scholarly journals Functional Analysis of Vif Protein Shows Less Restriction of Human Immunodeficiency Virus Type 2 by APOBEC3G

2005 ◽  
Vol 79 (2) ◽  
pp. 823-833 ◽  
Author(s):  
Ana Clara Ribeiro ◽  
Alexandra Maia e Silva ◽  
Mariana Santa-Marta ◽  
Ana Pombo ◽  
José Moniz-Pereira ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Replication ◽  
Productive Infection ◽  
Target Cells ◽  
Viral Infectivity ◽  
Single Cycle ◽  
Conserved Motifs ◽  
Immunodeficiency Virus ◽  
Vif Protein ◽  
Hiv 1

ABSTRACT Viral infectivity factor (Vif) is one of the human immunodeficiency virus (HIV) accessory proteins and is conserved in the primate lentivirus group. This protein is essential for viral replication in vivo and for productive infection of nonpermissive cells, such as peripheral blood mononuclear cells (PBMC). Vif counteracts an antiretroviral cellular factor in nonpermissive cells named CEM15/APOBEC3G. Although HIV type 1 (HIV-1) Vif protein (Vif1) can be functionally replaced by HIV-2 Vif protein (Vif2), its identity is very small. Most of the functional studies have been carried out with Vif1. Characterization of functional domains of Vif2 may elucidate its function, as well as differences between HIV-1 and HIV-2 infectivity. Our aim was to identify the permissivity of different cell lines for HIV-2 vif-minus viruses. By mutagenesis specific conserved motifs of HIV-2 Vif protein were analyzed, as well as in conserved motifs between Vif1 and Vif2 proteins. Vif2 mutants were examined for their stability, expression, and cellular localization in order to characterize essential domains of Vif2 proteins. Viral replication in various target cells (PBMC and H9, A3.01, U38, and Jurkat cells) and infectivity in single cycle assays in the presence of APOBEC3G were also analyzed. Our results of viral replication show that only PBMC have a nonpermissive phenotype in the absence of Vif2. Moreover, the HIV-1 vif-minus nonpermissive cell line H9 does not show a similar phenotype for vif-negative HIV-2. We also report a limited effect of APOBEC3G in a single-cycle infectivity assay, where only conserved domains between HIV-1 and HIV-2 Vif proteins influence viral infectivity. Taken together, these results allow us to speculate that viral inhibition by APOBEC3G is not the sole and most important determinant of antiviral activity against HIV-2.

scholarly journals Alpha-enolase in viral target cells suppresses the human immunodeficiency virus type 1 integration

Retrovirology ◽  
2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Naoki Kishimoto ◽  
Kengo Yamamoto ◽  
Nozomi Iga ◽  
Chie Kirihara ◽  
Towa Abe ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Early Phase ◽  
Viral Integration ◽  
Target Cells ◽  
Viral Infectivity ◽  
Immunodeficiency Virus ◽  
Viral Target ◽  
Hiv 1 ◽  
Viral Producer

Abstract Background A protein exhibiting more than one biochemical function is termed a moonlighting protein. Glycolytic enzymes are typical moonlighting proteins, and these enzymes control the infection of various viruses. Previously, we reported that glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and alpha-enolase (ENO1) are incorporated into human immunodeficiency virus type 1 (HIV-1) particles from viral producer cells and suppress viral reverse transcription independently each other. However, it remains unclear whether these proteins expressed in viral target cells affect the early phase of HIV-1 replication. Results Here we show that the GAPDH expression level in viral target cells does not affect the early phase of HIV-1 replication, but ENO1 has a capacity to suppress viral integration in viral target cells. In contrast to GAPDH, suppression of ENO1 expression by RNA interference in the target cells increased viral infectivity, but had no effect on the expression levels of the HIV-1 receptors CD4, CCR5 and CXCR4 and on the level of HIV-1 entry. Quantitative analysis of HIV-1 reverse transcription products showed that the number of copies of the late products (R/gag) and two-long-terminal-repeat circular forms of viral cDNAs did not change but that of the integrated (Alu-gag) form increased. In contrast, overexpression of ENO1 in viral target cells decreased viral infectivity owing to the low viral integration efficiency. Results of subcellular fractionation experiments suggest that the HIV integration at the nucleus was negatively regulated by ENO1 localized in the nucleus. In addition, the overexpression of ENO1 in both viral producer cells and target cells most markedly suppressed the viral replication. Conclusions These results indicate that ENO1 in the viral target cells prevents HIV-1 integration. Importantly, ENO1, but not GAPDH, has the bifunctional inhibitory activity against HIV-1 replication. The results provide and new insights into the function of ENO1 as a moonlighting protein in HIV-1 infection.

scholarly journals Induction of Rapid and Extensive β-Chemokine Synthesis in Macrophages by Human Immunodeficiency Virus Type 1 and gp120, Independently of Their Coreceptor Phenotype

2001 ◽  
Vol 75 (22) ◽  
pp. 10738-10745 ◽  
Author(s):  
Wonkyu Choe ◽  
David J. Volsky ◽  
Mary Jane Potash
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protein Synthesis ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Productive Infection ◽  
Target Cells ◽  
Chemokine Production ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) interacts with its target cells through CD4 and a coreceptor, generally CCR5 or CXCR4. Macrophages display CD4, CCR5, and CXCR4 that are competent for binding and entry of virus. Virus binding also induces several responses by lymphocytes and macrophages that can be dissociated from productive infection. We investigated the responses of macrophages to exposure to a series of HIV-1 species, R5 species that productively infect and X4 species that do not infect macrophages. We chose to monitor production of several physiologically relevant factors within hours of treatment to resolve virally induced effects that may be unlinked to HIV-1 production. Our novel findings indicate that independently of their coreceptor phenotype and independently of virus replication, exposure to certain R5 and X4 HIV-1 species induced secretion of high levels of macrophage inflammatory protein 1α (MIP-1α), MIP-1β, RANTES, and tumor necrosis factor alpha. However two of the six R5 species tested, despite efficient infection, were unable to induce rapid chemokine production. The acute effects of virus on macrophages could be mimicked by exposure to purified R5 or the X4 HIV-1 envelope glycoprotein gp120. Depletion of intracellular Ca2+ or inhibition of protein synthesis blocked the chemokine induction, implicating Ca2+-mediated signal transduction and new protein synthesis in the response. The group of viruses able to induce this chemokine response was not consistent with coreceptor usage. We conclude that human macrophages respond rapidly to R5 and X4 envelope binding by production of high levels of physiologically active proteins that are implicated in HIV-1 pathogenesis.

scholarly journals Predominant Mode of Human Immunodeficiency Virus Transfer between T Cells Is Mediated by Sustained Env-Dependent Neutralization-Resistant Virological Synapses

2007 ◽  
Vol 81 (22) ◽  
pp. 12582-12595 ◽  
Author(s):  
Ping Chen ◽  
Wolfgang Hübner ◽  
Matthew A. Spinelli ◽  
Benjamin K. Chen
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Productive Infection ◽  
Target Cells ◽  
Free Virus ◽  
Virus Transfer ◽  
Immunodeficiency Virus ◽  
Virological Synapses ◽  
Viral Transfer ◽  
Hiv 1

ABSTRACT Cell-free human immunodeficiency virus type 1 (HIV-1) can initiate infections, but contact between infected and uninfected T cells can enhance viral spread through intercellular structures called virological synapses (VS). The relative contribution of VS to cell-free viral transfer has not been carefully measured. Using an ultrasensitive, fluorescent virus transfer assay, we estimate that when VS between HIV-expressing Jurkat T cells and primary CD4+ T cells are formed, cell-associated transfer of virus is 18,000-fold more efficient than uptake of cell-free virus. Furthermore, in contrast to cell-free virus uptake, the VS deposits virus rapidly into focal, trypsin-resistant compartments in target T cells. This massive virus internalization requires Env-CD4 receptor interactions but is resistant to inhibition by patient-derived neutralizing antisera that inhibit homologous cell-free virus. Deleting the Env cytoplasmic tail does not abrogate VS-mediated transfer, but it renders the VS sensitive to neutralizing antibodies, suggesting that the tail limits exposure of VS-neutralizing epitopes on the surface of infected cells. Dynamic live imaging of the VS reveals that HIV-expressing cells are polarized and make sustained, Env-dependent contacts with target cells through uropod-like structures. The polarized T-cell morphology, Env-CD4 coordinated adhesion, and viral transfer from HIV-infected to uninfected cells suggest that VS allows HIV-1 to evade antibody neutralization and to disseminate efficiently. Future studies will discern to what extent this massive viral transfer contributes to productive infection or viral dissemination through the migration of virus-carrying T cells.

scholarly journals Alpha-enolase in viral target cells suppresses the human immunodeficiency virus type 1 integration.

2019 ◽  
Author(s):  
Naoki Kishimoto ◽  
Kengo Yamamoto ◽  
Nozomi Iga ◽  
Chie Kirihara ◽  
Nobutoki Takamune ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Early Phase ◽  
Viral Integration ◽  
Target Cells ◽  
Viral Infectivity ◽  
Immunodeficiency Virus ◽  
Viral Target ◽  
Hiv 1 ◽  
Viral Producer

Abstract Background A protein exhibiting more than one biochemical function is termed a moonlighting protein. Glycolytic enzymes are typical moonlighting proteins, and these enzymes control the infection of various viruses. Previously, we reported that glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and alpha-enolase (ENO1) are incorporated into human immunodeficiency virus type 1 (HIV-1) particles from viral producer cells and suppress viral reverse transcription independently each other. However, it remains unclear whether these proteins expressed in viral target cells affect the early phase of HIV-1 replication. Results Here we show that the GAPDH expression level in viral target cells does not affect the early phase of HIV-1 replication, but ENO1 has a capacity to suppress viral integration in viral target cells. In contrast to GAPDH, suppression of ENO1 expression by RNA interference in the target cells increased viral infectivity, but had no effect on the expression levels of the HIV-1 receptors CD4, CCR5 and CXCR4 and on the level of HIV-1 entry. Quantitative analysis of HIV-1 reverse transcription products showed that the number of copies of the late products (R/gag) and two-long-terminal-repeat circular forms of viral cDNAs did not change but that of the integrated (Alu-gag) form increased. In contrast, overexpression of ENO1 in viral target cells decreased viral infectivity owing to the low viral integration efficiency. Results of subcellular fractionation experiments suggest that the HIV integration at the nucleus was negatively regulated by ENO1 localized in the nucleus. In addition, the overexpression of ENO1 in both viral producer cells and target cells most markedly suppressed the viral replication. Conclusions These results indicate that ENO1 in the viral target cells prevents HIV-1 integration. Importantly, ENO1, but not GAPDH, has the bifunctional inhibitory activity against HIV-1 replication. The results provide and new insights into the function of ENO1 as a moonlighting protein in HIV-1 infection.

scholarly journals Fcγ Receptor-Mediated Suppression of Human Immunodeficiency Virus Type 1 Replication in Primary Human Macrophages

2003 ◽  
Vol 77 (7) ◽  
pp. 4081-4094 ◽  
Author(s):  
Danielle Perez-Bercoff ◽  
Annie David ◽  
Hugues Sudry ◽  
Françoise Barré-Sinoussi ◽  
Gianfranco Pancino
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Replication ◽  
Single Cycle ◽  
Immunodeficiency Virus ◽  
Pcr Products ◽  
Monocytes And Macrophages ◽  
Vesicular Stomatitis ◽  
Hiv Type 1 ◽  
Hiv 1

ABSTRACT Permissiveness of monocytes and macrophages to human immunodeficiency virus (HIV) infection is modulated by various stimuli. In this study we demonstrate that stimulation of primary monocytes and monocyte-derived macrophages (MDM) through the receptors for the Fc portion of immunoglobulin G (IgG) (FcγR) inhibits HIV type 1 (HIV-1) replication. Viral p24 production was decreased by 1.5 to 3 log units in MDM infected with both R5 and X4 HIV-1 strains upon stimulation by immobilized IgG but not upon stimulation by soluble IgG or by F(ab′)2 IgG fragments. Although MDM activation by immobilized IgG induced high levels of macrophage-derived chemokine secretion as well as a sustained down-regulation of CD4 and a transient decrease in CCR5 expression, these factors did not appear to play a major role in the suppression of HIV-1 replication. Single-cycle infection of FcγR-stimulated MDM with HIV-1 virions pseudotyped with either HIV-1 R5 or vesicular stomatitis virus G envelopes was inhibited, suggesting a postentry restriction of viral replication. PCR analyses of HIV-1 DNA intermediate replication forms suggested that reverse transcription is not affected by stimulation with immobilized human IgG, at least during the first replication cycle. The accumulation of PCR products corresponding to nuclear unintegrated two-long-terminal-repeat circles and the relative decrease of integrated HIV-1 DNA signals suggest an inhibition of proviral integration. Our data, showing that FcγR-mediated activation of MDM is a potent mechanism of HIV-1 suppression, raise the possibility that FcγR cross-linking by immune complexes may contribute to the control of viral replication in macrophages.

scholarly journals Potential Role for CD63 in CCR5-Mediated Human Immunodeficiency Virus Type 1 Infection of Macrophages

2003 ◽  
Vol 77 (6) ◽  
pp. 3624-3633 ◽  
Author(s):  
Jana J. von Lindern ◽  
Daniel Rojo ◽  
Kathie Grovit-Ferbas ◽  
Christine Yeramian ◽  
Cheng Deng ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Productive Infection ◽  
Target Cells ◽  
Macrophage Infection ◽  
Macrophage Cell ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Macrophages and CD4+ lymphocytes are the principal target cells for human immunodeficiency virus type 1 (HIV-1) infection, but the molecular details of infection may differ between these cell types. During studies to identify cellular molecules that could be involved in macrophage infection, we observed inhibition of HIV-1 infection of macrophages by monoclonal antibody (MAb) to the tetraspan transmembrane glycoprotein CD63. Pretreatment of primary macrophages with anti-CD63 MAb, but not MAbs to other macrophage cell surface tetraspanins (CD9, CD81, and CD82), was shown to inhibit infection by several R5 and dualtropic strains, but not by X4 isolates. The block to productive infection was postfusion, as assessed by macrophage cell-cell fusion assays, but was prior to reverse transcription, as determined by quantitative PCR assay for new viral DNA formation. The inhibitory effects of anti-CD63 in primary macrophages could not be explained by changes in the levels of CD4, CCR5, or β-chemokines. Infections of peripheral blood lymphocytes and certain cell lines were unaffected by treatment with anti-CD63, suggesting that the role of CD63 in HIV-1 infection may be specific for macrophages.

scholarly journals Alpha-enolase in viral target cells suppresses the human immunodeficiency virus type 1 integration.

2020 ◽  
Author(s):  
Naoki Kishimoto ◽  
Kengo Yamamoto ◽  
Nozomi Iga ◽  
Chie Kirihara ◽  
Towa Abe ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Early Phase ◽  
Viral Integration ◽  
Target Cells ◽  
Viral Infectivity ◽  
Immunodeficiency Virus ◽  
Viral Target ◽  
Hiv 1 ◽  
Viral Producer

Abstract Background A protein exhibiting more than one biochemical function is termed a moonlighting protein. Glycolytic enzymes are typical moonlighting proteins, and these enzymes control the infection of various viruses. Previously, we reported that glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and alpha-enolase (ENO1) are incorporated into human immunodeficiency virus type 1 (HIV-1) particles from viral producer cells and suppress viral reverse transcription independently each other. However, it remains unclear whether these proteins expressed in viral target cells affect the early phase of HIV-1 replication. Results Here we show that the GAPDH expression level in viral target cells does not affect the early phase of HIV-1 replication, but ENO1 has a capacity to suppress viral integration in viral target cells. In contrast to GAPDH, suppression of ENO1 expression by RNA interference in the target cells increased viral infectivity, but had no effect on the expression levels of the HIV-1 receptors CD4, CCR5 and CXCR4 and on the level of HIV-1 entry. Quantitative analysis of HIV-1 reverse transcription products showed that the number of copies of the late products (R/ gag ) and two-long-terminal-repeat circular forms of viral cDNAs did not change but that of the integrated (Alu- gag ) form increased. In contrast, overexpression of ENO1 in viral target cells decreased viral infectivity owing to the low viral integration efficiency. Results of subcellular fractionation experiments suggest that the HIV integration at the nucleus was negatively regulated by ENO1 localized in the nucleus. In addition, the overexpression of ENO1 in both viral producer cells and target cells most markedly suppressed the viral replication. Conclusions These results indicate that ENO1 in the viral target cells prevents HIV-1 integration. Importantly, ENO1, but not GAPDH, has the bifunctional inhibitory activity against HIV-1 replication. The results provide and new insights into the function of ENO1 as a moonlighting protein in HIV-1 infection.

scholarly journals Alpha-enolase in viral target cells suppresses the human immunodeficiency virus type 1 integration.

2020 ◽  
Author(s):  
Naoki Kishimoto ◽  
Kengo Yamamoto ◽  
Nozomi Iga ◽  
Chie Kirihara ◽  
Towa Abe ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Early Phase ◽  
Viral Integration ◽  
Target Cells ◽  
Viral Infectivity ◽  
Immunodeficiency Virus ◽  
Viral Target ◽  
Hiv 1 ◽  
Viral Producer

Abstract BackgroundA protein exhibiting more than one biochemical function is termed a moonlighting protein. Glycolytic enzymes are typical moonlighting proteins, and these enzymes control the infection of various viruses. Previously, we reported that glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and alpha-enolase (ENO1) are incorporated into human immunodeficiency virus type 1 (HIV-1) particles from viral producer cells and suppress viral reverse transcription independently each other. However, it remains unclear whether these proteins expressed in viral target cells affect the early phase of HIV-1 replication.ResultsHere we show that the GAPDH expression level in viral target cells does not affect the early phase of HIV-1 replication, but ENO1 has a capacity to suppress viral integration in viral target cells. In contrast to GAPDH, suppression of ENO1 expression by RNA interference in the target cells increased viral infectivity, but had no effect on the expression levels of the HIV-1 receptors CD4, CCR5 and CXCR4 and on the level of HIV-1 entry. Quantitative analysis of HIV-1 reverse transcription products showed that the number of copies of the late products (R/ gag ) and two-long-terminal-repeat circular forms of viral cDNAs did not change but that of the integrated (Alu- gag ) form increased. In contrast, overexpression of ENO1 in viral target cells decreased viral infectivity owing to the low viral integration efficiency. Results of subcellular fractionation experiments suggest that the HIV integration at the nucleus was negatively regulated by ENO1 localized in the nucleus. In addition, the overexpression of ENO1 in both viral producer cells and target cells most markedly suppressed the viral replication.ConclusionsThese results indicate that ENO1 in the viral target cells prevents HIV-1 integration. Importantly, ENO1, but not GAPDH, has the bifunctional inhibitory activity against HIV-1 replication. The results provide and new insights into the function of ENO1 as a moonlighting protein in HIV-1 infection.

scholarly journals Highly Productive Infection with Pseudotyped Human Immunodeficiency Virus Type 1 (HIV-1) Indicates No Intracellular Restrictions to HIV-1 Replication in Primary Human Astrocytes

2001 ◽  
Vol 75 (17) ◽  
pp. 7925-7933 ◽  
Author(s):  
Mario Canki ◽  
Janice Ngee Foong Thai ◽  
Wei Chao ◽  
Anuja Ghorpade ◽  
Mary Jane Potash ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Productive Infection ◽  
Human Astrocytes ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Virus Expression ◽  
Hiv 1

ABSTRACT Human astrocytes can be infected with human immunodeficiency virus type 1 (HIV-1) in vitro and in vivo, but, in contrast to T lymphocytes and macrophages, virus expression is inefficient. To investigate the HIV-1 life cycle in human fetal astrocytes, we infected cells with HIV-1 pseudotyped with envelope glycoproteins of either amphotropic murine leukemia virus or vesicular stomatitis virus. Infection by both pseudotypes was productive and long lasting and reached a peak of 68% infected cells and 1.7 μg of viral p24 per ml of culture supernatant 7 days after virus inoculation and then continued with gradually declining levels of virus expression through 7 weeks of follow-up. This contrasted with less than 0.1% HIV-1 antigen-positive cells and 400 pg of extracellular p24 per ml at the peak of astrocyte infection with native HIV-1. Cell viability and growth kinetics were similar in infected and control cells. Northern blot analysis revealed the presence of major HIV-1 RNA species of 9, 4, and 2 kb in astrocytes exposed to pseudotyped (but not wild-type) HIV-1 at 2, 14, and 28 days after infection. Consistent with productive infection, the 9- and 4-kb viral transcripts in astrocytes infected by pseudotyped HIV-1 were as abundant as the 2-kb mRNA during 4 weeks of follow-up, and both structural and regulatory viral proteins were detected in infected cells by immunoblotting or cell staining. The progeny virus released by these cells was infectious. These results indicate that the major barrier to HIV-1 infection of primary astrocytes is at virus entry and that astrocytes have no intrinsic intracellular restriction to efficient HIV-1 replication.

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