scholarly journals Defective Strand-Displacement DNA Synthesis Due to Accumulation of Thymidine Analogue Resistance Mutations in HIV-2 Reverse Transcriptase

2020 ◽  
Vol 6 (5) ◽  
pp. 1140-1153 ◽  
Author(s):  
Samara Martín-Alonso ◽  
Mar Álvarez ◽  
María Nevot ◽  
Miguel Á. Martínez ◽  
Luis Menéndez-Arias
Keyword(s):  
Reverse Transcriptase ◽  
Dna Synthesis ◽  
Strand Displacement ◽  
Resistance Mutations ◽  
Thymidine Analogue

scholarly journals 4′-C-Methyl-2′-Deoxyadenosine and 4′-C-Ethyl-2′-Deoxyadenosine Inhibit HIV-1 Replication

2011 ◽  
Vol 55 (5) ◽  
pp. 2379-2389 ◽  
Author(s):  
B. Christie Vu ◽  
Paul L. Boyer ◽  
Maqbool A. Siddiqui ◽  
Victor E. Marquez ◽  
Stephen H. Hughes
Keyword(s):  
Reverse Transcriptase ◽  
Dna Synthesis ◽  
Cultured Cells ◽  
Nucleoside Analogs ◽  
Transcriptase Inhibitor ◽  
Resistance Mutations ◽  
Viral Dna ◽  
Infected Cells ◽  
Hiv 1

ABSTRACTIt is important to develop new anti-HIV drugs that are effective against the existing drug-resistant mutants. Because the excision mechanism is an important pathway for resistance to nucleoside analogs, we are preparing analogs that retain a 3′-OH and can be extended after they are incorporated by the viral reverse transcriptase. We show that 4′-C-alkyl-deoxyadenosine (4′-C-alkyl-dA) compounds can be phosphorylated in cultured cells and can inhibit the replication of HIV-1 vectors: 4′-C-methyl- and 4′-C-ethyl-dA show both efficacy and selectivity against HIV-1. The compounds are also effective against viruses that replicate using reverse transcriptases (RTs) that carry nucleoside reverse transcriptase inhibitor resistance mutations, with the exception of the M184V mutant. Analysis of viral DNA synthesis in infected cells showed that viral DNA synthesis is blocked by the incorporation of either 4′-C-methyl- or 4′-C-ethyl-2′-deoxyadenosine.In vitroexperiments with purified HIV-1 RT showed that 4′-C-methyl-2′-dATP can compete with dATP and that incorporation of the analog causes pausing in DNA synthesis. The 4′-C-ethyl compound also competes with dATP and shows a differential ability to block DNA synthesis on RNA and DNA templates. Experiments that measure the ability of the compounds to block DNA synthesis in infected cells suggest that this differential block to DNA synthesis also occurs in infected cells.

scholarly journals Quantification of the Effects on Viral DNA Synthesis of Reverse Transcriptase Mutations Conferring Human Immunodeficiency Virus Type 1 Resistance to Nucleoside Analogues

2005 ◽  
Vol 79 (2) ◽  
pp. 812-822 ◽  
Author(s):  
Francine Bouchonnet ◽  
Elisabeth Dam ◽  
Fabrizio Mammano ◽  
Vaea de Soultrait ◽  
Gaëlle Henneré ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Dna Synthesis ◽  
Nucleoside Analogues ◽  
Resistance Mutations ◽  
Viral Dna ◽  
Immunodeficiency Virus ◽  
The Impact ◽  
Hiv 1 ◽  
M184v Mutation

ABSTRACT Human immunodeficiency virus type I (HIV-1) reverse transcriptase (RT) resistance mutations reduce the susceptibility of the virus to nucleoside analogues but may also impair viral DNA synthesis. To further characterize the effect of nucleoside analogue resistance mutations on the efficiency and kinetics of HIV-1 DNA synthesis and to evaluate the impact of the depletion of deoxynucleoside triphosphates (dNTP) on this process, DNA synthesis was evaluated by allowing DNA synthesis to proceed with natural HIV-1 templates and primers, either within permeabilized viral particles or in newly infected cells, and quantifying the products by real-time PCR. Three recombinant viruses derived from three pNL4-3 molecular clones expressing mutations associated with resistance to zidovudine: a clone expressing RT mutation M184V, a clone expressing mutations M41L plus T215Y (M41L+T215Y), and clinical isolate BV34 (carrying seven resistance mutations). Following infection of P4 cells, the BV34 mutant, but not viruses expressing the M184V mutation or M41L+T215Y, exhibited a defect in DNA synthesis. Importantly, however, for mutants carrying the M184V mutation or M41L+T215Y mutations, a defect could be detected by using target cells in which dATP pools had been reduced by pretreatment with hydroxyurea. Based on these observations, we developed a recombinant-virus assay to assess the effects of hydroxyurea pretreatment on infectivity of viruses carrying plasma-derived RT sequences from patients with nucleoside resistance. Using this assay, we found that many, but not all, viruses carrying RT resistance mutations display an increased sensitivity to hydroxyurea, suggesting that the impact of RT resistance mutations on viral replication may be more profound in cell populations characterized by smaller dNTP pools.

scholarly journals Involvement of Novel Human Immunodeficiency Virus Type 1 Reverse Transcriptase Mutations in the Regulation of Resistance to Nucleoside Inhibitors

2006 ◽  
Vol 80 (14) ◽  
pp. 7186-7198 ◽  
Author(s):  
Valentina Svicher ◽  
Tobias Sing ◽  
Maria Mercedes Santoro ◽  
Federica Forbici ◽  
Fátima Rodríguez-Barrios ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Antiretroviral Drugs ◽  
Resistance Mutations ◽  
Thymidine Analogue ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We characterized 16 additional mutations in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) whose role in drug resistance is still unknown by analyzing 1,906 plasma-derived HIV-1 subtype B pol sequences from 551 drug-naïve patients and 1,355 nucleoside RT inhibitor (NRTI)-treated patients. Twelve mutations positively associated with NRTI treatment strongly correlated both in pairs and in clusters with known NRTI resistance mutations on divergent evolutionary pathways. In particular, T39A, K43E/Q, K122E, E203K, and H208Y clustered with the nucleoside analogue mutation 1 cluster (NAM1; M41L+L210W+T215Y). Their copresence in this cluster was associated with an increase in thymidine analogue resistance. Moreover, treatment failure in the presence of K43E, K122E, or H208Y was significantly associated with higher viremia and lower CD4 cell count. Differently, D218E clustered with the NAM2 pathway (D67N+K70R+K219Q+T215F), and its presence in this cluster determined an increase in zidovudine resistance. In contrast, three mutations (V35I, I50V, and R83K) negatively associated with NRTI treatment showed negative correlations with NRTI resistance mutations and were associated with increased susceptibility to specific NRTIs. In particular, I50V negatively correlated with the lamivudine-selected mutation M184V and was associated with a decrease in M184V/lamivudine resistance, whereas R83K negatively correlated with both NAM1 and NAM2 clusters and was associated with a decrease in thymidine analogue resistance. Finally, the association pattern of the F214L polymorphism revealed its propensity for the NAM2 pathway and its strong negative association with the NAM1 pathway. Our study provides evidence of novel RT mutational patterns that regulate positively and/or negatively NRTI resistance and strongly suggests that other mutations beyond those currently known to confer resistance should be considered for improved prediction of clinical response to antiretroviral drugs.

Molecular basis of the association of H208Y and thymidine analogue resistance mutations M41L, L210W and T215Y in the HIV-1 reverse transcriptase of treated patients

2014 ◽  
Vol 106 ◽  
pp. 42-52 ◽  
Author(s):  
Gilberto Betancor ◽  
María Nevot ◽  
Jesús Mendieta ◽  
Paulino Gómez-Puertas ◽  
Miguel A. Martínez ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Molecular Basis ◽  
Resistance Mutations ◽  
Thymidine Analogue ◽  
Hiv 1

Genetic Diversity and Drug Resistance of HIV-1 CRF55_01B in Guangdong, China

2020 ◽  
Vol 18 (3) ◽  
pp. 210-218
Author(s):  
Guolong Yu ◽  
Yan Li ◽  
Xuhe Huang ◽  
Pingping Zhou ◽  
Jin Yan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Phylogenetic Analyses ◽  
Resistance Mutations ◽  
Protease Inhibition ◽  
Subtype B ◽  
Primary Drug Resistance ◽  
Hiv 1 ◽  
Primary Drug

Background: HIV-1 CRF55_01B was first reported in 2013. At present, no report is available regarding this new clade’s polymorphisms in its functionally critical regions protease and reverse transcriptase. Objective: To identify the diversity difference in protease and reverse transcriptase between CRF55_01B and its parental clades CRF01_AE and subtype B; and to investigate CRF55_01B’s drug resistance mutations associated with the protease inhibition and reverse transcriptase inhibition. Methods: HIV-1 RNA was extracted from plasma derived from a MSM population. The reverse transcription and nested PCR amplification were performed following our in-house PCR procedure. Genotyping and drug resistant-associated mutations and polymorphisms were identified based on polygenetic analyses and the usage of the HIV Drug Resistance Database, respectively. Results: A total of 9.24 % of the identified CRF55_01B sequences bear the primary drug resistance. CRF55_01B contains polymorphisms I13I/V, G16E and E35D that differ from those in CRF01_AE. Among the 11 polymorphisms in the RT region, seven were statistically different from CRF01_AE’s. Another three polymorphisms, R211K (98.3%), F214L (98.3%), and V245A/E (98.3 %.), were identified in the RT region and they all were statistically different with that of the subtype B. The V179E/D mutation, responsible for 100% potential low-level drug resistance, was found in all CRF55_01B sequences. Lastly, the phylogenetic analyses demonstrated 18 distinct clusters that account for 35% of the samples. Conclusions: CRF55_01B’s pol has different genetic diversity comparing to its counterpart in CRF55_01B’s parental clades. CRF55_01B has a high primary drug resistance presence and the V179E/D mutation may confer more vulnerability to drug resistance.

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