GB Virus Type C Envelope Protein E2 Elicits Antibodies That React with a Cellular Antigen on HIV-1 Particles and Neutralize Diverse HIV-1 Isolates

ABSTRACT Novel viral vectors that are able to induce both strong and long-lasting immune responses may be required as effective vaccines for human immunodeficiency virus type 1 (HIV-1) infection. Our previous experiments with a replication-competent vaccine strain-based rabies virus (RV) expressing HIV-1 envelope protein from a laboratory-adapted HIV-1 strain (NL4–3) and a primary HIV-1 isolate (89.6) showed that RV-based vectors are excellent for B-cell priming. Here we report that cytotoxic T-lymphocyte (CTL) responses against HIV-1 gp160 are induced by recombinant RVs. Our results indicated that a single inoculation of mice with an RV expressing HIV-1 gp160 induced a solid and long-lasting memory CTL response specific for HIV-1 envelope protein. Moreover, CTLs from immunized mice were not restricted to the homologous HIV-1 envelope protein and were able to cross-kill target cells expressing HIV-1 gp160 from heterologous HIV-1 strains. These studies further suggest promise for RV-based vectors to elicit a persistent immune response against HIV-1 and their potential utility as efficacious anti-HIV-1 vaccines.

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GB Virus Type C E2 Protein Inhibits Human Immunodeficiency Virus Type 1 Assembly Through Interference With HIV-1 Gag Plasma Membrane Targeting

The Journal of Infectious Diseases ◽

10.1093/infdis/jit001 ◽

2013 ◽

Vol 207 (7) ◽

pp. 1171-1180 ◽

Cited By ~ 9

Author(s):

Christine L. Timmons ◽

Qiujia Shao ◽

Chenliang Wang ◽

Ling Liu ◽

Huanliang Liu ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Plasma Membrane ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Membrane Targeting ◽

E2 Protein ◽

Immunodeficiency Virus ◽

Type C ◽

Hiv 1

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An 85-aa segment of the GB virus type C NS5A phosphoprotein inhibits HIV-1 replication in CD4+ Jurkat T cells

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0604728103 ◽

2006 ◽

Vol 103 (42) ◽

pp. 15570-15575 ◽

Cited By ~ 50

Author(s):

J. Xiang ◽

J. H. McLinden ◽

Q. Chang ◽

T. M. Kaufman ◽

J. T. Stapleton

Keyword(s):

T Cells ◽

Virus Type ◽

Jurkat T Cells ◽

Type C ◽

Hiv 1

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GB virus type C infection modulates T-cell activation independently of HIV-1 viral load

AIDS ◽

10.1097/qad.0b013e32832d7a11 ◽

2009 ◽

Vol 23 (17) ◽

pp. 2277-2287 ◽

Cited By ~ 44

Author(s):

Maria Teresa Maidana-Giret ◽

Tânia M Silva ◽

Mariana M Sauer ◽

Helena Tomiyama ◽

José Eduardo Levi ◽

...

Keyword(s):

Viral Load ◽

T Cell ◽

Virus Type ◽

T Cell Activation ◽

Cell Activation ◽

Type C ◽

Hiv 1

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A Mutation in the Human Immunodeficiency Virus Type 1 Gag Protein Destabilizes the Interaction of the Envelope Protein Subunits gp120 and gp41

Journal of Virology ◽

10.1128/jvi.80.5.2405-2417.2006 ◽

2006 ◽

Vol 80 (5) ◽

pp. 2405-2417 ◽

Cited By ~ 52

Author(s):

Melody R. Davis ◽

Jiyang Jiang ◽

Jing Zhou ◽

Eric O. Freed ◽

Christopher Aiken

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Envelope Protein ◽

Cytoplasmic Tail ◽

Target Cells ◽

Gag Protein ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT The Gag protein of human immunodeficiency virus type 1 (HIV-1) associates with the envelope protein complex during virus assembly. The available evidence indicates that this interaction involves recognition of the gp41 cytoplasmic tail (CT) by the matrix protein (MA) region of Pr55Gag. Here we show that substitution of Asp for Leu at position 49 (L49D) in MA results in a specific reduction in particle-associated gp120 without affecting the levels of gp41. Mutant virions were markedly reduced in single-cycle infectivity despite a relatively modest defect in fusion with target cells. Studies with HIV-1 particles containing decreased levels of envelope proteins suggested that the L49D mutation also inhibits a postentry step in infection. Truncation of the gp41 tail, or pseudotyping by vesicular stomatitis virus glycoprotein, restored both the fusion and infectivity of L49D mutant virions to wild-type levels. Truncation of gp41 also resulted in equivalent levels of gp120 on particles with and without the MA mutation and enhanced the replication of the L49D mutant virus in T cells. The impaired fusion and infectivity of L49D mutant particles were also complemented by a single point mutation in the gp41 CT that disrupted the tyrosine-containing endocytic motif. Our results suggest that an altered interaction between the MA domain of Gag and the gp41 cytoplasmic tail leads to dissociation of gp120 from gp41 during HIV-1 particle assembly, thus resulting in impaired fusion and infectivity.

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Envelope Glycoprotein Incorporation, Not Shedding of Surface Envelope Glycoprotein (gp120/SU), Is the Primary Determinant of SU Content of Purified Human Immunodeficiency Virus Type 1 and Simian Immunodeficiency Virus

Journal of Virology ◽

10.1128/jvi.76.11.5315-5325.2002 ◽

2002 ◽

Vol 76 (11) ◽

pp. 5315-5325 ◽

Cited By ~ 204

Author(s):

Elena Chertova ◽

Julian W. Bess, ◽

Bruce J. Crise ◽

Raymond C. Sowder ◽

Terra M. Schaden ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Simian Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Envelope Glycoprotein ◽

Envelope Protein ◽

Immunodeficiency Virus ◽

Surface Envelope ◽

Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) particles typically contain small amounts of the surface envelope protein (SU), and this is widely believed to be due to shedding of SU from mature virions. We purified proteins from HIV-1 and SIV isolates using procedures which allow quantitative measurements of viral protein content and determination of the ratios of gag- and env-encoded proteins in virions. All of the HIV-1 and most of the SIV isolates examined contained low levels of envelope proteins, with Gag:Env ratios of approximately 60:1. Based on an estimate of 1,200 to 2,500 Gag molecules per virion, this corresponds to an average of between 21 and 42 SU molecules, or between 7 and 14 trimers, per particle. In contrast, some SIV isolates contained levels of SU at least 10-fold greater than SU from HIV-1 isolates. Quantification of relative amounts of SU and transmembrane envelope protein (TM) provides a means to assess the impact of SU shedding on virion SU content, since such shedding would be expected to result in a molar excess of TM over SU on virions that had shed SU. With one exception, viruses with sufficient SU and TM to allow quantification were found to have approximately equivalent molar amounts of SU and TM. The quantity of SU associated with virions and the SU:TM ratios were not significantly changed during multiple freeze-thaw cycles or purification through sucrose gradients. Exposure of purified HIV-1 and SIV to temperatures of 55°C or greater for 1 h resulted in loss of most of the SU from the virus but retention of TM. Incubation of purified virus with soluble CD4 at 37°C resulted in no appreciable loss of SU from either SIV or HIV-1. These results indicate that the association of SU and TM on the purified virions studied is quite stable. These findings suggest that incorporation of SU-TM complexes into the viral membrane may be the primary factor determining the quantity of SU associated with SIV and HIV-1 virions, rather than shedding of SU from mature virions.

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Principal neutralizing domain of the human immunodeficiency virus type 1 envelope protein

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.86.17.6768 ◽

1989 ◽

Vol 86 (17) ◽

pp. 6768-6772 ◽

Cited By ~ 360

Author(s):

K Javaherian ◽

A J Langlois ◽

C McDanal ◽

K L Ross ◽

L I Eckler ◽

...

Keyword(s):

Amino Acids ◽

Human Immunodeficiency Virus ◽

Amino Acid ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Envelope Protein ◽

Neutralizing Antibodies ◽

Immunodeficiency Virus ◽

Hiv 1

The principal neutralizing determinant of human immunodeficiency virus type 1 (HIV-1) is located in the external envelope protein, gp120, and has previously been mapped to a 24-amino acid-long sequence (denoted RP135). We show here that deletion of this sequence renders the envelope unable to elicit neutralizing antibodies. In addition, using synthetic peptide fragments of RP135, we have mapped the neutralizing determinant to 8 amino acids and found that a peptide of this size elicits neutralizing antibodies. This sequence contains a central Gly-Pro-Gly that is generally conserved between different HIV-1 isolates and is flanked by amino acids that differ from isolate to isolate. Antibodies elicited by peptides from one isolate do not neutralize two different isolates, and a hybrid peptide, consisting of amino acid sequences from two isolates, elicits neutralizing antibodies to both isolates. By using a mixture of peptides of this domain or a mixture of such hybrid peptides the type-specificity of the neutralizing antibody response to this determinant can perhaps be overcome.

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Functional Human Immunodeficiency Virus Type 1 (HIV-1) Gag-Pol or HIV-1 Gag-Pol and Env Expressed from a Single Rhabdovirus-Based Vaccine Vector Genome

Journal of Virology ◽

10.1128/jvi.77.20.10889-10899.2003 ◽

2003 ◽

Vol 77 (20) ◽

pp. 10889-10899 ◽

Cited By ~ 42

Author(s):

James P. McGettigan ◽

Kristin Naper ◽

Jan Orenstein ◽

Martin Koser ◽

Philip M. McKenna ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Vaccine Strain ◽

Envelope Protein ◽

Transmembrane Domain ◽

Functional Assay ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Recombinant rabies virus (RV) vaccine strain-based vectors have been successfully developed as vaccines against other viral diseases (J. P. McGettigan et al., J. Virol. 75:4430-4434, 2001; McGettigan et al., J. Virol. 75:8724-8732, 2001; C. A. Siler et al., Virology 292:24-34, 2002), and safety concerns have recently been addressed (McGettigan et al., J. Virol. 77:237-244, 2003). However, size limitations of the vectors may restrict their use for development of vaccine applications that require the expression of large and multiple foreign antigens. Here we describe a new RV-based vaccine vehicle expressing 4.4 kb of the human immunodeficiency virus type 1 (HIV-1) Gag-Pol precursor Pr160. Our results indicate that Pr160 is expressed and processed, as demonstrated by immunostaining and Western blotting. Electron microscopy studies showed both immature and mature HIV-1 virus-like particles (VLPs), indicating that the expressed HIV-1 Gag Pr55 precursor was processed properly by the HIV-1 protease. A functional assay also confirmed the cleavage and functional expression of the HIV-1 reverse transcriptase (RT) from the modified RV genome. In the next step, we constructed and recovered a new RV vaccine strain-based vector expressing a chimeric HIV-189.6P RV envelope protein from an additional RV transcription unit located between the RV nucleoprotein (N) and phosphoprotein (P) in addition to HIV-1 Pr160. The 2.2-kb chimeric HIV-1/RV envelope protein is composed of the HIV-1 Env ectodomain (ED) and transmembrane domain (TD) fused to RV glycoprotein (G) cytoplasmic domain (CD), which is required for efficient incorporation of HIV-1 Env into RV particles. Of note, the expression of both HIV-1 Env and HIV-1 Pr160 resulted in an increase in the rhabdoviral genome of >55%. Both rhabdovirus-expressed HIV-1 precursor proteins were functional, as indicated by RT activity and Env-based fusion assays. These findings demonstrate that both multiple and very large foreign genes can be effectively expressed by RV-based vectors. This research opens up the possibility for the further improvement of rhabdovirus-based HIV-1 vaccines and their use to express large foreign proteins, perhaps from multiple human pathogens.

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Deficiency of Niemann-Pick Type C-1 Protein Impairs Release of Human Immunodeficiency Virus Type 1 and Results in Gag Accumulation in Late Endosomal/Lysosomal Compartments

Journal of Virology ◽

10.1128/jvi.00259-09 ◽

2009 ◽

Vol 83 (16) ◽

pp. 7982-7995 ◽

Cited By ~ 45

Author(s):

Yuyang Tang ◽

Ihid Carneiro Leao ◽

Ebony M. Coleman ◽

Robin Shepard Broughton ◽

James E. K. Hildreth

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Cholesterol Trafficking ◽

Immunodeficiency Virus ◽

Type C ◽

Intracellular Cholesterol ◽

Niemann Pick ◽

Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) relies on cholesterol-laden lipid raft membrane microdomains for entry into and egress out of susceptible cells. In the present study, we examine the need for intracellular cholesterol trafficking pathways with respect to HIV-1 biogenesis using Niemann-Pick type C-1 (NPC1)-deficient (NPCD) cells, wherein these pathways are severely compromised, causing massive accumulation of cholesterol in late endosomal/lysosomal (LE/L) compartments. We have found that induction of an NPC disease-like phenotype through treatment of various cell types with the commonly used hydrophobic amine drug U18666A resulted in profound suppression of HIV-1 release. Further, NPCD Epstein-Barr virus-transformed B lymphocytes and fibroblasts from patients with NPC disease infected with a CD4-independent strain of HIV-1 or transfected with an HIV-1 proviral clone, respectively, replicated HIV-1 poorly compared to normal cells. Infection of the NPCD fibroblasts with a vesicular stomatitis virus G-pseudotyped strain of HIV-1 produced similar results, suggesting a postentry block to HIV-1 replication in these cells. Examination of these cells using confocal microscopy showed an accumulation and stabilization of Gag in LE/L compartments. Additionally, normal HIV-1 production could be restored in NPCD cells upon expression of a functional NPC1 protein, and overexpression of NPC1 increased HIV-1 release. Taken together, our findings demonstrate that intact intracellular cholesterol trafficking pathways mediated by NPC1 are needed for efficient HIV-1 production.

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