Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 592
Filtrar
1.
Virol J ; 21(1): 47, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38395987

RESUMO

HIV infection compromises both the peripheral and central immune systems due to its pathogenic and neuropathogenic features. The mechanisms driving HIV-1 pathogenesis and neuropathogenesis involve a series of events, including metabolic dysregulation. Furthermore, HIV-subtype-specific variations, particularly alterations in the amino acid sequences of key viral proteins, are known to influence the severity of clinical outcomes in people living with HIV. However, the impact of amino acid sequence variations in specific viral proteins, such as Viral protein R (Vpr), on metabolites within the Tryptophan (Trp)-kynurenine (Kyn) pathway in people living with HIV remains unclear. Our research aimed to explore the relationship between variations in the Vpr amino acid sequence (specifically at positions 22, 41, 45, and 55, as these have been previously linked to neurocognitive function) and peripheral Trp-Kyn metabolites. Additionally, we sought to clarify the systems biology of Vpr sequence variation by examining the link between Trp-Kyn metabolism and peripheral inflammation, as a neuropathogenic mechanism. In this preliminary study, we analyzed a unique cohort of thirty-two (n = 32) South African cART naïve people living with HIV. We employed Sanger sequencing to ascertain blood-derived Vpr amino acid sequence variations and a targeted LC-MS/MS metabolomics platform to assess Trp-Kyn metabolites, such as Trp, Kyn, kynurenic acid (KA), and quinolinic acid (QUIN). Particle-enhanced turbidimetric assay and Enzyme-linked immunosorbent assays were used to measure immune markers, hsCRP, IL-6, suPAR, NGAL and sCD163. After applying Bonferroni corrections (p =.05/3) and adjusting for covariates (age and sex), only the Vpr G41 and A55 groups was nearing significance for higher levels of QUIN compared to the Vpr S41 and T55 groups, respectively (all p =.023). Multiple regression results revealed that Vpr amino acid variations at position 41 (adj R2 = 0.049, ß = 0.505; p =.023), and 55 (adj R2 = 0.126, ß = 0.444; p =.023) displayed significant associations with QUIN after adjusting for age and sex. Lastly, the higher QUIN levels observed in the Vpr G41 group were found to be correlated with suPAR (r =.588, p =.005). These results collectively underscore the importance of specific Vpr amino acid substitutions in influencing QUIN and inflammation (specifically suPAR levels), potentially contributing to our understanding of their roles in the pathogenesis and neuropathogenesis of HIV-1.


Assuntos
Produtos do Gene vpr , Infecções por HIV , Soropositividade para HIV , HIV-1 , Humanos , Triptofano/metabolismo , Cinurenina/metabolismo , HIV-1/genética , HIV-1/metabolismo , Sequência de Aminoácidos , Infecções por HIV/complicações , Cromatografia Líquida , Projetos Piloto , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Espectrometria de Massas em Tandem , Inflamação
2.
Kidney Int ; 103(3): 529-543, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36565808

RESUMO

Chronic kidney disease (CKD) is a common cause of morbidity in human immunodeficiency virus (HIV)-positive individuals. HIV infection leads to a wide spectrum of kidney cell damage, including tubular epithelial cell (TEC) injury. Among the HIV-1 proteins, the pathologic effects of viral protein R (Vpr) are well established and include DNA damage response, cell cycle arrest, and cell death. Several in vitro studies have unraveled the molecular pathways driving the cytopathic effects of Vpr in tubular epithelial cells. However, the in vivo effects of Vpr on tubular injury and CKD pathogenesis have not been thoroughly investigated. Here, we use a novel inducible tubular epithelial cell-specific Vpr transgenic mouse model to show that Vpr expression leads to progressive tubulointerstitial damage, interstitial inflammation and fibrosis, and tubular cyst development. Importantly, Vpr-expressing tubular epithelial cells displayed significant hypertrophy, aberrant cell division, and atrophy; all reminiscent of tubular injuries observed in human HIV-associated nephropathy (HIVAN). Single-cell RNA sequencing analysis revealed the Vpr-mediated transcriptomic responses in specific tubular subsets and highlighted the potential multifaceted role of p53 in the regulation of cell metabolism, proliferation, and death pathways in Vpr-expressing tubular epithelial cells. Thus, our study demonstrates that HIV Vpr expression in tubular cells is sufficient to induce HIVAN-like tubulointerstitial damage and fibrosis, independent of glomerulosclerosis and proteinuria. Additionally, as this new mouse model develops progressive CKD with diffuse fibrosis and kidney failure, it can serve as a useful tool to examine the mechanisms of kidney disease progression and fibrosis in vivo.


Assuntos
Nefropatia Associada a AIDS , Produtos do Gene vpr , Infecções por HIV , HIV-1 , Insuficiência Renal Crônica , Animais , Humanos , Camundongos , Nefropatia Associada a AIDS/genética , Modelos Animais de Doenças , Produtos do Gene vpr/genética , Produtos do Gene vpr/metabolismo , Produtos do Gene vpr/farmacologia , Infecções por HIV/complicações , HIV-1/genética , HIV-1/metabolismo , Proteínas do Vírus da Imunodeficiência Humana , Camundongos Transgênicos , Insuficiência Renal Crônica/complicações
3.
J Gen Virol ; 103(10)2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36205476

RESUMO

Macaque-tropic HIV-1 (HIV-1mt) variants have been developed to establish preferable primate models that are advantageous in understanding HIV-1 infection pathogenesis and in assessing the preclinical efficacy of novel prevention/treatment strategies. We previously reported that a CXCR4-tropic HIV-1mt, MN4Rh-3, efficiently replicates in peripheral blood mononuclear cells (PBMCs) of cynomolgus macaques homozygous for TRIMCyp (CMsTC). However, the CMsTC challenged with MN4Rh-3 displayed low viral loads during the acute infection phase and subsequently exhibited short-term viremia. These virological phenotypes in vivo differed from those observed in most HIV-1-infected people. Therefore, further development of the HIV-1mt variant was needed. In this study, we first reconstructed the MN4Rh-3 clone to produce a CCR5-tropic HIV-1mt, AS38. In addition, serial in vivo passages allowed us to produce a highly adapted AS38-derived virus that exhibits high viral loads (up to approximately 106 copies ml-1) during the acute infection phase and prolonged periods of persistent viremia (lasting approximately 16 weeks postinfection) upon infection of CMsTC. Whole-genome sequencing of the viral genomes demonstrated that the emergence of a unique 15-nt deletion within the vif gene was associated with in vivo adaptation. The deletion resulted in a significant increase in Vpr protein expression but did not affect Vif-mediated antagonism of antiretroviral APOBEC3s, suggesting that Vpr is important for HIV-1mt adaptation to CMsTC. In summary, we developed a novel CCR5-tropic HIV-1mt that can induce high peak viral loads and long-term viremia and exhibits increased Vpr expression in CMsTC.


Assuntos
Produtos do Gene vpr , Infecções por HIV , Soropositividade para HIV , HIV-1 , Vírus da Imunodeficiência Símia , Animais , HIV-1/genética , Leucócitos Mononucleares , Macaca fascicularis , Vírus da Imunodeficiência Símia/genética , Viremia , Replicação Viral
4.
PLoS One ; 17(9): e0273313, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36129874

RESUMO

HIV-associated nephropathy (HIVAN) impairs functions of both glomeruli and tubules. Attention has been previously focused on the HIVAN glomerulopathy. Tubular injury has drawn increased attention because sodium wasting is common in hospitalized HIV/AIDS patients. We used viral protein R (Vpr)-transgenic mice to investigate the mechanisms whereby Vpr contributes to urinary sodium wasting. In phosphoenolpyruvate carboxykinase promoter-driven Vpr-transgenic mice, in situ hybridization showed that Vpr mRNA was expressed in all nephron segments, including the distal convoluted tubule. Vpr-transgenic mice, compared with wild-type littermates, markedly increased urinary sodium excretion, despite similar plasma renin activity and aldosterone levels. Kidneys from Vpr-transgenic mice also markedly reduced protein abundance of the Na+-Cl- cotransporter (NCC), while mineralocorticoid receptor (MR) protein expression level was unchanged. In African green monkey kidney cells, Vpr abrogated the aldosterone-mediated stimulation of MR transcriptional activity. Gene expression of Slc12a3 (NCC) in Vpr-transgenic mice was significantly lower compared with wild-type mice, assessed by both qRT-PCR and RNAScope in situ hybridization analysis. Chromatin immunoprecipitation assays identified multiple MR response elements (MRE), located from 5 kb upstream of the transcription start site and extending to the third exon of the SLC12A3 gene. Mutation of MRE and SP1 sites in the SLC12A3 promoter region abrogated the transcriptional responses to aldosterone and Vpr, indicating that functional MRE and SP1 are required for the SLC12A3 gene suppression in response to Vpr. Thus, Vpr attenuates MR transcriptional activity and inhibits Slc12a3 transcription in the distal convoluted tubule and contributes to salt wasting in Vpr-transgenic mice.


Assuntos
Produtos do Gene vpr , HIV-1 , Aldosterona/metabolismo , Aldosterona/farmacologia , Animais , Chlorocebus aethiops , Produtos do Gene vpr/metabolismo , HIV-1/genética , Túbulos Renais Distais/metabolismo , Camundongos , Camundongos Transgênicos , Fosfoenolpiruvato , RNA Mensageiro/metabolismo , Receptores de Mineralocorticoides/genética , Receptores de Mineralocorticoides/metabolismo , Renina/metabolismo , Sódio/metabolismo , Cloreto de Sódio/metabolismo , Simportadores de Cloreto de Sódio/metabolismo , Membro 3 da Família 12 de Carreador de Soluto/genética , Membro 3 da Família 12 de Carreador de Soluto/metabolismo , Tiazidas
5.
PLoS Pathog ; 17(8): e1009775, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34339457

RESUMO

Viruses have evolved means to manipulate the host's ubiquitin-proteasome system, in order to down-regulate antiviral host factors. The Vpx/Vpr family of lentiviral accessory proteins usurp the substrate receptor DCAF1 of host Cullin4-RING ligases (CRL4), a family of modular ubiquitin ligases involved in DNA replication, DNA repair and cell cycle regulation. CRL4DCAF1 specificity modulation by Vpx and Vpr from certain simian immunodeficiency viruses (SIV) leads to recruitment, poly-ubiquitylation and subsequent proteasomal degradation of the host restriction factor SAMHD1, resulting in enhanced virus replication in differentiated cells. To unravel the mechanism of SIV Vpr-induced SAMHD1 ubiquitylation, we conducted integrative biochemical and structural analyses of the Vpr protein from SIVs infecting Cercopithecus cephus (SIVmus). X-ray crystallography reveals commonalities between SIVmus Vpr and other members of the Vpx/Vpr family with regard to DCAF1 interaction, while cryo-electron microscopy and cross-linking mass spectrometry highlight a divergent molecular mechanism of SAMHD1 recruitment. In addition, these studies demonstrate how SIVmus Vpr exploits the dynamic architecture of the multi-subunit CRL4DCAF1 assembly to optimise SAMHD1 ubiquitylation. Together, the present work provides detailed molecular insight into variability and species-specificity of the evolutionary arms race between host SAMHD1 restriction and lentiviral counteraction through Vpx/Vpr proteins.


Assuntos
Proteínas Culina/química , Produtos do Gene vpr/metabolismo , Complexo de Endopeptidases do Proteassoma/química , Proteína 1 com Domínio SAM e Domínio HD/química , Ubiquitinação , Replicação Viral , Sequência de Aminoácidos , Animais , Microscopia Crioeletrônica , Proteínas Culina/metabolismo , Produtos do Gene vpr/genética , Proteína NEDD8/química , Proteína NEDD8/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteína 1 com Domínio SAM e Domínio HD/metabolismo , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo
6.
Chem Biodivers ; 18(10): e2100401, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34415099

RESUMO

A new menthane-type monoterpene, alpigalanol (1), together with four known terpenes (2-5) were isolated from the ethyl acetate soluble fraction of the 70 % ethanol extract of the Alpinia galanga rhizomes. The structure of 1 was determined by spectroscopic analyses, including 1D- and 2D-NMR. The extract of the A. galanga rhizomes and all isolated compounds (1-5) possessed Vpr inhibitory activities against the TREx-HeLa-Vpr cells at a concentration of 1.25 µM without showing any cytotoxicity.


Assuntos
Alpinia/química , Produtos do Gene vpr/antagonistas & inibidores , Monoterpenos/farmacologia , Rizoma/química , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Conformação Molecular , Monoterpenos/química , Monoterpenos/isolamento & purificação , Células Tumorais Cultivadas
7.
Fitoterapia ; 151: 104870, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33652075

RESUMO

Six new isopimarane diterpenoids, shanpanootols A-F (1-6), along with two known analogues, were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Myanmar. The structures of these compounds were elucidated by extensive spectroscopic techniques such as 1D and 2D NMR and HRESIMS. The absolute configuration of 1 was determined by the modified Mosher method. The new isolates (1-6) were tested for their Vpr inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootols C (3) and E (5) inhibited Vpr at doses of 2.5 and 5 µM, respectively.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Diterpenos/farmacologia , Zingiberaceae/química , Antineoplásicos Fitogênicos/isolamento & purificação , Diterpenos/isolamento & purificação , Produtos do Gene vpr/antagonistas & inibidores , Células HeLa , Humanos , Estrutura Molecular , Mianmar , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Rizoma/química
8.
J Nat Med ; 74(3): 571-578, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32328863

RESUMO

Three new quassinoids, javanicinols A and B (1 and 2) and 4-keto-(16S)-methoxyjavanicin B (3), together with three known quassinoids (4-6) were isolated from the chloroform-soluble fraction of the methanol extract of the Picrasma javanica wood. The structures of 1-3 were determined by spectroscopic analyses, including 1D and 2D NMR, HRESIMS, and CD. The anti-HIV-1 viral protein R (Vpr) assay revealed that 1 and 2 exhibited potent anti-Vpr activities at 1.25 µM. Furthermore, the assay also revealed the potent anti-Vpr activities of (16R)-methoxyjavanicin B (7) and (16S)-methoxyjavanicin B (8), which were previously isolated from the Picrasma javanica wood.


Assuntos
Fármacos Anti-HIV/farmacologia , Produtos do Gene vpr/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Picrasma/química , Quassinas/farmacologia , Fármacos Anti-HIV/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Quassinas/química , Quassinas/isolamento & purificação , Madeira/química
9.
Viruses ; 12(1)2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952107

RESUMO

Viral protein R (Vpr) is an accessory protein found in various primate lentiviruses, including human immunodeficiency viruses type 1 and 2 (HIV-1 and HIV-2) as well as simian immunodeficiency viruses (SIVs). Vpr modulates many processes during viral lifecycle via interaction with several of cellular targets. Previous studies showed that HIV-1 Vpr strengthened degradation of Mini-chromosome Maintenance Protein10 (MCM10) by manipulating DCAF1-Cul4-E3 ligase in proteasome-dependent pathway. However, whether Vpr from other primate lentiviruses are also associated with MCM10 degradation and the ensuing impact remain unknown. Based on phylogenetic analyses, a panel of primate lentiviruses Vpr/x covering main virus lineages was prepared. Distinct MCM10 degradation profiles were mapped and HIV-1, SIVmus and SIVrcm Vprs induced MCM10 degradation in proteasome-dependent pathway. Colocalization and interaction between MCM10 with these Vprs were also observed. Moreover, MCM10 2-7 interaction region was identified as a determinant region susceptible to degradation. However, MCM10 degradation did not alleviate DNA damage response induced by these Vpr proteins. MCM10 degradation by HIV-1 Vpr proteins was correlated with G2/M arrest, while induction of apoptosis and oligomerization formation of Vpr failed to alter MCM10 proteolysis. The current study demonstrated a distinct interplay pattern between primate lentiviruses Vpr proteins and MCM10.


Assuntos
Produtos do Gene vpr/metabolismo , Lentivirus de Primatas/genética , Proteínas de Manutenção de Minicromossomo/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Pontos de Checagem do Ciclo Celular , Dano ao DNA , Produtos do Gene vpr/genética , Células HEK293 , HIV-1/genética , HIV-1/fisiologia , Células HeLa , Humanos , Lentivirus de Primatas/química , Proteínas de Manutenção de Minicromossomo/genética , Filogenia , Proteólise , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/fisiologia
10.
J Virol ; 94(4)2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-31776272

RESUMO

The human immunodeficiency virus type 1 (HIV-1) accessory protein Vpr enhances viral replication in both macrophages and, to a lesser extent, cycling T cells. Virion-packaged Vpr is released in target cells shortly after entry, suggesting it is required in the early phase of infection. Previously, we described REAF (RNA-associated early-stage antiviral factor; RPRD2), a constitutively expressed protein that potently restricts HIV replication at or during reverse transcription. Here, we show that a virus without an intact vpr gene is more highly restricted by REAF and, using delivery by virus-like particles (VLPs), that Vpr alone is sufficient for REAF degradation in primary macrophages. REAF is more highly expressed in macrophages than in cycling T cells, and we detected, by coimmunoprecipitation assay, an interaction between Vpr protein and endogenous REAF. Vpr acts quickly during the early phase of replication and induces the degradation of REAF within 30 min of viral entry. Using Vpr F34I and Q65R viral mutants, we show that nuclear localization and interaction with cullin 4A-DBB1 (DCAF1) E3 ubiquitin ligase are required for REAF degradation by Vpr. In response to infection, cells upregulate REAF levels. This response is curtailed in the presence of Vpr. These findings support the hypothesis that Vpr induces the degradation of a factor, REAF, that impedes HIV infection in macrophages.IMPORTANCE For at least 30 years, it has been known that HIV-1 Vpr, a protein carried in the virion, is important for efficient infection of primary macrophages. Vpr is also a determinant of the pathogenic effects of HIV-1 in vivo A number of cellular proteins that interact with Vpr have been identified. So far, it has not been possible to associate these proteins with altered viral replication in macrophages or to explain why Vpr is carried in the virus particle. Here, we show that Vpr mitigates the antiviral effects of REAF, a protein highly expressed in primary macrophages and one that inhibits virus replication during reverse transcription. REAF is degraded by Vpr within 30 min of virus entry in a manner dependent on the nuclear localization of Vpr and its interaction with the cell's protein degradation machinery.


Assuntos
Antivirais/metabolismo , HIV-1/metabolismo , Replicação Viral/fisiologia , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/fisiologia , Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/metabolismo , Produtos do Gene vpr/metabolismo , Produtos do Gene vpr/fisiologia , Células HEK293 , Infecções por HIV/virologia , HIV-1/fisiologia , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Macrófagos/metabolismo , Cultura Primária de Células , Ubiquitina-Proteína Ligases/metabolismo , Vírion/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo
11.
Cells ; 8(11)2019 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-31652959

RESUMO

Vpr is a lentiviral accessory protein that is expressed late during the infection cycle and is packaged in significant quantities into virus particles through a specific interaction with the P6 domain of the viral Gag precursor. Characterization of the physiologically relevant function(s) of Vpr has been hampered by the fact that in many cell lines, deletion of Vpr does not significantly affect viral fitness. However, Vpr is critical for virus replication in primary macrophages and for viral pathogenesis in vivo. It is generally accepted that Vpr does not have a specific enzymatic activity but functions as a molecular adapter to modulate viral or cellular processes for the benefit of the virus. Indeed, many Vpr interacting factors have been described by now, and the goal of this review is to summarize our current knowledge of cellular proteins targeted by Vpr.


Assuntos
Produtos do Gene vpr/metabolismo , Genes vpr/genética , Genes vpr/fisiologia , Sequência de Aminoácidos , Linhagem Celular , Humanos , Vírion/metabolismo , Replicação Viral/genética , Replicação Viral/fisiologia , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
12.
J Biosci Bioeng ; 128(4): 445-449, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31076338

RESUMO

Viral protein R (Vpr) is a small, basic accessory protein (14 kDa) that is well conserved in Human immunodeficiency virus-1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). Numerous investigations over the past 2 decades have suggested that Vpr would be an attractive target for HIV disease treatment. Small molecules, including fumagillin, damnacanthal, quercetin, vipirinin, isopimarane diterpenoids, picrasane quassinoids, iridoids, and bis-iridoid glycosides, have been reported as potent Vpr inhibitors. These compounds may not only represent HIV drug seeds, but also could be new target compounds for biochemical synthesis such as current synthetic biology and enzyme bioengineering approaches, due to their anti-Vpr activities. In our investigations of different types of compounds with Vpr inhibitory activity, we found that the CHCl3 soluble, crude extract of the whole Swertia chirata plant inhibited the expression of Vpr in Hela cells harboring the TREx plasmid encoding full-length Vpr (TREx-HeLa-Vpr cells). The purification and isolation of the active CHCl3 soluble portion afforded six secondary metabolites, including four xanthone derivatives, decussatine (1), methylswertianin (2), 1-hydroxy-3,5-dimethoxyxanthone (3), and bellidifolin (4), and two triterpenoids, oleanolic acid (5) and 12-hydroxyoleanolic lactone (6). The evaluation of the anti-Vpr activities of 1, 2, and 4-6 against TREx-HeLa-Vpr cells revealed that 4 and 5 are potent Vpr inhibitors with an effective dose of 10 µM, and are chemically and structurally distinct from previously reported inhibitors.


Assuntos
Produtos do Gene vpr/antagonistas & inibidores , Swertia/química , Antivirais/farmacologia , Células HeLa , Humanos , Xantonas/farmacologia
13.
Sci Rep ; 9(1): 3937, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30850685

RESUMO

The discovery of tumor-associated antigens recognized by T lymphocytes opens the possibility of vaccinating cancer patients with defined antigens. However, one of the major limitation of peptide-based vaccines is the low immunogenicity of antigenic peptides. Interestingly, if these epitopes are directly delivered into the cytoplasm of antigen presenting cells, they can be efficiently presented via the direct MHC class I presentation pathway. To improve antigen entry, one promising approach is the use of cell penetrating peptides (CPPs). However, most studies use a covalent binding of the CPP with the antigen. In the present study, we focused on the C-terminal domain of Vpr which was previously demonstrated to efficiently deliver plasmid DNA into cells. We provide evidence that the peptides Vpr55-91 and Vpr55-82 possess the capacity of delivering proteins and epitopes into cell lines as well as into human primary dendritic cells, without the necessicity for a chemical linkage. Moreover, immunization of HLA-A2 transgenic mice with Vpr55-91 as the sole adjuvant is able to induce antigen-specific cytotoxic T lymphocytes against multiple tumor epitopes.


Assuntos
Peptídeos Penetradores de Células/imunologia , Produtos do Gene vpr/imunologia , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Animais , Apresentação de Antígeno/imunologia , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Células CHO , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Linhagem Celular , Peptídeos Penetradores de Células/genética , Cricetulus , Sistemas de Liberação de Medicamentos , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Produtos do Gene vpr/genética , Antígeno HLA-A2/genética , Antígeno HLA-A2/imunologia , Células Hep G2 , Humanos , Camundongos , Camundongos Transgênicos , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Transporte Proteico , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia
14.
Fitoterapia ; 134: 101-107, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30794917

RESUMO

Four new bis-iridoid glycosides, saungmaygaosides A-D (1-4), and six known iridoid glycosides (5-10) were isolated from the n-butanol extract of the stems of Picrorhiza kurroa collected in Myanmar. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were assayed for anti-Vpr activity, using TREx-HeLa-Vpr cells. Among the isolates, saungmaygaoside D (4), sylvestroside IV dimethyl acetal (7), and sweroside (8) were the most potent inhibitors with effective doses of 5 and 10 µM, respectively, without showing any notable cytotoxicities.


Assuntos
Antivirais/farmacologia , Produtos do Gene vpr/antagonistas & inibidores , Glicosídeos Iridoides/farmacologia , Picrorhiza/química , Antivirais/isolamento & purificação , Células HeLa , Humanos , Glicosídeos Iridoides/isolamento & purificação , Estrutura Molecular , Mianmar , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Caules de Planta/química
15.
Nat Microbiol ; 3(12): 1354-1361, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30297740

RESUMO

Host factors that silence provirus transcription in CD4+ memory T cells help HIV-1 escape eradication by the host immune system and by antiviral drugs1. These same factors, however, must be overcome for HIV-1 to propagate. Here we show that Vpx and Vpr encoded by diverse primate immunodeficiency viruses activate provirus transcription. Vpx and Vpr are adaptor proteins for the DCAF1-CUL4A/B E3 ubiquitin ligase that degrade SAMHD1 and increase reverse transcription2-4. Nonetheless, Vpx and Vpr have effects on reporter gene expression that are not explained by SAMHD1 degradation5-8. A screen for factors that mimic these effects identified the human silencing hub (HUSH) complex, FAM208A (TASOR/RAP140), MPHOSPH8 (MPP8), PPHLN1 (PERIPHILIN) and MORC29-13. Vpx associated with the HUSH complex and decreased steady-state level of these proteins in a DCAF1/CUL4A/B/proteasome-dependent manner14,15. Replication kinetics of HIV-1 and SIVMAC was accelerated to a similar extent by vpx or FAM208A knockdown. Finally, vpx increased steady-state levels of LINE-1 ORF1p, as previously described for FAM208A disruption11. These results demonstrate that the HUSH complex represses primate immunodeficiency virus transcription, and that, to counteract this restriction, viral Vpx or Vpr proteins degrade the HUSH complex.


Assuntos
Produtos do Gene vpr/metabolismo , Lentivirus de Primatas/metabolismo , Provírus/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Antígenos de Neoplasias , Proteínas de Transporte , Proteínas Culina , Produtos do Gene vpr/genética , Células HEK293 , Infecções por HIV/virologia , HIV-1/genética , Humanos , Lentivirus de Primatas/genética , Proteínas Nucleares , Fosfoproteínas , Proteínas Serina-Treonina Quinases , Proteína 1 com Domínio SAM e Domínio HD/metabolismo , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases , Proteínas Virais Reguladoras e Acessórias/genética , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
16.
Molecules ; 23(8)2018 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-30049955

RESUMO

HIV-1 integrase (IN) inhibitors represent a new class of highly effective anti-AIDS therapeutics. Current FDA-approved IN strand transfer inhibitors (INSTIs) share a common mechanism of action that involves chelation of catalytic divalent metal ions. However, the emergence of IN mutants having reduced sensitivity to these inhibitors underlies efforts to derive agents that antagonize IN function by alternate mechanisms. Integrase along with the 96-residue multifunctional accessory protein, viral protein R (Vpr), are both components of the HIV-1 pre-integration complex (PIC). Coordinated interactions within the PIC are important for viral replication. Herein, we report a 7-mer peptide based on the shortened Vpr (69⁻75) sequence containing a biotin group and a photo-reactive benzoylphenylalanyl residue, and which exhibits low micromolar IN inhibitory potency. Photo-crosslinking experiments have indicated that the peptide directly binds IN. The peptide does not interfere with IN-DNA interactions or induce higher-order, aberrant IN multimerization, suggesting a mode of action for the peptide that is distinct from clinically used INSTIs and developmental allosteric IN inhibitors. This compact Vpr-derived peptide may serve as a valuable pharmacological tool to identify a potential new pharmacologic site.


Assuntos
Produtos do Gene vpr/química , Produtos do Gene vpr/metabolismo , Infecções por HIV/virologia , Inibidores de Integrase de HIV/farmacologia , Integrase de HIV/metabolismo , HIV-1/fisiologia , Peptídeos/farmacologia , Sequência de Aminoácidos , Inibidores de Integrase de HIV/síntese química , Inibidores de Integrase de HIV/química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Peptídeos/síntese química , Peptídeos/química , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica
17.
J Infect Dis ; 218(9): 1447-1452, 2018 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-29878133

RESUMO

A 48-year-old woman was infected with a vpr-defective human immunodeficiency virus (HIV)-1 molecular clone. Seroconversion was markedly delayed, and without treatment she had durably suppressed viremia and normal T-cell levels. Neutralizing antibody and CD8+ T-cell immune responses against HIV-1 were unremarkable. Viral sequences confirmed the source but evolved defective nef, suggesting an unknown mechanistic link to vpr. There were subtle qualitative defects in T and B cells. To our knowledge, this is the only case of human infection with a characterized defective HIV-1 molecular clone, which furthermore recapitulated live-attenuated vaccination in macaque models of HIV-1 vaccine research.


Assuntos
Vacinas contra a AIDS/imunologia , Produtos do Gene vpr/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Vacinas Atenuadas/imunologia , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Clonagem Molecular , Feminino , Humanos , Pessoa de Meia-Idade , Vacinação/métodos
18.
Sci Rep ; 7(1): 13362, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-29042644

RESUMO

HIV patients develop hepatic steatosis. We investigated hepatic steatosis in transgenic mice expressing the HIV-1 accessory protein Vpr (Vpr-Tg) in liver and adipose tissues, and WT mice infused with synthetic Vpr. Vpr-Tg mice developed increased liver triglyceride content and elevated ALT, bilirubin and alkaline phosphatase due to three hepatic defects: 1.6-fold accelerated de novo lipogenesis (DNL), 45% slower fatty acid ß-oxidation, and 40% decreased VLDL-triglyceride export. Accelerated hepatic DNL was due to coactivation by Vpr of liver X receptor-α (LXRα) with increased expression of its lipogenic targets Srebp1c, Chrebp, Lpk, Dgat, Fasn and Scd1, and intranuclear SREBP1c and ChREBP. Vpr enhanced association of LXRα with Lxrα and Srebp1c promoters, increased LXRE-LXRα binding, and broadly altered hepatic expression of LXRα-regulated lipid metabolic genes. Diminished hepatic fatty acid ß-oxidation was associated with decreased mRNA expression of Pparα and its targets Cpt1, Aox, Lcad, Ehhadh, Hsd10 and Acaa2, and blunted VLDL export with decreased expression of Mttp and its product microsomal triglyceride transfer protein. With our previous findings that Vpr circulates in HIV patients (including those with undetectable plasma HIV-1 RNA), co-regulates the glucocorticoid receptor and PPARγ and transduces hepatocytes, these data indicate a potential role for Vpr in HIV-associated fatty liver disease.


Assuntos
Produtos do Gene vpr/metabolismo , Infecções por HIV/complicações , Infecções por HIV/genética , HIV-1/fisiologia , Receptores X do Fígado/genética , Hepatopatia Gordurosa não Alcoólica/etiologia , PPAR alfa/genética , Animais , Modelos Animais de Doenças , Regulação da Expressão Gênica , Infecções por HIV/virologia , Hepatócitos/metabolismo , Metabolismo dos Lipídeos , Testes de Função Hepática , Receptores X do Fígado/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR alfa/metabolismo
19.
J Nat Med ; 71(4): 579-589, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28681118

RESUMO

Human immunodeficiency virus type-1 (HIV-1) is a lentiviral family member that encodes the retroviral Gag, Pol, and Env proteins, along with six additional accessory proteins, Tat, Rev, Vpu, Vif, Nef, and Vpr. The currently approved anti-HIV drugs target the Pol and Env encoded proteins. However, these drugs are only effective in reducing viral replication. Furthermore, the drugs' toxicities and the emergence of drug-resistant strains have become serious worldwide problems. Resistance eventually arises to all of the approved anti-HIV drugs, including the newly approved drugs that target HIV integrase (IN). Drug resistance likely emerges because of spontaneous mutations that occur during viral replication. Therefore, new drugs that effectively block other viral components must be developed to reduce the rate of resistance and suppress viral replication with little or no long-term toxicity. The accessory proteins may expand treatment options. Viral protein R (Vpr) is one of the promising drug targets among the HIV accessory proteins. However, the search for inhibitors continues in anti-HIV drug discovery. In this review, we summarize the naturally occurring compounds discovered from two Myanmar medicinal plants as well as their structure-activity relationships. A total of 49 secondary metabolites were isolated from Kaempferia pulchra rhizomes and Picrasama javanica bark, and the types of compounds were identified as isopimarane diterpenoids and picrasane quassinoids, respectively. Among the isolates, 7 diterpenoids and 15 quassinoids were found to be Vpr inhibitors lacking detectable toxicity, and their potencies varied according to their respective functionalities.


Assuntos
Fármacos Anti-HIV/farmacologia , Produtos do Gene vpr/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Picrasma/química , Extratos Vegetais/farmacologia , Zingiberaceae/química , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/antagonistas & inibidores , Diterpenos/farmacologia , HIV-1/fisiologia , Humanos , Mianmar , Fitoterapia , Plantas Medicinais , Quassinas/farmacologia , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
20.
Bioorg Med Chem Lett ; 26(19): 4620-4624, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27575477

RESUMO

Viral protein R (Vpr) is an accessory protein that plays important roles in the viral pathogenesis of Human Immunodeficiency Virus-1 (HIV-1). An assay for anti-Vpr activity, using TREx-HeLa-Vpr cells, is a promising strategy to discover Vpr inhibitors. The anti-Vpr assay revealed that the CHCl3-soluble extract of Picrasma javanica bark possesses potent anti-Vpr activity. Furthermore, studies of quassinoids (1-15) previously isolated from the extract demonstrated that all of the tested quassinoids exhibit anti-Vpr activity. Among the tested compounds, javanicin I (15) exhibited the most potent anti-Vpr activity ((***)p <0.001) in comparing with that of the positive control, damnacanthal. The structure-activity relationships of the active quassinoids suggested that the presence of a methyl group at C-13 in the 2,12,14-triene-1,11,16-trione-2,12-dimethoxy-18-norpicrasane quassinoids is the important factor for the potent inhibitory effect in TREx-HeLa-Vpr cells.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Produtos do Gene vpr/antagonistas & inibidores , Infecções por HIV/tratamento farmacológico , Picrasma/química , Casca de Planta/química , Quassinas/farmacologia , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Células HeLa , Humanos , Mianmar , Quassinas/química , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...