scholarly journals Involvement of both the V2 and V3 Regions of the CCR5-Tropic Human Immunodeficiency Virus Type 1 Envelope in Reduced Sensitivity to Macrophage Inflammatory Protein 1α

2000 ◽  
Vol 74 (4) ◽  
pp. 1787-1793 ◽  
Author(s):  
Yosuke Maeda ◽  
Mohamed Foda ◽  
Shuzo Matsushita ◽  
Shinji Harada
Keyword(s):  
Human Immunodeficiency Virus ◽  
Chemokine Receptors ◽  
Luciferase Reporter ◽  
Replication Assay ◽  
Inflammatory Protein ◽  
Immunodeficiency Virus ◽  
Macrophage Inflammatory Protein ◽  
Hiv 1

ABSTRACT To determine whether C-C chemokines play an important role in the phenotype switch of human immunodeficiency virus (HIV) from CCR5 to CXCR4 usage during the course of an infection in vivo, macrophage inflammatory protein (MIP)-1α-resistant variants were isolated from CCR5-tropic (R5) HIV-1 in vitro. The selected variants displayed reduced sensitivities to MIP-1α (fourfold) through CCR5-expressing CD4-HeLa/long terminal repeat–β-galactosidase (MAGI/CCR5) cells. The variants were also resistant to other natural ligands for CCR5, namely, MIP-1β (>4-fold) and RANTES (regulated upon activation, normal T-cell expressed and secreted) (6-fold). The env sequence analyses revealed that the variants had amino acid substitutions in V2 (valine 166 to methionine) and V3 (serine 303 to glycine), although the same V3 substitution appeared in virus passaged without MIP-1α. A single-round replication assay using a luciferase reporter HIV-1 strain pseudotyped with mutant envelopes confirmed that mutations in both V2 and V3 were necessary to confer the reduced sensitivity to MIP-1α, MIP-1β, and RANTES. However, the double mutant did not switch its chemokine receptor usage from CCR5 to CXCR4, indicating the altered recognition of CCR5 by this mutant. These results indicated that V2 combined with the V3 region of the CCR5-tropic HIV-1 envelope modulates the sensitivity of HIV-1 to C-C chemokines without altering the ability to use chemokine receptors.

scholarly journals 1592U89, a novel carbocyclic nucleoside analog with potent, selective anti-human immunodeficiency virus activity.

1997 ◽  
Vol 41 (5) ◽  
pp. 1082-1093 ◽  
Author(s):  
S M Daluge ◽  
S S Good ◽  
M B Faletto ◽  
W H Miller ◽  
M H St Clair ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Bioavailability ◽  
Human Peripheral Blood ◽  
Cross Resistance ◽  
Immunodeficiency Virus ◽  
Carbocyclic Nucleoside ◽  
Hiv 1 ◽  
In Cells

1592U89, (-)-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclo pentene-1-methanol, is a carbocyclic nucleoside with a unique biological profile giving potent, selective anti-human immunodeficiency virus (HIV) activity. 1592U89 was selected after evaluation of a wide variety of analogs containing a cyclopentene substitution for the 2'-deoxyriboside of natural deoxynucleosides, optimizing in vitro anti-HIV potency, oral bioavailability, and central nervous system (CNS) penetration. 1592U89 was equivalent in potency to 3'-azido-3'-deoxythymidine (AZT) in human peripheral blood lymphocyte (PBL) cultures against clinical isolates of HIV type 1 (HIV-1) from antiretroviral drug-naive patients (average 50% inhibitory concentration [IC50], 0.26 microM for 1592U89 and 0.23 microM for AZT). 1592U89 showed minimal cross-resistance (approximately twofold) with AZT and other approved HIV reverse transcriptase (RT) inhibitors. 1592U89 was synergistic in combination with AZT, the nonnucleoside RT inhibitor nevirapine, and the protease inhibitor 141W94 in MT4 cells against HIV-1 (IIIB). 1592U89 was anabolized intracellularly to its 5'-monophosphate in CD4+ CEM cells and in PBLs, but the di- and triphosphates of 1592U89 were not detected. The only triphosphate found in cells incubated with 1592U89 was that of the guanine analog (-)-carbovir (CBV). However, the in vivo pharmacokinetic, distribution, and toxicological profiles of 1592U89 were distinct from and improved over those of CBV, probably because CBV itself was not appreciably formed from 1592U89 in cells or animals (<2%). The 5'-triphosphate of CBV was a potent, selective inhibitor of HIV-1 RT, with Ki values for DNA polymerases (alpha, beta, gamma, and epsilon which were 90-, 2,900-, 1,200-, and 1,900-fold greater, respectively, than for RT (Ki, 21 nM). 1592U89 was relatively nontoxic to human bone marrow progenitors erythroid burst-forming unit and granulocyte-macrophage CFU (IC50s, 110 microM) and human leukemic and liver tumor cell lines. 1592U89 had excellent oral bioavailability (105% in the rat) and penetrated the CNS (rat brain and monkey cerebrospinal fluid) as well as AZT. Having demonstrated an excellent preclinical profile, 1592U89 has progressed to clinical evaluation in HIV-infected patients.

scholarly journals Anti-TAR Polyamide Nucleotide Analog Conjugated with a Membrane-Permeating Peptide Inhibits Human Immunodeficiency Virus Type 1 Production

2002 ◽  
Vol 76 (8) ◽  
pp. 3881-3891 ◽  
Author(s):  
Neerja Kaushik ◽  
Amartya Basu ◽  
Paul Palumbo ◽  
Rene L. Myers ◽  
Virendra N. Pandey
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Treatment ◽  
Significant Inhibition ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Nucleotide Analog ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The emergence of drug-resistant variants has posed a significant setback against effective antiviral treatment for human immunodeficiency virus (HIV) infections. The choice of a nonmutable region of the viral genome such as the conserved transactivation response element (TAR element) in the 5′ long terminal repeat (LTR) may potentially be an effective target for drug development. We have earlier demonstrated that a polyamide nucleotide analog (PNA) targeted to the TAR hairpin element, when transfected into cells, can effectively inhibit Tat-mediated transactivation of HIV type 1 (HIV-1) LTR (T. Mayhood et al., Biochemistry 39:11532-11539, 2000). Here we show that this anti-TAR PNA (PNATAR), upon conjugation with a membrane-permeating peptide vector (transportan) retained its affinity for TAR in vitro similar to the unconjugated analog. The conjugate was efficiently internalized into the cells when added to the culture medium. Examination of the functional efficacy of the PNATAR-transportan conjugate in cell culture using luciferase reporter gene constructs resulted in a significant inhibition of Tat-mediated transactivation of HIV-1 LTR. Furthermore, PNATAR-transportan conjugate substantially inhibited HIV-1 production in chronically HIV-1-infected H9 cells. The mechanism of this inhibition appeared to be regulated at the level of transcription. These results demonstrate the efficacy of PNATAR-transportan as a potential anti-HIV agent.

scholarly journals Human Immunodeficiency Virus Type 1 Vif Protein Is an Integral Component of an mRNP Complex of Viral RNA and Could Be Involved in the Viral RNA Folding and Packaging Process

2000 ◽  
Vol 74 (18) ◽  
pp. 8252-8261 ◽  
Author(s):  
Hui Zhang ◽  
Roger J. Pomerantz ◽  
Geethanjali Dornadula ◽  
Yong Sun
Keyword(s):  
Human Immunodeficiency Virus ◽  
Rna Binding ◽  
Viral Rna ◽  
Immunodeficiency Virus ◽  
Mrnp Complex ◽  
Rna Interaction ◽  
Vif Protein ◽  
Hiv 1

ABSTRACT Virion infectivity factor (Vif) is a protein encoded by human immunodeficiency virus types 1 and 2 (HIV-1 and -2) and simian immunodeficiency virus, plus other lentiviruses, and is essential for viral replication either in vivo or in culture for nonpermissive cells such as peripheral blood lymphoid cells, macrophages, and H9 T cells. Defects in the vif gene affect virion morphology and reverse transcription but not the expression of viral components. It has been shown that Vif colocalizes with Gag in cells and Vif binds to the NCp7 domain of Gag in vitro. However, it seems that Vif is not specifically packaged into virions. The molecular mechanism(s) for Vif remains unknown. In this report, we demonstrate that HIV-1 Vif is an RNA-binding protein and specifically binds to HIV-1 genomic RNA in vitro. Further, Vif binds to HIV-1 RNA in the cytoplasm of virus-producing cells to form a 40S mRNP complex. Coimmunoprecipitation and in vivo UV cross-linking assays indicated that Vif directly interact with HIV-1 RNA in the virus-producing cells. Vif-RNA binding could be displaced by Gag-RNA binding, suggesting that Vif protein in the mRNP complex may mediate viral RNA interaction with HIV-1 Gag precursors. Furthermore, we have demonstrated that these Vif mutants that lose the RNA binding activity in vitro do not supportvif-deficient HIV-1 replication in H9 T cells, suggesting that the RNA binding capacity of Vif is important for its function. Further studies regarding Vif-RNA interaction in virus-producing cells will be important for studying the function of Vif in the HIV-1 life cycle.

scholarly journals Separation of Human Immunodeficiency Virus Type 1 Replication from nef-Mediated Pathogenesis in the Human Thymus

2001 ◽  
Vol 75 (8) ◽  
pp. 3916-3924 ◽  
Author(s):  
Karen M. Duus ◽  
Eric D. Miller ◽  
Jonathan A. Smith ◽  
Grigoriy I. Kovalev ◽  
Lishan Su
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
In Vivo Model ◽  
Immunodeficiency Virus ◽  
Pathogenic Activity ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) is frequently attenuated after long-term culture in vitro. The attenuation process probably involves mutations of functions required for replication and pathogenicity in vivo. Analysis of attenuated HIV-1 for replication and pathogenicity in vivo will help to define these functions. In this study, we examined the pathogenicity of an attenuated HIV-1 isolate in a laboratory worker accidentally exposed to a laboratory-adapted HIV-1 isolate. Using heterochimeric SCID-hu Thy/Liv mice as an in vivo model, we previously defined HIV-1 env determinants (HXB/LW) that reverted to replicate in vivo (L. Su, H. Kaneshima, M. L. Bonyhadi, R. Lee, J. Auten, A. Wolf, B. Du, L. Rabin, B. H. Hahn, E. Terwilliger, and J. M. McCune, Virology 227:46–52, 1997). Here we further demonstrate that HIV-1 replication in vivo can be separated from its pathogenic activity, in that the HXB/LW virus replicated to high levels in SCID-hu Thy/Liv mice, with no significant thymocyte depletion. Restoration of the nef gene in the recombinant HXB/LW genome restored its pathogenic activity, with no significant effect on HIV-1 replication in the thymus. Our results suggest that in vitro-attenuated HIV-1 lacks determinants for pathogenicity as well as for replication in vivo. Our data indicate that (i) the replication defect can be recovered in vivo by mutations in the envgene, without an associated pathogenic phenotype, and (ii)nef can function in the HXB/LW clone as a pathogenic factor that does not enhance HIV-1 replication in the thymus. Furthermore, the HXB/LW virus may be used to study mechanisms of HIV-1nef-mediated pathogenesis in vivo.

scholarly journals Increased Neutralization Sensitivity and Reduced Replicative Capacity of Human Immunodeficiency Virus Type 1 after Short-Term In Vivo or In Vitro Passage through Chimpanzees

2000 ◽  
Vol 74 (17) ◽  
pp. 7699-7707 ◽  
Author(s):  
Tim Beaumont ◽  
Silvia Broersen ◽  
Ad van Nuenen ◽  
Han G. Huisman ◽  
Ana-Maria de Roda Husman ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Short Term ◽  
Neutralization Sensitivity ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Development of disease is extremely rare in chimpanzees when inoculated with either T-cell-line-adapted neutralization-sensitive or primary human immunodeficiency virus type 1 (HIV-1), at first excluding a role for HIV-1 neutralization sensitivity in the clinical course of infection. Interestingly, we observed that short-term in vivo and in vitro passage of primary HIV-1 isolates through chimpanzee peripheral blood mononuclear cells (PBMC) resulted in a neutralization-sensitive phenotype. Furthermore, an HIV-1 variant reisolated from a chimpanzee 10 years after experimental infection was still sensitive to neutralization by soluble CD4, the CD4 binding site recognizing antibody IgG1b12 and autologous chimpanzee serum samples, but had become relatively resistant to neutralization by polyclonal human sera and neutralizing monoclonal antibodies. The initial adaptation of HIV-1 to replicate in chimpanzee PBMC seemed to coincide with a selection for viruses with low replicative kinetics. Neither coreceptor usage nor the expression level of CD4, CCR5, or CXCR4 on chimpanzee PBMC compared to human cells could explain the phenotypic changes observed in these chimpanzee-passaged viruses. Our data suggest that the increased neutralization sensitivity of HIV-1 after replication in chimpanzee cells may in part contribute to the long-term asymptomatic HIV-1 infection in experimentally infected chimpanzees.

scholarly journals How Many Human Immunodeficiency Virus Type 1-Infected Target Cells Can a Cytotoxic T-Lymphocyte Kill?

2005 ◽  
Vol 79 (21) ◽  
pp. 13579-13586 ◽  
Author(s):  
W. David Wick ◽  
Otto O. Yang ◽  
Lawrence Corey ◽  
Steven G. Self
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Target Cells ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT The antiviral role of CD8+ cytotoxic T lymphocytes (CTLs) in human immunodeficiency virus type 1 (HIV-1) infection is poorly understood. Specifically, the degree to which CTLs reduce viral replication by killing HIV-1-infected cells in vivo is not known. Here we employ mathematical models of the infection process and CTL action to estimate the rate that CTLs can kill HIV-1-infected cells from in vitro and in vivo data. Our estimates, which are surprisingly consistent considering the disparities between the two experimental systems, demonstrate that on average CTLs can kill from 0.7 to 3 infected target cells per day, with the variability in this figure due to epitope specificity or other factors. These results are compatible with the observed decline in viremia after primary infection being primarily a consequence of CTL activity and have interesting implications for vaccine design.

scholarly journals Comparison of Antiviral Effects of Zidovudine Phosphoramidate and Phosphorodiamidate Derivatives against HIV and ULV in vitro

1992 ◽  
Vol 3 (2) ◽  
pp. 107-112 ◽  
Author(s):  
D. Kinchington ◽  
J. J. Harvey ◽  
T. J. O'Connor ◽  
B. C. N. M. Jones ◽  
K. G. Devine ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Tissue Culture ◽  
Leukaemia Virus ◽  
Antiviral Effects ◽  
Immunodeficiency Virus ◽  
Similar Range ◽  
Mouse Cells ◽  
Hiv 1

A number of zidovudine phosphoramidate and phosphorodiamidate derivatives were prepared, including some previously unreported benzyl esterified amino acyl compounds. These were found to be active in vitro against the human immunodeficiency virus (HIV-1), and were tested subsequently in the S+L-tissue culture assay against urethane leukaemia virus (ULV), a murine leukaemia virus (MuLV). The fifteen compounds tested showed a similar range of activity against the two viruses. No active compounds were missed in the MuLV system which was usually more sensitive to antiviral effects. Five compounds showed some toxicity to the mouse cells only. We are using this system in parallel with HIV assays to identify those derivatives which will be tested subsequently against a murine retrovirus in vivo.

scholarly journals Structure-Based Design and Engineering of a Nontoxic Recombinant Pokeweed Antiviral Protein with Potent Anti-Human Immunodeficiency Virus Activity

2003 ◽  
Vol 47 (3) ◽  
pp. 1052-1061 ◽  
Author(s):  
Fatih M. Uckun ◽  
Francis Rajamohan ◽  
Sharon Pendergrass ◽  
Zahide Ozer ◽  
Barbara Waurzyniak ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Scid Mouse ◽  
Pokeweed Antiviral Protein ◽  
Antiviral Protein ◽  
Immunodeficiency Virus ◽  
Scid Mouse Model ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT A molecular model of pokeweed antiviral protein (PAP)-RNA interactions was used to rationally engineer FLP-102(151AA152) and FLP-105(191AA192) as nontoxic PAPs with potent anti-human immunodeficiency virus (anti-HIV) activities. FLP-102 and FLP-105 have been produced in Escherichia coli and tested both in vitro and in vivo. These proteins depurinate HIV type 1 (HIV-1) RNA much better than rRNA and are more potent anti-HIV agents than native PAP or recombinant wild-type PAP. They are substantially less toxic than native PAP in BALB/c mice and exhibit potent in vivo activities against genotypically and phenotypically nucleoside reverse transcriptase inhibitor-resistant HIV-1 in a surrogate human peripheral blood lymphocyte (Hu-PBL) SCID mouse model of human AIDS. Rationally engineered nontoxic recombinant PAPs such as FLP-102 and FLP-105 may provide the basis for effective salvage therapies for patients harboring highly drug-resistant strains of HIV-1. The documented in vitro potencies of FLP-102 and FLP-105, their in vivo antiretroviral activities in the HIV-infected Hu-PBL SCID mouse model, and their favorable toxicity profiles in BALB/c mice warrant the further development of these promising new biotherapeutic agents.

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