciosas e Parasitárias Especiais (URE-DIPE). Os níveis de linfócitos T CD4+ e da carga viral plasmática foram quantificados. Um fragmento de 349pb do exon 1 da MBL foi amplificado via PCR, utilizando DNA genômico extraído das amostras controles e dos indivíduos portadores do HIV-1, seguindo protocolos previamente estabelecidos. O nível plasmático de MBL nos pacientes foi quantificado usando kit de ensaio imunoenzimático. RESULTADOS: Dois alelos foram observados - MBL*O, com uma frequência de 26,3% em indivíduos infectados e o alelo selvagem MBL*A (73,7%). Frequências similares foram observadas no grupo controle (p > 0,05). As frequências genotípicas estavam em equilíbrio de Hardy-Weinberg em ambos os grupos. A média dos níveis plasmáticos MBL variou por genótipo, com diferenças significativas entre os genótipos AA e AO (p < 0,0001), e AA e OO (p < 0,001), mas não entre AO e OO (p=0,17). Além disso, os linfócitos T CD4+ e os níveis plasmáticos de carga viral não diferiram significativamente de acordo com o genótipo (p>0,05). CONCLUSÕES: Os resultados deste estudo não apoiam a hipótese de que o polimorfismo no gene MBL ou baixa concentração plasmática de MBL poderia ter uma influência direta sobre a infecção pelo HIV-1, embora um estudo com número maior de pacientes seja necessário.

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ABSTRACT: The occurrence of HTLV-I/II and HIV-1 coinfections have been shown to be frequent, probably in consequence of their similar modes of transmission. This paper presents the prevalence of coinfection of HTLV among HIV-1 infected and AIDS patients in Belém, State of Pará, Brazil. A group of 149 patients attending the AIDS Reference Unit of the State Department of Health was tested for the presence of antibodies to HTLV-I/II using an enzyme immunoassay and the positive reactions were confirmed with a Western blot that discriminates between HTLV-I and HTLV-II infections. Four patients (2.7%) were positive to HTLV-I, seven (4.7%) to HTLV-II and one (0.7%) showed an indeterminate pattern of reaction. The present results show for the first time in Belém not only the occurrence of HTLV-II/HIV-1 coinfections but also a higher prevalence of HTLV-II in relation to HTLV-I. Furthermore, it also enlarges the geographical limits of the endemic area for HTLV-II in the Amazon region of Brazil.