Interaction of tRNA-Derivatives and Oligonucleotide Primers with AZT-Resistant Mutants of HIV-1 Reverse Transcriptase

1998 ◽  
Vol 6 (11) ◽  
pp. 2041-2049 ◽  
Author(s):  
Olga D. Zakharova ◽  
Olga A. Suturina ◽  
Olga A. Timofeeva ◽  
Severin O. Gudima ◽  
Vitaly I. Yamkovoi ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Oligonucleotide Primers ◽  
Resistant Mutants ◽  
Hiv 1 ◽  
Trna Derivatives

scholarly journals Efavirenz Therapy in Rhesus Macaques Infected with a Chimera of Simian Immunodeficiency Virus Containing Reverse Transcriptase from Human Immunodeficiency Virus Type 1

2004 ◽  
Vol 48 (9) ◽  
pp. 3483-3490 ◽  
Author(s):  
Michael J. Hofman ◽  
Joanne Higgins ◽  
Timothy B. Matthews ◽  
Niels C. Pedersen ◽  
Chalet Tan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Simian Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Rhesus Macaques ◽  
Immunodeficiency Virus ◽  
Resistant Mutants ◽  
Hiv 1

ABSTRACT The specificity of nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) for the RT of human immunodeficiency virus type 1 (HIV-1) has prevented the use of simian immunodeficiency virus (SIV) in the study of NNRTIs and NNRTI-based highly active antiretroviral therapy. However, a SIV-HIV-1 chimera (RT-SHIV), in which the RT from SIVmac239 was replaced with the RT-encoding region from HIV-1, is susceptible to NNRTIs and is infectious to rhesus macaques. We have evaluated the antiviral activity of efavirenz against RT-SHIV and the emergence of efavirenz-resistant mutants in vitro and in vivo. RT-SHIV was susceptible to efavirenz with a mean effective concentration of 5.9 ± 4.5 nM, and RT-SHIV variants selected with efavirenz in cell culture displayed 600-fold-reduced susceptibility. The efavirenz-resistant mutants of RT-SHIV had mutations in RT similar to those of HIV-1 variants that were selected under similar conditions. Efavirenz monotherapy of RT-SHIV-infected macaques produced a 1.82-log-unit decrease in plasma viral-RNA levels after 1 week. The virus load rebounded within 3 weeks in one treated animal and more slowly in a second animal. Virus isolated from these two animals contained the K103N and Y188C or Y188L mutations. The RT-SHIV-rhesus macaque model may prove useful for studies of antiretroviral drug combinations that include efavirenz.

scholarly journals Chain-Terminating Dinucleoside Tetraphosphates Are Substrates for DNA Polymerization by Human Immunodeficiency Virus Type 1 Reverse Transcriptase with Increased Activity against Thymidine Analogue-Resistant Mutants

2006 ◽  
Vol 50 (11) ◽  
pp. 3607-3614 ◽  
Author(s):  
Peter R. Meyer ◽  
Anthony J. Smith ◽  
Suzanne E. Matsuura ◽  
Walter A. Scott
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Thymidine Analogue ◽  
Immunodeficiency Virus ◽  
Dna Chain ◽  
Resistant Mutants ◽  
Hiv 1

ABSTRACT Nucleoside reverse transcriptase inhibitors are an important class of drugs for treatment of human immunodeficiency virus type 1 (HIV-1) infection. Resistance to these drugs is often the result of mutations that increase the transfer of chain-terminating nucleotides from blocked DNA termini to a nucleoside triphosphate acceptor, resulting in the generation of an unblocked DNA chain and synthesis of a dinucleoside polyphosphate containing the chain-terminating deoxynucleoside triphosphate analogue. We have synthesized and purified several dinucleoside tetraphosphates (ddAp4ddA, ddCp4ddC, ddGp4ddG, ddTp4ddT, Ap4ddG, 2′(3′)-O-(N-methylanthraniloyl)-Ap4ddG, and AppNHppddG) and show that these compounds can serve as substrates for DNA chain elongation and termination resulting in inhibition of DNA synthesis. Thymidine analogue-resistant mutants of reverse transcriptase are up to 120-fold more sensitive to inhibition by these compounds than is wild-type enzyme. Drugs based on the dinucleoside tetraphosphate structure could delay or prevent the emergence of mutants with enhanced primer unblocking activity. In addition, such drugs could suppress the resistance phenotype of mutant HIV-1 that is present in individuals infected with resistant virus.

Slow-, Tight-Binding HIV-1 Reverse Transcriptase Non-Nucleoside Inhibitors Highly Active against Drug-Resistant Mutants

ChemMedChem ◽  
2007 ◽  
Vol 2 (4) ◽  
pp. 445-448 ◽  
Author(s):  
Reynel Cancio ◽  
Antonello Mai ◽  
Dante Rotili ◽  
Marino Artico ◽  
Gianluca Sbardella ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Tight Binding ◽  
Drug Resistant ◽  
Highly Active ◽  
Resistant Mutants ◽  
Nucleoside Inhibitors ◽  
Hiv 1

scholarly journals Reduced Fitness in Cell Culture of HIV-1 with Nonnucleoside Reverse Transcriptase Inhibitor-Resistant Mutations Correlates with Relative Levels of Reverse Transcriptase Content and RNase H Activity in Virions

2010 ◽  
Vol 84 (18) ◽  
pp. 9377-9389 ◽  
Author(s):  
Jiong Wang ◽  
Robert A. Bambara ◽  
Lisa M. Demeter ◽  
Carrie Dykes
Keyword(s):  
Cell Culture ◽  
Reverse Transcriptase ◽  
Substantial Reduction ◽  
Transcriptase Inhibitor ◽  
Rnase H ◽  
Relative Fitness ◽  
Resistant Mutants ◽  
Cell Culture Assay ◽  
Rt Inhibitors ◽  
Hiv 1

ABSTRACT Nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) are important components of multidrug therapy for HIV-1. Understanding the effect of NNRTI-resistant mutants on virus replication and reverse transcriptase (RT) function is valuable for the development of extended-spectrum NNRTIs. We measured the fitness of six NNRTI-resistant mutants, the K103N, V106A, Y181C, G190A, G190S, and P236L viruses, using a flow cytometry-based cell culture assay. K103N and Y181C viruses had fitness similar to that of the wild type while V106A, G190A, G190S, and P236L viruses had reduced fitness. We also determined the biochemical correlates of fitness by measuring the RNase H and polymerization activities of recombinant mutant RTs and virion-associated RTs. The RNase H activities of recombinant and virion-associated RTs correlated with the relative fitness for each mutant. K103N and Y181C mutants had normal RNase H activity; V106A, G190A, and G190S mutants had moderate reductions in activity; and the P236L mutant had substantially reduced activity. With the exception of the P236L mutant, reduced fitness correlates with low virion-associated polymerization efficiency and reduced RT content. Reduced polymerase function in virions derived from low RT content rather than an intrinsic polymerization defect in each RT protein. In conclusion, severe defects in RNase H activity alone, exemplified by the P236L mutant, appear sufficient to cause a substantial reduction in fitness. For the other NNRTI mutants, reductions in RT content decreased both polymerization and RNase H activity in virions. RNase H reduction was compounded by intrinsic RNase H defects in the mutant RTs.

Interaction of HIV-1 Reverse Transcriptase with Modified Oligonucleotide Primers Containing 2 -O- -D-Ribofuranosyladenosine

2004 ◽  
Vol 69 (2) ◽  
pp. 130-136
Author(s):  
A. S. Golubeva ◽  
B. S. Ermolinsky ◽  
E. V. Efimtseva ◽  
V. L. Tunitskaya ◽  
A. van Aerschot ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Oligonucleotide Primers ◽  
Modified Oligonucleotide ◽  
Hiv 1

scholarly journals Impact of Clinical Reverse Transcriptase Sequences on the Replication Capacity of HIV-1 Drug-Resistant Mutants

Virology ◽  
2001 ◽  
Vol 285 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Carrie Dykes ◽  
Kora Fox ◽  
Amanda Lloyd ◽  
Michael Chiulli ◽  
Eugene Morse ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Replication Capacity ◽  
Drug Resistant ◽  
Resistant Mutants ◽  
Hiv 1

scholarly journals Competitive Fitness of Nevirapine-Resistant Human Immunodeficiency Virus Type 1 Mutants

2004 ◽  
Vol 78 (2) ◽  
pp. 603-611 ◽  
Author(s):  
Jennifer A. Collins ◽  
M. Gregory Thompson ◽  
Elijah Paintsil ◽  
Melisa Ricketts ◽  
Joanna Gedzior ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Drug Resistant ◽  
Wild Type ◽  
Competitive Fitness ◽  
Immunodeficiency Virus ◽  
Resistant Mutants ◽  
Nevirapine Resistance ◽  
Hiv 1

ABSTRACT Determining the fitness of drug-resistant human immunodeficiency virus type 1 (HIV-1) strains is necessary for the development of population-based studies of resistance patterns. For this purpose, we have developed a reproducible, systematic assay to determine the competitive fitness of HIV-1 drug-resistant mutants. To demonstrate the applicability of this assay, we tested the fitness of the five most common nevirapine-resistant mutants (103N, 106A, 181C, 188C, and 190A), with mutations in HIV-1 reverse transcriptase (RT), singly and in combination (for a total of 31 variants) in a defined HIV-1 background. For these experiments, the 27 RT variants that produced viable virus were cocultured with wild-type virus without nevirapine. The ratios of the viral species were determined over time by utilization of a quantitative real-time RT-PCR-based assay. These experiments revealed that all of the viable variants were less fit than the wild type and demonstrated that the order of relative fitness of the single mutants tested was as follows: 103N > 181C > 190A > 188C > 106A. This order correlated with the commonality of these mutants as a result of nevirapine monotherapy. These investigations also revealed that, on average, the double mutants were less fit than the single mutants and the triple mutants were less fit than the double mutants. However, the fitness of the single and double mutants was often not predictive of the fitness of the derivative triple mutants, suggesting the presence of complex interactions between the closely aligned residues that confer nevirapine resistance. This complexity was also evident from the observation that all three of the replication-competent quadruple mutants were fitter than most of the triple mutants, and in some cases, even the double mutants. Our data suggest that, in many cases, viral fitness is the determining factor in the evolution of nevirapine-resistant mutants in vivo, that interactions between the residues that confer nevirapine resistance are complex, and that these interactions substantially affect reverse transcriptase structure and/or function.

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