scholarly journals A novel virus capture assay reveals a differential acquisition of host HLA-DR by clinical isolates of human immunodeficiency virus type 1 expanded in primary human cells depending on the nature of producing cells and the donor source

2001 ◽  
Vol 82 (12) ◽  
pp. 2979-2987 ◽  
Author(s):  
Réjean Cantin ◽  
Geneviève Martin ◽  
Michel J. Tremblay
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Host Cells ◽  
Clinical Isolates ◽  
Hla Dr ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Donor Source

Previous findings indicated that HLA-DR is probably one of the most abundant cellular constituents incorporated within the human immunodeficiency virus type 1 (HIV-1) envelope. Given that the life-cycle of HIV-1 has been reported to be modulated by virion-bound host HLA-DR, an improved version of a virus capture technique was developed to assess the degree of HLA-DR incorporation in several clinical isolates of HIV-1 derived from primary human peripheral blood mononuclear cells (PBMCs) and monocyte-derived macrophages (MDM). Analysis of virus stocks purified from PBMCs and MDM indicated that primary isolates of HIV-1 bearing distinct tropism (i.e. T-, macrophage-, and dual-tropic) all incorporate host cell membrane HLA-DR protein. The amount of incorporated HLA-DR varies among the primary HIV-1 isolates tested. Propagation of some clinical HIV-1 isolates in either autologous PBMCs or MDM resulted in differential incorporation of virion-bound cellular HLA-DR depending on the nature of the virus producer cells. Differences in the degree of HLA-DR incorporation were also noticed when macrophage-tropic isolates of HIV-1 were produced in MDM from different donors. Altogether these data show that the efficiency of HLA-DR incorporation into the envelope of primary isolates of HIV-1 is a multifactorial phenomenon since it is affected by the virus isolate itself, the nature of host cells (i.e. PBMCs or MDM) and the donor source.

scholarly journals Comprehensive Analysis of Human Immunodeficiency Virus Type 1-Specific CD4 Responses Reveals Marked Immunodominance of gag and nef and the Presence of Broadly Recognized Peptides

2004 ◽  
Vol 78 (9) ◽  
pp. 4463-4477 ◽  
Author(s):  
Daniel E. Kaufmann ◽  
Paul M. Bailey ◽  
John Sidney ◽  
Bradford Wagner ◽  
Philip J. Norris ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Consensus Sequence ◽  
Acute Infection ◽  
Hla Dr ◽  
Immunodeficiency Virus ◽  
Total Magnitude ◽  
Hiv 1

ABSTRACT Increasing evidence suggests that human immunodeficiency virus type 1 (HIV-1)-specific CD4 T-cell responses contribute to effective immune control of HIV-1 infection. However, the breadths and specificities of these responses have not been defined. We screened fresh CD8-depleted peripheral blood mononuclear cells (PBMC) from 36 subjects at different stages of HIV-1 infection for virus-specific CD4 responses by gamma interferon enzyme-linked immunospot assay, using 410 overlapping peptides spanning all HIV-1 proteins (based on the clade B consensus sequence). HIV-1-specific CD4 responses were identified in 30 of the 36 individuals studied, with the strongest and broadest responses detected in persons treated in acute infection who underwent treatment interruption. In individuals with identified responses, the total number of recognized HIV-1 peptides ranged from 1 to 36 (median, 7) and the total magnitude of responses ranged from 80 to >14,600 (median, 990) spot-forming cells/106 CD8-depleted PBMC. Neither the total magnitude nor the number of responses correlated with viremia. The most frequent and robust responses were directed against epitopes within the Gag and Nef proteins. Peptides targeted by ≥25% of individuals were then tested for binding to a panel of common HLA-DR molecules. All bound broadly to at least four of the eight alleles tested, and two bound to all of the HLA-DR molecules studied. Fine mapping and HLA restriction of the responses against four of these peptides showed a combination of clustering of epitopes and promiscuous presentation of the same epitopes by different HLA class II alleles. These findings have implications for the design of immunotherapeutic strategies and for testing candidate HIV vaccines.

scholarly journals Monitoring Early Fusion Dynamics of Human Immunodeficiency Virus Type 1 at Single-Molecule Resolution

2008 ◽  
Vol 82 (14) ◽  
pp. 7022-7033 ◽  
Author(s):  
Terrence M. Dobrowsky ◽  
Yan Zhou ◽  
Sean X. Sun ◽  
Robert F. Siliciano ◽  
Denis Wirtz
Keyword(s):  
Human Immunodeficiency Virus ◽  
Tensile Strength ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Single Molecule ◽  
Viral Envelope ◽  
Host Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The fusion of human immunodeficiency virus type 1 (HIV-1) to host cells is a dynamic process governed by the interaction between glycoproteins on the viral envelope and the major receptor, CD4, and coreceptor on the surface of the cell. How these receptors organize at the virion-cell interface to promote a fusion-competent site is not well understood. Using single-molecule force spectroscopy, we map the tensile strengths, lifetimes, and energy barriers of individual intermolecular bonds between CCR5-tropic HIV-1 gp120 and its receptors CD4 and CCR5 or CXCR4 as a function of the interaction time with the cell. According to the Bell model, at short times of contact between cell and virion, the gp120-CD4 bond is able to withstand forces up to 35 pN and has an initial lifetime of 0.27 s and an intermolecular length of interaction of 0.34 nm. The initial bond also has an energy barrier of 6.7 kB T (where kB is Boltzmann's constant and T is absolute temperature). However, within 0.3 s, individual gp120-CD4 bonds undergo rapid destabilization accompanied by a shortened lifetime and a lowered tensile strength. This destabilization is significantly enhanced by the coreceptor CCR5, not by CXCR4 or fusion inhibitors, which suggests that it is directly related to a conformational change in the gp120-CD4 bond. These measurements highlight the instability and low tensile strength of gp120-receptor bonds, uncover a synergistic role for CCR5 in the progression of the gp120-CD4 bond, and suggest that the cell-virus adhesion complex is functionally arranged about a long-lived gp120-coreceptor bond.

scholarly journals TMC310911, a Novel Human Immunodeficiency Virus Type 1 Protease Inhibitor, ShowsIn Vitroan Improved Resistance Profile and Higher Genetic Barrier to Resistance Compared with Current Protease Inhibitors

2011 ◽  
Vol 55 (12) ◽  
pp. 5723-5731 ◽  
Author(s):  
Inge Dierynck ◽  
Herwig Van Marck ◽  
Marcia Van Ginderen ◽  
Tim H. M. Jonckers ◽  
Madhavi N. L. Nalam ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Clinical Isolates ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Selection Of

ABSTRACTTMC310911 is a novel human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) structurally closely related to darunavir (DRV) but with improved virological characteristics. TMC310911 has potent activity against wild-type (WT) HIV-1 (median 50% effective concentration [EC50], 14 nM) and a wide spectrum of recombinant HIV-1 clinical isolates, including multiple-PI-resistant strains with decreased susceptibility to currently approved PIs (fold change [FC] in EC50, >10). For a panel of 2,011 recombinant clinical isolates with decreased susceptibility to at least one of the currently approved PIs, the FC in TMC310911 EC50was ≤4 for 82% of isolates and ≤10 for 96% of isolates. The FC in TMC310911 EC50was ≤4 and ≤10 for 72% and 94% of isolates with decreased susceptibility to DRV, respectively.In vitroresistance selection (IVRS) experiments with WT virus and TMC310911 selected for mutations R41G or R41E, but selection of resistant virus required a longer time than IVRS performed with WT virus and DRV. IVRS performed with r13025, a multiple-PI-resistant recombinant clinical isolate, and TMC310911 selected for mutations L10F, I47V, and L90M (FC in TMC310911 EC50= 16). IVRS performed with r13025 in the presence of DRV required less time and resulted in more PI resistance-associated mutations (V32I, I50V, G73S, L76V, and V82I; FC in DRV EC50= 258). The activity against a comprehensive panel of PI-resistant mutants and the limitedin vitroselection of resistant viruses under drug pressure suggest that TMC310911 represents a potential drug candidate for the management of HIV-1 infection for a broad range of patients, including those with multiple PI resistance.

scholarly journals Role of Cholesterol in Human Immunodeficiency Virus Type 1 Envelope Protein-Mediated Fusion with Host Cells

2002 ◽  
Vol 76 (22) ◽  
pp. 11584-11595 ◽  
Author(s):  
Mathias Viard ◽  
Isabella Parolini ◽  
Massimo Sargiacomo ◽  
Katia Fecchi ◽  
Carlo Ramoni ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Membrane Fusion ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Laser Scanning Microscopy ◽  
Host Cells ◽  
Cholesterol Depletion ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT In this study we examined the effects of target membrane cholesterol depletion and cytoskeletal changes on human immunodeficiency virus type 1 (HIV-1) Env-mediated membrane fusion by dye redistribution assays. We found that treatment of peripheral blood lymphocytes (PBL) with methyl-β-cyclodextrin (MβCD) or cytochalasin reduced their susceptibility to membrane fusion with cells expressing HIV-1 Env that utilize CXCR4 or CCR5. However, treatment of human osteosarcoma (HOS) cells expressing high levels of CD4 and coreceptors with these agents did not affect their susceptibility to HIV-1 Env-mediated membrane fusion. Removal of cholesterol inhibited stromal cell-derived factor-1α- and macrophage inflammatory protein 1β-induced chemotaxis of both PBL and HOS cells expressing CD4 and coreceptors. The fusion activity as well as the chemotactic activity of PBL was recovered by adding back cholesterol to these cells. Confocal laser scanning microscopy analysis indicated that treatment of lymphocytes with MβCD reduced the colocalization of CD4 or of CXCR4 with actin presumably in microvilli. These findings indicate that, although cholesterol is not required for HIV-1 Env-mediated membrane fusion per se, its depletion from cells with relatively low coreceptor densities reduces the capacity of HIV-1 Env to engage coreceptor clusters required to trigger fusion. Furthermore, our results suggest that coreceptor clustering may occur in microvilli that are supported by actin polymerization.

scholarly journals Incorporation of HLA-DR into the Envelope of Human Immunodeficiency Virus Type 1 In Vivo: Correlation with Stage of Disease and Presence of Opportunistic Infection

2000 ◽  
Vol 74 (21) ◽  
pp. 10256-10259 ◽  
Author(s):  
Stephen D. Lawn ◽  
Salvatore T. Butera
Keyword(s):  
Human Immunodeficiency Virus ◽  
Virus Replication ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Active Tuberculosis ◽  
Hla Dr ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) bearing HLA-DR in its envelope was detected in plasma from all patients with chronic HIV-1 infection (n = 16) and was present at higher levels in patients with active tuberculosis coinfection (n = 6). Intriguingly, however, HLA-DR was not detectable in HIV-1 from patients during primary viremia (n = 6), suggesting the possibility of virus replication in less-activated cells.

scholarly journals Antiviral properties of palinavir, a potent inhibitor of the human immunodeficiency virus type 1 protease.

1997 ◽  
Vol 41 (5) ◽  
pp. 965-971 ◽  
Author(s):  
D Lamarre ◽  
G Croteau ◽  
E Wardrop ◽  
L Bourgon ◽  
D Thibeault ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Potent Inhibitor ◽  
Clinical Isolates ◽  
Target Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

Palinavir is a potent inhibitor of the human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) proteases. Replication of laboratory strains (HIV-1, HIV-2, and simian immunodeficiency virus) and HIV-1 clinical isolates is inhibited by palinavir with 50% effective concentrations ranging from 0.5 to 30 nM. The average cytotoxic concentration of palinavir (35 microM) in the various target cells indicates a favorable therapeutic index. Potent antiviral activity is retained with increased doses of virus and with clinical isolates resistant to zidovudine (AZT), didanosine (ddI), or nevirapine. Combinations of palinavir with either AZT, ddI, or nevirapine demonstrate synergy or additivity in the inhibition of HIV-1 replication. Palinavir retains anti-HIV-1 activity when administered postinfection until times subsequent to the reverse transcription step. In chronically infected CR-10 cells, palinavir blocks Gag precursor polyprotein processing completely, reducing greater than 99% of infectious particle production. The results indicate that the antiviral activity of palinavir is specific to inhibition of the viral protease and occurs at a late stage in the replicative cycle of HIV-1. On the basis of the potent in vitro activity, low-level cytotoxicity, and other data, palinavir was selected for in-depth preclinical evaluation.

scholarly journals Regulation of Virus Release by the Macrophage-Tropic Human Immunodeficiency Virus Type 1 AD8 Isolate Is Redundant and Can Be Controlled by either Vpu or Env

1999 ◽  
Vol 73 (2) ◽  
pp. 887-896 ◽  
Author(s):  
Ulrich Schubert ◽  
Stephan Bour ◽  
Ronald L. Willey ◽  
Klaus Strebel
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Host Cells ◽  
Initiation Codon ◽  
Virus Release ◽  
Independent Functions ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) Vpu and Env proteins are expressed from a bicistronic mRNA. To address the biological significance of the coordinated expression ofvpu and env, we compared the relative effects on particle release of HIV-1 isolates containing an intactvpu gene or carrying point mutations in its initiation codon or internal deletions, respectively. We found that the primary AD8 isolate, which is unable to express vpu due to a mutation in its translation initiation codon, was able to replicate in primary macrophages and peripheral blood mononuclear cells with efficiency similar to that of an isogenic variant expressing Vpu. Interestingly, AD8 lacking a vpu initiation codon produced higher levels of Env protein than its Vpu-expressing isogenic variant. In contrast, disabling Vpu without removing the vpuinitiation codon did not alter Env expression but significantly reduced virus production. AD8 Env when provided in trans was capable of enhancing release not only of AD8 particles but also of viruses of the T-cell-tropic NL4-3 isolate. We conclude that AD8 Env encodes a Vpu-like activity similar to that previously reported for HIV-2 Env proteins and is thus able to augment virus secretion. When expressed at elevated levels, i.e., following mutation of thevpu initiation codon, AD8 Env was able to compensate for the lack of Vpu and thereby ensure efficient virus release. Thus, the ability to regulate virus release is redundant in AD8 and can be controlled by either Vpu or Env. Since Vpu controls several independent functions, including CD4 degradation, our results suggest that some HIV-1 isolates may have evolved a mechanism to regulate Vpu activity without compromising their ability to efficiently replicate in the host cells.

scholarly journals Highly Potent Inhibition of Human Immunodeficiency Virus Type 1 Replication by TAK-220, an Orally Bioavailable Small-Molecule CCR5 Antagonist

2005 ◽  
Vol 49 (8) ◽  
pp. 3474-3482 ◽  
Author(s):  
Katsunori Takashima ◽  
Hiroshi Miyake ◽  
Naoyuki Kanzaki ◽  
Yoshihiko Tagawa ◽  
Xin Wang ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Mononuclear Cells ◽  
Host Cells ◽  
Peripheral Blood Mononuclear ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT TAK-220 is a member of a novel class of chemokine receptor antagonists and is highly specific to CCR5, as determined by receptor binding and calcium mobilization assays. The compound selectively inhibited coreceptor-mediated entry of human immunodeficiency virus type 1 (HIV-1) into host cells and HIV-1 infection mediated by CCR5. TAK-220 inhibited the replication of six CCR5-using (R5) HIV-1 clinical isolates in peripheral blood mononuclear cells (PBMCs) with a mean 90% effective concentration of 13 nM. The anti-HIV-1 activity of TAK-220 was not affected by addition of high concentrations of human serum. It equally inhibited R5 HIV-1 replication in PBMCs obtained from eight different donors, irrespective of the levels of viral production. Furthermore, the anti-HIV-1 activity of TAK-220 was found to be subtype independent. TAK-220 did not induce CCR5 internalization but blocked the binding of two monoclonal antibodies that recognize the second extracellular loop of CCR5 in CCR5-expressing cells. These results suggest that TAK-220 selectively inhibits R5 HIV-1 replication by interfering with coreceptor-mediated entry of the virus into host cells. At a dose of 5 mg/kg of body weight, TAK-220 showed oral bioavailabilities of 9.5 and 28.9% in rats and monkeys, respectively. Thus, TAK-220 is a promising candidate for the treatment of HIV-1 infection.

T20/DP178, an Ectodomain Peptide of Human Immunodeficiency Virus Type 1 gp41, Is an Activator of Human Phagocyte N-Formyl Peptide Receptor

Blood ◽  
1999 ◽  
Vol 93 (11) ◽  
pp. 3885-3892 ◽  
Author(s):  
Shao Bo Su ◽  
Wang-hua Gong ◽  
Ji-Liang Gao ◽  
Wei-Ping Shen ◽  
Michael C. Grimm ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Host Cells ◽  
Formyl Peptide Receptor ◽  
Peptide Receptor ◽  
Immunodeficiency Virus ◽  
Formyl Peptide ◽  
Hiv 1

Human immunodeficiency virus type 1 (HIV-1) envelope protein gp41 mediates viral fusion with human host cells. The peptide segment T20/DP178, located in the C-terminus of the ectodomain of gp41, interacts with the N-terminal leucine zipper-like domain on gp41 to establish the fusogenic conformation of the virus. Synthetic T20/DP178 peptide is highly efficacious in inhibiting HIV-1 infection in vitro by disrupting the transformation of fusogenic status of viral gp41; thus, it has been proposed for clinical trial. We report that synthetic T20/DP178 is a chemoattractant and activator of human peripheral blood phagocytes but not of T lymphocytes. We further demonstrate that T20/DP178 specifically activates a seven-transmembrane, G-protein–coupled phagocyte receptor for N-formylated chemotactic peptides, formyl peptide receptor (FPR). Moreover, synthetic T20/DP178 analogs lacking N-terminal amino acids acted as FPR antagonists. Our results suggest that gp41 peptides regulate phagocyte function via FPR and identify a novel mechanism by which HIV-1 may modulate innate immunity.

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