The impact of molecular manipulation in residue 114 of human immunodeficiency virus type-1 reverse transcriptase on dNTP substrate binding and viral replication

The alteration of a glutamic acid (E) to a glycine (G) amino acid residue at position 89 (E89G alteration) in the human immunodeficiency virus type 1 reverse transcriptase confers decreased susceptibility to several nucleoside analog inhibitors. Because the nonnucleoside inhibitor-binding pocket is adjacent to the deoxynucleoside triphosphate substrate-binding site, the impact of the E89G reverse transcriptase has decreased susceptibility to TIBO R82150, nevirapine, and to a lesser extent, delavirdine. Human immunodeficiency viruses bearing the same mutation displayed decreased susceptibility to inhibition by these compounds in a cell culture virus replication assay.

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Immunogenicity of Mutations Induced by Nucleoside Reverse Transcriptase Inhibitors for Human Immunodeficiency Virus Type 1-Specific Cytotoxic T Cells

Journal of Virology ◽

10.1128/jvi.74.19.9306-9312.2000 ◽

2000 ◽

Vol 74 (19) ◽

pp. 9306-9312 ◽

Cited By ~ 47

Author(s):

Assia Samri ◽

Gaby Haas ◽

Joerg Duntze ◽

Jean-Marc Bouley ◽

Vincent Calvez ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Reverse Transcriptase ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Mononuclear Cells ◽

Immune Therapy ◽

Immunodeficiency Virus ◽

The Impact ◽

Hiv 1

ABSTRACT The impact of drug resistance mutations induced by nucleoside reverse transcriptase (RT) inhibitors (NRTI) on cytotoxic T-lymphocyte (CTL) recognition of human immunodeficiency virus type 1 strain LAI (HIV-1LAI) RT was addressed in 35 treated or untreated patients. Two HIV-1LAI RT regions encompassing mutation M41L, L74V, M184V, and T215Y/F were recognized in 75 and 83% mutated and in 33 and 42% unmutated samples, respectively. A total of 41 new CTL epitopes overlapping these mutations were predicted. Mutations enhanced HLA-binding scores of 17 epitopes, decreased scores of 5, and had no effect in 19. Four predicted epitopes containing mutations 41, 74, and 184 were tested and recognized by CD8 cells from mutated or unmutated samples, with frequencies up to 270 gamma interferon spot-forming cells per 106 peripheral blood mononuclear cells. Therefore, RT mutations induced by NRTI can increase the immunogenicity of RT for CTL and might allow a better immune control of resistant viruses in vivo, suggesting that specific immune therapy might help prevent these mutations.

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Suppression of Viremia and Evolution of Human Immunodeficiency Virus Type 1 Drug Resistance in a Macaque Model for Antiretroviral Therapy

Journal of Virology ◽

10.1128/jvi.01301-07 ◽

2007 ◽

Vol 81 (22) ◽

pp. 12145-12155 ◽

Cited By ~ 41

Author(s):

Zandrea Ambrose ◽

Sarah Palmer ◽

Valerie F. Boltz ◽

Mary Kearney ◽

Kay Larsen ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Drug Resistance ◽

Antiretroviral Therapy ◽

Reverse Transcriptase ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Immunodeficiency Virus ◽

The Impact ◽

Hiv 1

ABSTRACT Antiretroviral therapy (ART) in human immunodeficiency virus type 1 (HIV-1)-infected patients does not clear the infection and can select for drug resistance over time. Not only is drug-resistant HIV-1 a concern for infected individuals on continual therapy, but it is an emerging problem in resource-limited settings where, in efforts to stem mother-to-child-transmission of HIV-1, transient nonnucleoside reverse transcriptase inhibitor (NNRTI) therapy given during labor can select for NNRTI resistance in both mother and child. Questions of HIV-1 persistence and drug resistance are highly amenable to exploration within animals models, where therapy manipulation is less constrained. We examined a pigtail macaque infection model responsive to anti-HIV-1 therapy to study the development of resistance. Pigtail macaques were infected with a pathogenic simian immunodeficiency virus encoding HIV-1 reverse transcriptase (RT-SHIV) to examine the impact of prior exposure to a NNRTI on subsequent ART comprised of a NNRTI and two nucleoside RT inhibitors. K103N resistance-conferring mutations in RT rapidly accumulated in 2/3 infected animals after NNRTI monotherapy and contributed to virologic failure during ART in 1/3 animals. By contrast, ART effectively suppressed RT-SHIV in 5/6 animals. These data indicate that suboptimal therapy facilitates HIV-1 drug resistance and suggest that this model can be used to investigate persisting viral reservoirs.

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Development of a New Methodology for Screening of Human Immunodeficiency Virus Type 1 Microbicides Based on Real-Time PCR Quantification

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00749-06 ◽

2006 ◽

Vol 51 (2) ◽

pp. 638-644 ◽

Cited By ~ 6

Author(s):

Renato S. Aguiar ◽

Luciana J. Costa ◽

Helena S. Pereira ◽

Rodrigo M. Brindeiro ◽

Amilcar Tanuri

Keyword(s):

Human Immunodeficiency Virus ◽

Reverse Transcriptase ◽

Real Time ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Real Time Pcr ◽

Immunodeficiency Virus ◽

The Impact ◽

Hiv 1

ABSTRACT Potential topical retrovirucides or vaginal microbicides against human immunodeficiency virus type 1 (HIV-1) include nonnucleoside reverse transcriptase inhibitors (NNRTIs). To be successful, such agents have to be highly active against cell-free virions. In the present study, we developed a new real-time PCR-based assay to measure the natural endogenous reverse transcription (NERT) activity directly on intact HIV-1 particles in the presence of reverse transcriptase (RT) inhibitors. We further evaluated the permeability to nevirapine (NVP) and efavirenz (EFV) and their retention within nascent viral particles. We also demonstrated the NVP and EFV inhibitory effects on NERT activity and the impact of resistance mutations measured directly by this new strategy. Furthermore, the results showed a clear correlation between NERT activity and classical infectivity assays. The 50% inhibitory concentrations (IC50s) of NVP and EFV were demonstrated to be up to 100-fold higher for cell-free than for cell-associated virions, suggesting that cell-free virions are less permeable to these drugs. Our results suggest that NVP and EFV penetrate both the envelope and the capsid of HIV-1 particles and readily inactivate cell-free virions. However, the characteristics of these NNRTIs, such as lower permeability and lower retention during washing procedures, in cell-free virions reduce their efficacies as microbicides. Here, we demonstrate the usefulness of the NERT real-time PCR as an assay for screening novel antiretroviral compounds with unique mechanisms of action.

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