scholarly journals Cooperation of Multiple CCR5 Coreceptors Is Required for Infections by Human Immunodeficiency Virus Type 1

2000 ◽  
Vol 74 (15) ◽  
pp. 7005-7015 ◽  
Author(s):  
Shawn E. Kuhmann ◽  
Emily J. Platt ◽  
Susan L. Kozak ◽  
David Kabat
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cell Surface Receptor ◽  
Dependent Manner ◽  
Immunodeficiency Virus ◽  
Infection Pathway ◽  
Hiv 1

ABSTRACT In addition to the primary cell surface receptor CD4, CCR5 or another coreceptor is necessary for infections by human immunodeficiency virus type 1 (HIV-1), yet the mechanisms of coreceptor function and their stoichiometries in the infection pathway remain substantially unknown. To address these issues, we studied the effects of CCR5 concentrations on HIV-1 infections using wild-type CCR5 and two attenuated mutant CCR5s, one with the mutation Y14N at a critical tyrosine sulfation site in the amino terminus and one with the mutation G163R in extracellular loop 2. The Y14N mutation converted a YYT sequence at positions 14 to 16 to an NYT consensus site for N-linked glycosylation, and the mutant protein was shown to be glycosylated at that position. The relationships between HIV-1 infectivity values and CCR5 concentrations took the form of sigmoidal (S-shaped) curves, which were dramatically altered in different ways by these mutations. Both mutations shifted the curves by factors of approximately 30- to 150-fold along the CCR5 concentration axis, consistent with evidence that they reduce affinities of virus for the coreceptor. In addition, the Y14N mutation specifically reduced the maximum efficiencies of infection that could be obtained at saturating CCR5 concentrations. The sigmoidal curves for all R5 HIV-1 isolates were quantitatively consistent with a simple mathematical model, implying that CCR5s reversibly associate with cell surface HIV-1 in a concentration-dependent manner, that approximately four to six CCR5s assemble around the virus to form a complex needed for infection, and that both mutations inhibit assembly of this complex but only the Y14N mutation also significantly reduces its ability to successfully mediate HIV-1 infections. Although several alternative models would be compatible with our data, a common feature of these alternatives is the cooperation of multiple CCR5s in the HIV-1 infection pathway. This cooperativity will need to be considered in future studies to address in detail the mechanism of CCR5-mediated HIV-1 membrane fusion.

scholarly journals Effects of CCR5 and CD4 Cell Surface Concentrations on Infections by Macrophagetropic Isolates of Human Immunodeficiency Virus Type 1

1998 ◽  
Vol 72 (4) ◽  
pp. 2855-2864 ◽  
Author(s):  
Emily J. Platt ◽  
Kathy Wehrly ◽  
Shawn E. Kuhmann ◽  
Bruce Chesebro ◽  
David Kabat
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Immunoperoxidase Staining ◽  
Dependent Manner ◽  
Wide Range ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT It has been proposed that changes in cell surface concentrations of coreceptors may control infections by human immunodeficiency virus type 1 (HIV-1), but the mechanisms of coreceptor function and the concentration dependencies of their activities are unknown. To study these issues and to generate stable clones of adherent cells able to efficiently titer diverse isolates of HIV-1, we generated two panels of HeLa-CD4/CCR5 cells in which individual clones express either large or small quantities of CD4 and distinct amounts of CCR5. The panels were made by transducing parental HeLa-CD4 cells with the retroviral vector SFF-CCR5. Derivative clones expressed a wide range of CCR5 quantities which were between 7.0 × 102 and 1.3 × 105 molecules/cell as measured by binding antibodies specific for CCR5 and the chemokine [125I]MIP1β. CCR5 was mobile in the membranes, as indicated by antibody-induced patching. In cells with a large amount of CD4, an unexpectedly low trace of CCR5 (between 7 × 102 and 2.0 × 103molecules/cell) was sufficient for maximal susceptibility to all tested HIV-1, including primary patient macrophagetropic and T-cell-tropic isolates. Indeed, the titers as indicated by immunoperoxidase staining of infected foci were as high as the tissue culture infectious doses measured in human peripheral blood mononuclear cells. In contrast, cells with a small amount of CD4 required a much larger quantity of CCR5 for maximal infection by macrophagetropic HIV-1 (ca. 1.0 × 104 to 2.0 × 104 molecules/cell). Cells that expressed low and high amounts of CD4 were infected with equal efficiencies when CCR5 concentrations were above threshold levels for maximal infection. Our results suggest that the concentrations of CD4 and CCR5 required for efficient infections by macrophagetropic HIV-1 are interdependent and that the requirements for each are increased when the other component is present in a limiting amount. We conclude that CD4 and CCR5 directly or indirectly interact in a concentration-dependent manner within a pathway that is essential for infection by macrophagetropic HIV-1. In addition, our results suggest that multivalent virus-receptor bonds and diffusion in the membrane contribute to HIV-1 infections.

scholarly journals Deactivation of Human Immunodeficiency Virus Type 1 in Medium by Copper Oxide-Containing Filters

2008 ◽  
Vol 52 (2) ◽  
pp. 518-525 ◽  
Author(s):  
Gadi Borkow ◽  
Humberto H. Lara ◽  
Chandice Y. Covington ◽  
Adeline Nyamathi ◽  
Jeffrey Gabbay
Keyword(s):  
Human Immunodeficiency Virus ◽  
Copper Oxide ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Dependent Manner ◽  
Blood Donations ◽  
Immunodeficiency Virus ◽  
Dose Dependent ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) can be transmitted through breast-feeding and through contaminated blood donations. Copper has potent biocidal properties and has been found to inactivate HIV-1 infectivity. The objective of this study was to determine the capacity of copper-based filters to inactivate HIV-1 in culture media. Medium spiked with high titers of HIV-1 was exposed to copper oxide powder or copper oxide-impregnated fibers or passed through copper-based filters, and the infectious viral titers before and after treatment were determined. Cell-free and cell-associated HIV-1 infectivity was inhibited when exposed to copper oxide in a dose-dependent manner, without cytotoxicity at the active antiviral copper concentrations. Similar dose-dependent inhibition occurred when HIV-1 was exposed to copper-impregnated fibers. Filtration of HIV-1 through filters containing the copper powder or copper-impregnated fibers resulted in viral deactivation of all 12 wild-type or drug-resistant laboratory or clinical, macrophage-tropic and T-cell-tropic, clade A, B, or C, HIV-1 isolates tested. Viral inactivation was not strain specific. Thus, a novel means to inactivate HIV-1 in medium has been developed. This inexpensive methodology may significantly reduce HIV-1 transmission from “mother to child” and/or through blood donations if proven to be effective in breast milk or plasma and safe for use. The successful application of this technology may impact HIV-1 transmission, especially in developing countries where HIV-1 is rampant.

scholarly journals Role of Cell Surface Glycosaminoglycans of Human T Cells in Human Immunodeficiency Virus Type-1 (HIV-1) Infection

1996 ◽  
Vol 40 (11) ◽  
pp. 827-835 ◽  
Author(s):  
Yukako Ohshiro ◽  
Tsutomu Murakami ◽  
Kazuhiro Matsuda ◽  
Kiyoshi Nishioka ◽  
Keiichi Yoshida ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Human T Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

scholarly journals Human Immunodeficiency Virus Type 1 Derived from Cocultures of Immature Dendritic Cells with Autologous T Cells Carries T-Cell-Specific Molecules on Its Surface and Is Highly Infectious

1999 ◽  
Vol 73 (4) ◽  
pp. 3449-3454 ◽  
Author(s):  
Ines Frank ◽  
Laco Kacani ◽  
Heribert Stoiber ◽  
Hella Stössel ◽  
Martin Spruth ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT During the budding process, human immunodeficiency virus type 1 (HIV-1) acquires cell surface molecules; thus, the viral surface of HIV-1 reflects the antigenic pattern of the host cell. To determine the source of HIV-1 released from cocultures of dendritic cells (DC) with T cells, immature DC (imDC), mature DC (mDC), T cells, and their cocultures were infected with different HIV-1 isolates. The macrophage-tropic HIV-1 isolate Ba-L allowed viral replication in both imDC and mDC, whereas the T-cell-line-tropic primary isolate PI21 replicated in mDC only. By a virus capture assay, HIV-1 was shown to carry a T-cell- or DC-specific cell surface pattern after production by T cells or DC, respectively. Upon cocultivation of HIV-1-pulsed DC with T cells, HIV-1 exclusively displayed a typical T-cell pattern. Additionally, functional analysis revealed that HIV-1 released from imDC–T-cell cocultures was more infectious than HIV-1 derived from mDC–T-cell cocultures and from cultures of DC, T cells, or peripheral blood mononuclear cells alone. Therefore, we conclude that the interaction of HIV-1-pulsed imDC with T cells in vivo might generate highly infectious virus which primarily originates from T cells.

scholarly journals O-Linked N-Acetylglucosaminylation of Sp1 Inhibits the Human Immunodeficiency Virus Type 1 Promoter

2009 ◽  
Vol 83 (8) ◽  
pp. 3704-3718 ◽  
Author(s):  
Ramona Jochmann ◽  
Mathias Thurau ◽  
Susan Jung ◽  
Christian Hofmann ◽  
Elisabeth Naschberger ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Transcription Factors ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Immunodeficiency Virus ◽  
Ltr Promoter ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) gene expression and replication are regulated by the promoter/enhancer located in the U3 region of the proviral 5′ long terminal repeat (LTR). The binding of cellular transcription factors to specific regulatory sites in the 5′ LTR is a key event in the replication cycle of HIV-1. Since transcriptional activity is regulated by the posttranslational modification of transcription factors with the monosaccharide O-linked N-acetyl-d-glucosamine (O-GlcNAc), we evaluated whether increased O-GlcNAcylation affects HIV-1 transcription. In the present study we demonstrate that treatment of HIV-1-infected lymphocytes with the O-GlcNAcylation-enhancing agent glucosamine (GlcN) repressed viral transcription in a dose-dependent manner. Overexpression of O-GlcNAc transferase (OGT), the sole known enzyme catalyzing the addition of O-GlcNAc to proteins, specifically inhibited the activity of the HIV-1 LTR promoter in different T-cell lines and in primary CD4+ T lymphocytes. Inhibition of HIV-1 LTR activity in infected T cells was most efficient (>95%) when OGT was recombinantly overexpressed prior to infection. O-GlcNAcylation of the transcription factor Sp1 and the presence of Sp1-binding sites in the LTR were found to be crucial for this inhibitory effect. From this study, we conclude that O-GlcNAcylation of Sp1 inhibits the activity of the HIV-1 LTR promoter. Modulation of Sp1 O-GlcNAcylation may play a role in the regulation of HIV-1 latency and activation and links viral replication to the glucose metabolism of the host cell. Hence, the establishment of a metabolic treatment might supplement the repertoire of antiretroviral therapies against AIDS.

scholarly journals Passive Sexual Transmission of Human Immunodeficiency Virus Type 1 Variants and Adaptation in New Hosts

2006 ◽  
Vol 80 (14) ◽  
pp. 7226-7234 ◽  
Author(s):  
A. J. Frater ◽  
C. T. T. Edwards ◽  
N. McCarthy ◽  
J. Fox ◽  
H. Brown ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Immune Escape ◽  
Hla Class I ◽  
Class I ◽  
Dependent Manner ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) genetic diversity is a major obstacle for the design of a successful vaccine. Certain viral polymorphisms encode human leukocyte antigen (HLA)-associated immune escape, potentially overcoming limited vaccine protection. Although transmission of immune escape variants has been reported, the overall extent to which this phenomenon occurs in populations and the degree to which it contributes to HIV-1 viral evolution are unknown. Selection on the HIV-1 env gene at transmission favors neutralization-sensitive variants, but it is not known to what degree selection acts on the internal HIV-1 proteins to restrict or enhance the transmission of immune escape variants. Studies have suggested that HLA class I may determine susceptibility to HIV-1 infection, but a definitive role for HLA at transmission remains unproven. Comparing populations of acute seroconverters and chronically infected patients, we found no evidence of selection acting to restrict transmission of HIV-1 variants. We found that statistical associations previously reported in chronic infection between viral polymorphisms and HLA class I alleles are not present in acute infection, suggesting that the majority of viral polymorphisms in these patients are the result of transmission rather than de novo adaptation. Using four episodes of HIV-1 transmission in which the donors and recipients were both sampled very close to the time of infection we found that, despite a transmission bottleneck, genetic variants of HIV-1 infection are transmitted in a frequency-dependent manner. As HIV-1 infections are seeded by unique donor-adapted viral variants, each episode is a highly individual antigenic challenge. Host-specific, idiosyncratic HIV-1 antigenic diversity will seriously tax the efficacy of immunization based on consensus sequences.

scholarly journals Relative roles of signals upstream of AAUAAA and promoter proximity in regulation of human immunodeficiency virus type 1 mRNA 3' end formation.

1992 ◽  
Vol 12 (12) ◽  
pp. 5555-5562 ◽  
Author(s):  
J D DeZazzo ◽  
J M Scott ◽  
M J Imperiale
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Dependent Manner ◽  
Immunodeficiency Virus ◽  
A Site ◽  
The Impact ◽  
Hiv 1 ◽  
Rna Levels

At least two mechanisms have been implicated in regulating poly(A) site use in human immunodeficiency virus type 1 (HIV-1): inhibition of basal signals within 500 nucleotides (nt) of the cap site, leading to specific suppression of the 5' poly(A) site, and stimulation of basal signals by long terminal repeat U3 sequences, leading to specific activation of the 3' poly(A) site. We determined the relative contributions of these mechanisms in a HeLa cell transcription/processing reaction and by transient transfection analysis. In vitro, the efficiency of basal signals is equivalent close to (270 nt) and far from (1,080 nt) the promoter and is stimulated at least 30-fold in both positions by upstream U3 sequences. In vivo, U3 sequences also enhance processing at both positions. There are two additional effects when the poly(A) site is close to the cap site: at least a 15-fold reduction in total RNA levels and a 5-fold decrease in relative levels of RNA processed at the HIV-1 site in constructs containing U3. Both effects are overcome by insertion of upstream splicing signals in an orientation-dependent manner. Splicing appears to influence poly(A)+ RNA levels by two distinct mechanisms: stabilizing nuclear transcripts and directly stimulating 3' end formation. It is proposed that upstream elements play major roles in regulating poly(A) site choice and in controlling the subsequent fate of polyadenylated RNA. The impact of these findings on mechanisms of mRNA biogenesis in the HIV-1 provirus is discussed.

scholarly journals Arsenic Counteracts Human Immunodeficiency Virus Type 1 Restriction by Various TRIM5 Orthologues in a Cell Type-Dependent Manner

2006 ◽  
Vol 80 (4) ◽  
pp. 2051-2054 ◽  
Author(s):  
Sarah Sebastian ◽  
Elena Sokolskaja ◽  
Jeremy Luban
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Lines ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Homo Sapiens ◽  
Primate Species ◽  
Dependent Manner ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Arsenic trioxide (As2O3) increased human immunodeficiency virus type 1 (HIV-1) infectivity when particular Homo sapiens and Cercopithecus aethiops cell lines were used as targets. Knockdown of human TRIM5α by RNA interference eliminated the As2O3 effect, demonstrating that the drug acts by modulating the activity of this retroviral restriction factor. In contrast, HIV-1 infectivity in target cell lines from other primate species (Cercopithecus tantalus, Macaca mulatta, and Aotus trivirgatus) was not increased by As2O3, despite the potent TRIM5-dependent HIV-1 restriction activity that these cells exhibit. To determine if As2O3 responsiveness is characteristic of particular TRIM5 orthologues and not others, TRIM5 cDNAs from these five primate species were transduced into cat fibroblasts, which lack endogenous HIV-1 restriction activity and, therefore, responsiveness to As2O3. In this context, the HIV-1 restriction activity conferred by all TRIM5 orthologues was largely eliminated by As2O3. The effect of As2O3 on HIV-1 restriction is thus shared by different TRIM5 orthologues but dependent on factors specific to the cell line in which TRIM5 is expressed.

scholarly journals Effect of Calcium-Modulating Cyclophilin Ligand on Human Immunodeficiency Virus Type 1 Particle Release and Cell Surface Expression of Tetherin

2009 ◽  
Vol 83 (24) ◽  
pp. 13032-13036 ◽  
Author(s):  
Mariana G. Bego ◽  
Mathieu Dubé ◽  
Johanne Mercier ◽  
Éric A. Cohen
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Particle Release ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) accessory protein Vpu enhances virus particle release by counteracting a host factor that retains virions at the surfaces of infected cells. It was recently demonstrated that cellular protein BST-2/CD317/Tetherin restricts HIV-1 release in a Vpu-dependent manner. Calcium-modulating cyclophilin ligand (CAML) was also proposed to be involved in this process. We investigated whether CAML is involved in cell surface expression of Tetherin. Here, we show that CAML overexpression in permissive Cos-7 cells or CAML depletion in restrictive HeLa cells has no effect on HIV-1 release or on Tetherin surface expression, indicating that CAML is not required for Tetherin-mediated restriction of HIV-1 release.

scholarly journals CCR8 on Human Thymocytes Functions as a Human Immunodeficiency Virus Type 1 Coreceptor

2000 ◽  
Vol 74 (15) ◽  
pp. 6946-6952 ◽  
Author(s):  
Shirley Lee ◽  
H. Lee Tiffany ◽  
Lisa King ◽  
Philip M. Murphy ◽  
Hana Golding ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Productive Infection ◽  
Dependent Manner ◽  
Immunodeficiency Virus ◽  
Dose Dependent ◽  
Similar Affinity ◽  
Hiv 1

ABSTRACT To determine whether human immunodeficiency virus type 1 (HIV-1) coreceptors besides CXCR4 and CCR5 are involved in HIV-1 infection of the thymus, we focused on CCR8, a receptor for the chemokine I-309, because of its high expression in the thymus. Similar levels of CCR8 mRNA were detected in immature and mature primary human thymocytes. Consistent with this, [125I]I-309 was shown to bind specifically and with similar affinity to the surface of immature and mature human thymocytes. Fusion of human thymocytes with cells expressing HIV-1 X4 or X4R5 envelope glycoprotein was inhibited by I-309 in a dose-dependent manner. In addition, I-309 partially inhibited productive infection of human thymocytes by X4, R5, and X4R5 HIV-1 strains. Our data provide the first evidence that CCR8 functions as an HIV-1 coreceptor on primary human cells and suggest that CCR8 may contribute to HIV-1-induced thymic pathogenesis.

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