scholarly journals A sensitive real-time PCR based assay to estimate the impact of amino acid substitutions on the competitive replication fitness of human immunodeficiency virus type 1 in cell culture

2013 ◽  
Vol 189 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Yi Liu ◽  
Sarah Holte ◽  
Ushnal Rao ◽  
Jan McClure ◽  
Philip Konopa ◽  
...  
Keyword(s):  
Cell Culture ◽  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Real Time ◽  
Real Time Pcr ◽  
Amino Acid Substitutions ◽  
Immunodeficiency Virus ◽  
Replication Fitness ◽  
The Impact

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

2006 ◽  
Vol 51 (2) ◽  
pp. 638-644 ◽  
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.

scholarly journals Human Immunodeficiency Virus Type 1 Resistance to the Small Molecule Maturation Inhibitor 3-O-(3′,3′-Dimethylsuccinyl)-Betulinic Acid Is Conferred by a Variety of Single Amino Acid Substitutions at the CA-SP1 Cleavage Site in Gag

2006 ◽  
Vol 80 (24) ◽  
pp. 12095-12101 ◽  
Author(s):  
Jing Zhou ◽  
Chin Ho Chen ◽  
Christopher Aiken
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Betulinic Acid ◽  
Cleavage Site ◽  
Amino Acid Substitutions ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The compound 3-O-(3′,3′-dimethylsuccinyl)-betulinic acid (DSB) potently and specifically inhibits human immunodeficiency virus type 1 (HIV-1) replication by delaying the cleavage of the CA-SP1 junction in Gag, leading to impaired maturation of the viral core. In this study, we investigated HIV-1 resistance to DSB by analyzing HIV-1 mutants encoding a variety of individual amino acid substitutions in the CA-SP1 cleavage site. Three of the substitutions were lethal to HIV-1 replication owing to a deleterious effect on particle assembly. The remaining mutants exhibited a range of replication efficiencies; however, each mutant was capable of replicating in the presence of concentrations of DSB that effectively inhibited wild-type HIV-1. Mutations conferring resistance to DSB also led to impaired binding of the compound to immature HIV-1 virions and loss of DSB-mediated inhibition of cleavage of Gag. Surprisingly, two of the DSB-resistant mutants retained an intermediate ability to bind the compound, suggesting that binding of DSB to immature HIV-1 particles may not be sufficient for antiviral activity. Overall, our results indicate that Gag amino acids L363 and A364 are critical for inhibition of HIV-1 replication by DSB and suggest that these residues form key contacts with the drug in the context of the assembling HIV-1 particle. These results have implications for the design of and screening for novel inhibitors of HIV-1 maturation.

S-1153 Inhibits Replication of Known Drug-Resistant Strains of Human Immunodeficiency Virus Type 1

1998 ◽  
Vol 42 (6) ◽  
pp. 1340-1345 ◽  
Author(s):  
Tamio Fujiwara ◽  
Akihiko Sato ◽  
Mohamed El-Farrash ◽  
Shigeru Miki ◽  
Kenji Abe ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Reverse Transcriptase ◽  
Single Amino Acid ◽  
Amino Acid Substitutions ◽  
Reverse Transcriptase Inhibitors ◽  
Human T Cell ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT S-1153 is a new imidazole compound that inhibits human immunodeficiency virus (HIV) type 1 (HIV-1) replication by acting as a nonnucleoside reverse transcriptase inhibitor (NNRTI). This compound inhibits replication of HIV-1 strains that are resistant to nucleoside and nonnucleoside reverse transcriptase inhibitors. S-1153 has a 50% effective concentration in the range of 0.3 to 7 ng/ml for strains with single amino acid substitutions that cause NNRTI resistance, including the Y181C mutant, and also has potent activity against clinical isolates. The emergence of S-1153-resistant variants is slower than that for nevirapine, and S-1153-resistant variants contained at least two amino acid substitutions, including F227L or L234I. S-1153-resistant variants are still sensitive to the nucleoside reverse transcriptase inhibitors zidovudine (AZT) and lamivudine. In a mouse and MT-4 (human T-cell line) in vivo HIV replication model, S-1153 and AZT administered orally showed a marked synergy for the inhibition of HIV-1 replication. S-1153 shows a significant accumulation in lymph nodes, where most HIV-1 infection is thought to occur. S-1153 may be an appropriate candidate for two- to three-drug combination therapy for HIV infection.

scholarly journals In vitro induction of human immunodeficiency virus type 1 variants resistant to 2'-beta-Fluoro-2',3'-dideoxyadenosine.

1997 ◽  
Vol 41 (6) ◽  
pp. 1313-1318 ◽  
Author(s):  
M Tanaka ◽  
R V Srinivas ◽  
T Ueno ◽  
M F Kavlick ◽  
F K Hui ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Amino Acid Substitutions ◽  
Infectious Clones ◽  
Immunodeficiency Virus ◽  
Hiv 1

2'-beta-Fluoro-2',3'-dideoxyadenosine (F-ddA) is an acid-stable purine dideoxynucleoside analog active against a wide spectrum of human immunodeficiency virus type 1 (HIV-1) and HIV-2 strains in vitro. F-ddA is presently undergoing a phase I clinical trial at the National Cancer Institute. We induced HIV-1 variants resistant to F-ddA by exposing wild-type HIV-1 (HIV-1LAI) to increasing concentrations of F-ddA in vitro. After 18 passages, the virus was fourfold less sensitive to F-ddA than HIV-1LAI. Sequence analyses of the passage 18 virus revealed changes in three amino acids in the reverse transcriptase (RT)-encoding region of the pol gene: P to S at codon 119 (P119S; present in 3 of 13 and 28 of 28 molecular clones before and after F-ddA exposure, respectively), V179D (0 of 13 and 9 of 28, respectively), and L214F (9 of 13 and 28 of 28, respectively). Drug sensitivity assays using recombinant infectious clones confirmed that P119S was directly responsible for the reduced sensitivity of HIV-1 to F-ddA. Various infectious clones with single or multiple amino acid substitutions conferring viral resistance against nucleoside RT inhibitors, including HIV-1 variants with multi-dideoxynucleoside resistance, were generally sensitive to F-ddA. The moderate level of resistance of HIV-1 to F-ddA, together with the lack of conferment of significant cross-resistance by the F-ddA-associated amino acid substitutions, warrants further investigation of F-ddA as a potential antiviral agent for use in treatment of HIV-1 infection.

scholarly journals In Vitro Development of Resistance to Human Immunodeficiency Virus Protease Inhibitor GW640385

2006 ◽  
Vol 50 (3) ◽  
pp. 1092-1095 ◽  
Author(s):  
P. J. Yates ◽  
R. Hazen ◽  
M. St. Clair ◽  
L. Boone ◽  
M. Tisdale ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Protease Inhibitor ◽  
Replication Capacity ◽  
Amino Acid Substitutions ◽  
Development Of Resistance ◽  
Immunodeficiency Virus ◽  
Vitro Development

ABSTRACT Development of in vitro resistance to GW640385, a new human immunodeficiency virus type 1 protease inhibitor, was studied. Variants characterized included one with <4-fold resistance and amino acid substitutions Q58E/A71V (protease) and P452K (Gag) and one with >50-fold resistance and amino acid substitutions L10F/G16E/E21K/A28S/M46I/F53L/A71V (protease) and L449F/P453T (Gag). The A28S substitution substantially reduced replication capacity.

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