scholarly journals Fusogenic segments of bovine leukemia virus and simian immunodeficiency virus are interchangeable and mediate fusion by means of oblique insertion in the lipid bilayer of their target cells.

1992 ◽  
Vol 89 (9) ◽  
pp. 3810-3814 ◽  
Author(s):  
V. Voneche ◽  
D. Portetelle ◽  
R. Kettmann ◽  
L. Willems ◽  
K. Limbach ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Lipid Bilayer ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Target Cells ◽  
Immunodeficiency Virus

scholarly journals Coreceptor-Dependent Inhibition of the Cell Fusion Activity of Simian Immunodeficiency Virus Env Proteins

2000 ◽  
Vol 74 (13) ◽  
pp. 6217-6222 ◽  
Author(s):  
Chinglai Yang ◽  
Qingyuan Yang ◽  
Richard W. Compans
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Hela Cells ◽  
Leukemia Virus ◽  
Inhibitory Effect ◽  
Peptide Sequence ◽  
Target Cells ◽  
Fusion Activity ◽  
Immunodeficiency Virus ◽  
Dependent Inhibition ◽  
Env Protein

ABSTRACT The cytoplasmic tail (R peptide) sequence is able to regulate the fusion activity of the murine leukemia virus (MuLV) envelope (Env) protein. We have previously shown that this sequence exerts a profound inhibitory effect on the fusion activity of simian immunodeficiency virus (SIV)-MuLV chimeric Env proteins which contain the extracellular and transmembrane domains of the SIV Env protein. Recent studies have shown that SIV can utilize several alternative cellular coreceptors for its fusion and entry into the cell. We have investigated the fusion activity of SIV and SIV-MuLV chimeric Env proteins using cells that express different coreceptors. HeLa cells were transfected with plasmid constructs that carry the SIV or SIV-MuLV chimeric Env protein genes and were overlaid with either CEMx174 cells or Ghost Gpr15 cells, which express the Gpr15 coreceptor for SIV, or Ghost CCR5 cells, which express CCR5, an alternate coreceptor for SIV. The R-peptide sequence in the SIV-MuLV chimeric proteins was found to inhibit the fusion with CEMx174 cells or Ghost Gpr15 cells. However, a significant level of fusion was still observed when HeLa cells expressing the chimeric Env proteins were cocultivated with Ghost CCR5 cells. These results show that the R-peptide sequence exerts differential effects on the fusion activity of SIV Env proteins using target cells that express alternative coreceptors.

scholarly journals Development of Minimal Lentivirus Vectors Derived from Simian Immunodeficiency Virus (SIVmac251) and Their Use for Gene Transfer into Human Dendritic Cells

2000 ◽  
Vol 74 (18) ◽  
pp. 8307-8315 ◽  
Author(s):  
Philippe-Emmanuel Mangeot ◽  
Didier Nègre ◽  
Bertrand Dubois ◽  
Arend J. Winter ◽  
Philippe Leissner ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Simian Immunodeficiency Virus ◽  
Leukemia Virus ◽  
Pcr Amplification ◽  
Target Cells ◽  
Differentiated Cells ◽  
Human Cd34 ◽  
Immunodeficiency Virus ◽  
Central Polypurine Tract ◽  
New Perspective

ABSTRACT Lentivirus-derived vectors are very promising gene delivery systems since they are able to transduce nonproliferating differentiated cells, while murine leukemia virus-based vectors can only transduce cycling cells. Here we report the construction and characterization of highly efficient minimal vectors derived from simian immunodeficiency virus (SIVmac251). High-fidelity PCR amplification of DNA fragments was used to generate a minimal SIV vector formed from a 5′ cytomegalovirus early promoter, the 5′ viral sequences up to the 5′ end of gagrequired for reverse transcription and packaging, the Rev-responsive element, a gene-expressing cassette, and the 3′ long terminal repeat (LTR). Production of SIV vector particles was achieved by transfecting 293T cells with the vector DNA and helper constructs coding for the viral genes and the vesicular stomatitis virus glycoprotein G envelope. These SIV vectors were found to have transducing titers reaching 107 transducing units/ml on HeLa cells and to deliver a gene without transfer of helper functions to target cells. The central polypurine tract can be included in the minimal vector, resulting in a two- to threefold increase in the transduction titers on dividing or growth-arrested cells. Based on this minimal SIV vector, asin vector was designed by deleting 151 nucleotides in the 3′ LTR U3 region, and this SIV sin vector retained high transduction titers. Furthermore, the minimal SIV vector was efficient at transducing terminally differentiated human CD34+cell-derived or monocyte-derived dendritic cells (DCs). Results show that up to 40% of human primary DCs can be transduced by the SIV vectors. This opens a new perspective in the field of immunotherapy.

Fusion of bovine leukemia virus with target cells monitored by R18 fluorescence and PCR assays.

1997 ◽  
Vol 71 (1) ◽  
pp. 738-740 ◽  
Author(s):  
S Zarkik ◽  
F Defrise-Quertain ◽  
D Portetelle ◽  
A Burny ◽  
J M Ruysschaert
Keyword(s):  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Target Cells ◽  
Pcr Assays

scholarly journals Roles of Target Cells and Virus-Specific Cellular Immunity in Primary Simian Immunodeficiency Virus Infection

2004 ◽  
Vol 78 (9) ◽  
pp. 4866-4875 ◽  
Author(s):  
Roland R. Regoes ◽  
Rustom Antia ◽  
David A. Garber ◽  
Guido Silvestri ◽  
Mark B. Feinberg ◽  
...  
Keyword(s):  
Virus Infection ◽  
Simian Immunodeficiency Virus ◽  
Cellular Immunity ◽  
Target Cell ◽  
Rhesus Macaques ◽  
Target Cells ◽  
Ongoing Debate ◽  
Data Set ◽  
Infection Period ◽  
Immunodeficiency Virus

ABSTRACT There is an ongoing debate on whether acute human immunodeficiency virus infection is controlled by target cell limitation or by virus-specific cellular immunity. To resolve this question, we developed a novel mathematical modeling scheme which allows us to incorporate measurements of virus load, target cells, and virus-specific immunity and applied it to a comprehensive data set generated in an experiment involving rhesus macaques infected with simian immunodeficiency virus. Half of the macaques studied were treated during the primary infection period with reagents which block T-cell costimulation and as a result displayed severely impaired virus-specific immune responses. Our results show that early viral replication in normal infection is controlled to a large extent by virus-specific CD8+ T cells and not by target cell limitation.

scholarly journals Bovine leukemia virus protease: comparison with human T-lymphotropic virus and human immunodeficiency virus proteases

2007 ◽  
Vol 88 (7) ◽  
pp. 2052-2063 ◽  
Author(s):  
Tamás Sperka ◽  
Gabriella Miklóssy ◽  
Yunfeng Tie ◽  
Péter Bagossi ◽  
Gábor Zahuczky ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Animal Model ◽  
Amino Acid ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Model Systems ◽  
T Lymphotropic Virus ◽  
Naturally Occurring ◽  
Immunodeficiency Virus ◽  
Hiv 1

Bovine leukemia virus (BLV) is a valuable model system for understanding human T-lymphotropic virus 1 (HTLV-1); the availability of an infectious BLV clone, together with animal-model systems, will help to explore anti-HTLV-1 strategies. Nevertheless, the specificity and inhibitor sensitivity of the BLV protease (PR) have not been characterized in detail. To facilitate such studies, a molecular model for the enzyme was built. The specificity of the BLV PR was studied with a set of oligopeptides representing naturally occurring cleavage sites in various retroviruses. Unlike HTLV-1 PR, but similar to the human immunodeficiency virus 1 (HIV-1) enzyme, BLV PR was able to hydrolyse the majority of the peptides, mostly at the same position as did their respective host PRs, indicating a broad specificity. When amino acid residues of the BLV PR substrate-binding sites were replaced by equivalent ones of the HIV-1 PR, many substitutions resulted in inactive protein, indicating a great sensitivity to mutations, as observed previously for the HTLV-1 PR. The specificity of the enzyme was studied further by using a series of peptides containing amino acid substitutions in a sequence representing a naturally occurring HTLV-1 PR cleavage site. Also, inhibitors of HIV-1 PR, HTLV-1 PR and other retroviral proteases were tested on the BLV PR. Interestingly, the BLV PR was more susceptible than the HTLV-1 PR to the inhibitors tested. Therefore, despite the specificity differences, in terms of mutation intolerance and inhibitor susceptibility of the PR, BLV and the corresponding animal-model systems may provide good models for testing of PR inhibitors that target HTLV-1.

scholarly journals Intrinsic Susceptibility of Rhesus Macaque Peripheral CD4+ T Cells to Simian Immunodeficiency Virus In Vitro Is Predictive of In Vivo Viral Replication

2000 ◽  
Vol 74 (20) ◽  
pp. 9388-9395 ◽  
Author(s):  
Simoy Goldstein ◽  
Charles R. Brown ◽  
Houman Dehghani ◽  
Jeffrey D. Lifson ◽  
Vanessa M. Hirsch
Keyword(s):  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rank Order ◽  
Rhesus Macaques ◽  
Target Cells ◽  
Plasma Viremia ◽  
Immunodeficiency Virus ◽  
Siv Infection

ABSTRACT Previous studies with simian immunodeficiency virus (SIV) infection of rhesus macaques suggested that the intrinsic susceptibility of peripheral blood mononuclear cells (PBMC) to infection with SIV in vitro was predictive of relative viremia after SIV challenge. The present study was conducted to evaluate this parameter in a well-characterized cohort of six rhesus macaques selected for marked differences in susceptibility to SIV infection in vitro. Rank order relative susceptibility of PBMC to SIVsmE543-3-infection in vitro was maintained over a 1-year period of evaluation. Differential susceptibility of different donors was maintained in CD8+T-cell-depleted PBMC, macrophages, and CD4+ T-cell lines derived by transformation of PBMC with herpesvirus saimiri, suggesting that this phenomenon is an intrinsic property of CD4+target cells. Following intravenous infection of these macaques with SIVsmE543-3, we observed a wide range in plasma viremia which followed the same rank order as the relative susceptibility established by in vitro studies. A significant correlation was observed between plasma viremia at 2 and 8 weeks postinoculation and in vitro susceptibility (P < 0.05). The observation that the two most susceptible macaques were seropositive for simian T-lymphotropic virus type 1 may suggests a role for this viral infection in enhancing susceptibility to SIV infection in vitro and in vivo. In summary, intrinsic susceptibility of CD4+ target cells appears to be an important factor influencing early virus replication patterns in vivo that should be considered in the design and interpretation of vaccine studies using the SIV/macaque model.

Vertical transmission of bovine leukemia virus and bovine immunodeficiency virus in dairy cattle herds

2002 ◽  
Vol 84 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Sothy Meas ◽  
Tatsufumi Usui ◽  
Kazuhiko Ohashi ◽  
Chihiro Sugimoto ◽  
Misao Onuma
Keyword(s):  
Dairy Cattle ◽  
Vertical Transmission ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Bovine Immunodeficiency Virus ◽  
Immunodeficiency Virus ◽  
Cattle Herds
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