Analysis of primer sets for the PCR-detection of provinis DNA of bovine leukemia virus and human immunodeficiency virus

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.

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Differential N-Linked Glycosylation of Human Immunodeficiency Virus and Ebola Virus Envelope Glycoproteins Modulates Interactions with DC-SIGN and DC-SIGNR

Journal of Virology ◽

10.1128/jvi.77.2.1337-1346.2003 ◽

2003 ◽

Vol 77 (2) ◽

pp. 1337-1346 ◽

Cited By ~ 175

Author(s):

George Lin ◽

Graham Simmons ◽

Stefan Pöhlmann ◽

Frédéric Baribaud ◽

Houping Ni ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Ebola Virus ◽

Leukemia Virus ◽

Viral Envelope ◽

Virus Envelope ◽

Immunodeficiency Virus ◽

High Mannose ◽

Virus Interactions ◽

Do So

ABSTRACT The C-type lectins DC-SIGN and DC-SIGNR [collectively referred to as DC-SIGN(R)] bind and transmit human immunodeficiency virus (HIV) and simian immunodeficiency virus to T cells via the viral envelope glycoprotein (Env). Other viruses containing heavily glycosylated glycoproteins (GPs) fail to interact with DC-SIGN(R), suggesting some degree of specificity in this interaction. We show here that DC-SIGN(R) selectively interact with HIV Env and Ebola virus GPs containing more high-mannose than complex carbohydrate structures. Modulation of N-glycans on Env or GP through production of viruses in different primary cells or in the presence of the mannosidase I inhibitor deoxymannojirimycin dramatically affected DC-SIGN(R) infectivity enhancement. Further, murine leukemia virus, which typically does not interact efficiently with DC-SIGN(R), could do so when produced in the presence of deoxymannojirimycin. We predict that other viruses containing GPs with a large proportion of high-mannose N-glycans will efficiently interact with DC-SIGN(R), whereas those with solely complex N-glycans will not. Thus, the virus-producing cell type is an important factor in dictating both N-glycan status and virus interactions with DC-SIGN(R), which may impact virus tropism and transmissibility in vivo.

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Replacement of Murine Leukemia Virus Readthrough Mechanism by Human Immunodeficiency Virus Frameshift Allows Synthesis of Viral Proteins and Virus Replication

Journal of Virology ◽

10.1128/jvi.77.5.3345-3350.2003 ◽

2003 ◽

Vol 77 (5) ◽

pp. 3345-3350 ◽

Cited By ~ 6

Author(s):

Marie-Noëlle Brunelle ◽

Léa Brakier-Gingras ◽

Guy Lemay

Keyword(s):

Human Immunodeficiency Virus ◽

Murine Leukemia Virus ◽

Stop Codon ◽

Leukemia Virus ◽

Viral Proteins ◽

Immunodeficiency Virus ◽

Virus Model ◽

Polyprotein Precursor ◽

Leukemia Viruses ◽

Murine Leukemia

ABSTRACT Retroviruses use unusual recoding strategies to synthesize the Gag-Pol polyprotein precursor of viral enzymes. In human immunodeficiency virus, ribosomes translating full-length viral RNA can shift back by 1 nucleotide at a specific site defined by the presence of both a slippery sequence and a downstream stimulatory element made of an extensive secondary structure. This so-called frameshift mechanism could become a target for the development of novel antiviral strategies. A different recoding strategy is used by other retroviruses, such as murine leukemia viruses, to synthesize the Gag-Pol precursor; in this case, a stop codon is suppressed in a readthrough process, again due to the presence of a specific structure adopted by the mRNA. Development of antiframeshift agents will greatly benefit from the availability of a simple animal and virus model. For this purpose, the murine leukemia virus readthrough region was rendered inactive by mutagenesis and the frameshift region of human immunodeficiency virus was inserted to generate a chimeric provirus. This substitution of readthrough by frameshift allows the synthesis of viral proteins, and the chimeric provirus sequence was found to generate infectious viruses. This system could be a most interesting alternative to study ribosomal frameshift in the context of a virus amenable to the use of a simple animal model.

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Truncation of the human immunodeficiency virus type 1 envelope glycoprotein allows efficient pseudotyping of Moloney murine leukemia virus particles and gene transfer into CD4+ cells.

Journal of Virology ◽

10.1128/jvi.71.4.3341-3345.1997 ◽

1997 ◽

Vol 71 (4) ◽

pp. 3341-3345 ◽

Cited By ~ 51

Author(s):

F Mammano ◽

F Salvatori ◽

S Indraccolo ◽

A De Rossi ◽

L Chieco-Bianchi ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Envelope Glycoprotein ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Moloney Murine Leukemia Virus ◽

Cd4 Cells ◽

Virus Particles ◽

Immunodeficiency Virus ◽

Murine Leukemia

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Evidence that Ecotropic Murine Leukemia Virus Contamination in TZM-bl Cells Does Not Affect the Outcome of Neutralizing Antibody Assays with Human Immunodeficiency Virus Type 1

Journal of Virology ◽

10.1128/jvi.00709-09 ◽

2009 ◽

Vol 83 (16) ◽

pp. 8289-8292 ◽

Cited By ~ 169

Author(s):

Emily J. Platt ◽

Miroslawa Bilska ◽

Susan L. Kozak ◽

David Kabat ◽

David C. Montefiori

Keyword(s):

Human Immunodeficiency Virus ◽

Cell Line ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Immunodeficiency Virus ◽

Hiv 1 ◽

Murine Leukemia

ABSTRACT The TZM-bl cell line that is commonly used to assess neutralizing antibodies against human immunodeficiency virus type 1 (HIV-1) was recently reported to be contaminated with an ecotropic murine leukemia virus (MLV) (Y. Takeuchi, M. O. McClure, and M. Pizzato, J. Virol. 82:12585-12588, 2008), raising questions about the validity of results obtained with this cell line. Here we confirm this observation and show that HIV-1 neutralization assays performed with a variety of serologic reagents in a similar cell line that does not harbor MLV yield results that are equivalent to those obtained in TZM-bl cells. We conclude that MLV contamination has no measurable effect on HIV-1 neutralization when TZM-bl cells are used as targets for infection.

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Coding Sequences Upstream of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Domain in Gag-Pol Are Not Essential for Incorporation of the Pr160gag-pol into Virus Particles

Journal of Virology ◽

10.1128/jvi.76.7.3221-3231.2002 ◽

2002 ◽

Vol 76 (7) ◽

pp. 3221-3231 ◽

Cited By ~ 24

Author(s):

Hsu-Chen Chiu ◽

Szu-Yung Yao ◽

Chin-Tien Wang

Keyword(s):

Human Immunodeficiency Virus ◽

Reverse Transcriptase ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Leukemia Virus ◽

Deletion Mutants ◽

Coding Region ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Incorporation of the human immunodeficiency virus type 1 (HIV-1) Gag-Pol into virions is thought to be mediated by the N-terminal Gag domain via interaction with the Gag precursor. However, one recent study has demonstrated that the murine leukemia virus Pol can be incorporated into virions independently of Gag-Pol expression, implying a possible interaction between the Pol and Gag precursor. To test whether the HIV-1 Pol can be incorporated into virions on removal of the N-terminal Gag domain and to define sequences required for the incorporation of Gag-Pol into virions in more detail, a series of HIV Gag-Pol expression plasmids with various extensive deletions in the region upstream of the reverse transcriptase (RT) domain was constructed, and viral incorporation of the Gag-Pol deletion mutants was examined by cotransfecting 293T cells with a plasmid expressing Pr55 gag . Analysis indicated that deletion of the N-terminal two-thirds of the gag coding region did not significantly affect the incorporation of Gag-Pol into virions. In contrast, Gag-Pol proteins with deletions covering the capsid (CA) major homology regions and the adjacent C-terminal CA regions were impaired with respect to assembly into virions. However, Gag-Pol with sequences deleted upstream of the protease, or of the RT domain but retaining 15 N-terminal gag codons, could still be rescued into virions at a level about 20% of the wild-type level. When assayed in a nonmyristylated Gag-Pol context, all of the Gag-Pol deletion mutants were incorporated into virions at a level comparable to their myristylated counterparts, suggesting that the incorporation of the Gag-Pol deletion mutants into virions is independent of the N-terminal myristylation signal.

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