scholarly journals A Mutation in the 3′ Region of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase (Y318F) Associated with Nonnucleoside Reverse Transcriptase Inhibitor Resistance

2002 ◽  
Vol 76 (13) ◽  
pp. 6836-6840 ◽  
Author(s):  
P. Richard Harrigan ◽  
Mahboob Salim ◽  
David K. Stammers ◽  
Brian Wynhoven ◽  
Zabrina L. Brumme ◽  
...  

ABSTRACT The Y318F substitution in the 3′ region of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been linked to nonnucleoside RT inhibitor (NNRTI) resistance in vitro. A systematic search of a large phenotypic-genotypic database (Virco) linked the Y318F substitution with a >10-fold decrease in NNRTI susceptibility in >85% of clinically derived isolates. There was a significant association between Y318F and use of delavirdine (P = 10−11) and nevirapine (P = 10−6) but not efavirenz (P = 0.3). Site-directed HIV-1 Y318F mutants in an HXB2 background displayed 42-fold-decreased susceptibility to delavirdine but <3-fold-decreased susceptibility to nevirapine or efavirenz. Combinations of Y318F with K103N, Y181C, or both resulted in decreased efavirenz susceptibility of 43-, 3.3-, and 84-fold, respectively, as well as >100- and >60-fold decreases in delavirdine and nevirapine susceptibility, respectively. These results indicate the importance of the Y318F substitution in HIV-1 drug resistance.

1998 ◽  
Vol 9 (5) ◽  
pp. 412-421 ◽  
Author(s):  
C Chamorro ◽  
M-J Camarasa ◽  
M-J Pérez-Pérez ◽  
E de Clercq ◽  
J Balzarini ◽  
...  

Novel derivatives of the potent human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitor TSAO-T have been designed, synthesized and tested for their in vitro antiretro-viral activity against HIV. These TSAO-T derivatives have been designed as potential bidentate inhibitors of HIV-1 RT, which combine in their structure the functionality of a non-nucleoside RT inhibitor (TSAO-T) and a bivalent ion-chelating moiety (a β-diketone moiety) linked through an appropriate spacer to the N-3 of thymine of TSAO-T . Some of the new compounds have an anti-HIV-1 activity comparable to that of the parent compound TSAO-T, but display a markedly increased antiviral selectivity. There was a clear relationship between antiviral activity and the length of the spacer group that links the TSAO molecule with the chelating moiety. A shorter spacer invariably resulted in increased antiviral potency. None of the TSAO-T derivatives were endowed with anti-HIV-2 activity.


2007 ◽  
Vol 81 (20) ◽  
pp. 11507-11519 ◽  
Author(s):  
Francesca Ceccherini-Silberstein ◽  
Valentina Svicher ◽  
Tobias Sing ◽  
Anna Artese ◽  
Maria Mercedes Santoro ◽  
...  

ABSTRACT Resistance to antivirals is a complex and dynamic phenomenon that involves more mutations than are currently known. Here, we characterize 10 additional mutations (L74V, K101Q, I135M/T, V179I, H221Y, K223E/Q, and L228H/R) in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase which are involved in the regulation of resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs). These mutations are strongly associated with NNRTI failure and strongly correlate with the classical NNRTI resistance mutations in a data set of 1,904 HIV-1 B-subtype pol sequences from 758 drug-naïve patients, 592 nucleoside reverse transcriptase inhibitor (NRTI)-treated but NNRTI-naïve patients, and 554 patients treated with both NRTIs and NNRTIs. In particular, L74V and H221Y, positively correlated with Y181C, were associated with an increase in Y181C-mediated resistance to nevirapine, while I135M/T mutations, positively correlated with K103N, were associated with an increase in K103N-mediated resistance to efavirenz. In addition, the presence of the I135T polymorphism in NNRTI-naïve patients significantly correlated with the appearance of K103N in cases of NNRTI failure, suggesting that I135T may represent a crucial determinant of NNRTI resistance evolution. Molecular dynamics simulations show that I135T can contribute to the stabilization of the K103N-induced closure of the NNRTI binding pocket by reducing the distance and increasing the number of hydrogen bonds between 103N and 188Y. H221Y also showed negative correlations with type 2 thymidine analogue mutations (TAM2s); its copresence with the TAM2s was associated with a higher level of zidovudine susceptibility. Our study reinforces the complexity of NNRTI resistance and the significant interplay between NRTI- and NNRTI-selected mutations. Mutations beyond those currently known to confer resistance should be considered for a better prediction of clinical response to reverse transcriptase inhibitors and for the development of more efficient new-generation NNRTIs.


1997 ◽  
Vol 8 (4) ◽  
pp. 353-362 ◽  
Author(s):  
SW Baertschi ◽  
AS Cantrell ◽  
MT Kuhfeld ◽  
U Lorenz ◽  
DB Boyd ◽  
...  

Previous work by Hafkemeyer et al. (1991) [ Nucleic Acids Research19: 4059–4065] indicated that a degradation product of ceftazidime, termed HP 0.35, was active against the RNase H activity of human immunodeficiency virus type 1 (HIV-1) and feline immunodeficiency virus (FIV) reverse transcriptase (RT) in vitro. Attempting to repeat these results, we isolated HP 0.35 from an aqueous degradation of ceftazidime and, after careful purification, we found HP 0.35 to be essentially inactive against both the polymerase and RNase H domains of HIV-1 RT (IC50 of >100 μg mL−1). During the investigation we discovered that polymeric degradation products of ceftazidime inhibited both the polymerase and, to a greater extent, the RNase H activities of HIV-1 RT in vitro (IC50 approximately 0.1 and 0.01 μg mL−1, respectively). Subjecting HP 0.35 to conditions under which it could polymerize induced inhibitory activity similar to that of the polymeric ceftazidime degradation products. It is proposed that the previously reported activity of HP 0.35 may have resulted from the presence of low levels of polymeric material either from incomplete purification or from polymerization of HP 0.35 during storage or in vitro testing.


2010 ◽  
Vol 55 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Yasuhiro Koh ◽  
Hillel Haim ◽  
Alan Engelman

ABSTRACTPharmacokinetic and pharmacodynamic considerations significantly impact infectious disease treatment options. One aspect of pharmacodynamics is the postantibiotic effect, classically defined as delayed bacterial growth after antibiotic removal. The same principle can apply to antiviral drugs. For example, significant delays in human immunodeficiency virus type 1 (HIV-1) replication can be observed after nucleoside/nucleotide reverse transcriptase inhibitor (N/NtRTI) removal from culture medium, because these prodrugs must be anabolized into active, phosphorylated forms once internalized into cells. A relatively new class of anti-HIV-1 drugs is the integrase strand transfer inhibitors (INSTIs), and the INSTIs raltegravir (RAL) and elvitegravir (EVG) were tested here alongside positive N/NtRTI controls tenofovir disoproxil fumarate (TDF) and azidothymidine (AZT), as well as the nonnucleoside reverse transcriptase inhibitor negative control nevirapine (NVP), to assess potential postantiviral effects. Transformed and primary CD4-positive cells pretreated with INSTIs significantly resisted subsequent challenge by HIV-1, revealing the following hierarchy of persistent intracellular drug strength: TDF > EVG ∼ AZT > RAL > NVP. A modified time-of-addition assay was moreover developed to assess residual drug activity levels. Approximately 0.8% of RAL and 2% of initial EVG and TDF 1-h pulse drug levels persisted during the acute phase of HIV-1 infection. EVG furthermore displayed significant virucidal activity. Although there is no reason to suspect obligate intracellular modification, this study nevertheless defines significant intracellular persistence of prototype INSTIs. Ongoing second-generation formulations should therefore consider the potential for significant postantiviral effects among this drug class. Combined intracellular persistence and virucidal activities suggest potential pre-exposure prophylaxis applications for EVG.


2002 ◽  
Vol 46 (11) ◽  
pp. 3613-3616 ◽  
Author(s):  
Fatih M. Uckun ◽  
Sharon Pendergrass ◽  
T. K. Venkatachalam ◽  
Sanjive Qazi ◽  
Douglas Richman

ABSTRACT We report the antiretroviral activity of stavudine-5′-(p-bromophenyl methoxyalaninyl phosphate) (stampidine [STAMP]), a novel aryl phosphate derivative of stavudine, against primary clinical human immunodeficiency virus type 1 (HIV-1) isolates. STAMP inhibited each one of nine clinical HIV-1 isolates of non-B envelope subtype and 20 genotypically and phenotypically nucleoside analog reverse transcriptase inhibitor-resistant HIV-1 isolates at subnanomolar to low-nanomolar concentrations.


1995 ◽  
Vol 6 (2) ◽  
pp. 73-79 ◽  
Author(s):  
M. Seki ◽  
Y. Sadakata ◽  
S. Yuasa ◽  
M. Baba

MKC-442, 6-benzy 1-1-ethoxymethyl-5-isopropyIuraciI (l-EBU), is a potent and selective non-nucleoside inhibitor of human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT). Nevirapine, another non-nucleoside RT inhibitor (NNRTI), is associated with rapid emergence of drug-resistant variants during in vitro passages of HIV-1. The emergence of resistant viruses to MKC-442 or nevirapine was examined in vitro. MT-4 cells infected with a clinical isolate (HE) of HIV-1 were cultivated in medium containing excess concentrations of these drugs, and the drug susceptibilities of the breakthrough viruses recovered from the medium were measured. Although nevirapine lost its antiviral activity after six passages, a delay in the emergence of fully resistant viruses was observed for MKC-442. Two resistant clones for each drug were isolated and nucleotide sequences within the RT region were analysed. An amino acid substitution at position 181 (Tyr to Cys) was found, with additional substitutions at positions 103 (Lys to Arg) and 108 (Val to lle) in the MKC-442-resistant viruses. These clones showed various susceptibilities to MKC-442, and cross-resistance to other NNRTIs but not to AZT. These results suggest that the major binding site of MKC-442 on the HIV-1 RT is the tyrosine residue common to these NNRTIs, and that drug resistance to NNRTIs is dependent on both the quality and the quantity of mutations within the HIV-1 RT gene.


2010 ◽  
Vol 54 (10) ◽  
pp. 4451-4463 ◽  
Author(s):  
Romuald Corbau ◽  
Julie Mori ◽  
Chris Phillips ◽  
Lesley Fishburn ◽  
Alex Martin ◽  
...  

ABSTRACT The nonnucleoside reverse transcriptase inhibitors (NNRTIs) are key components of highly active antiretroviral therapy (HAART) for the treatment of human immunodeficiency virus type 1 (HIV-1). A major problem with the first approved NNRTIs was the emergence of mutations in the HIV-1 reverse transcriptase (RT), in particular K103N and Y181C, which led to resistance to the entire class. We adopted an iterative strategy to synthesize and test small molecule inhibitors from a chemical series of pyrazoles against wild-type (wt) RT and the most prevalent NNRTI-resistant mutants. The emerging candidate, lersivirine (UK-453,061), binds the RT enzyme in a novel way (resulting in a unique resistance profile), inhibits over 60% of viruses bearing key RT mutations, with 50% effective concentrations (EC50s) within 10-fold of those for wt viruses, and has excellent selectivity against a range of human targets. Altogether lersivirine is a highly potent and selective NNRTI, with excellent efficacy against NNRTI-resistant viruses.


Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 495
Author(s):  
Mai Izumida ◽  
Koushirou Suga ◽  
Fumito Ishibashi ◽  
Yoshinao Kubo

In this study, we aimed to find chemicals from lower sea animals with defensive effects against human immunodeficiency virus type 1 (HIV-1). A library of marine natural products consisting of 80 compounds was screened for activity against HIV-1 infection using a luciferase-encoding HIV-1 vector. We identified five compounds that decreased luciferase activity in the vector-inoculated cells. In particular, portimine, isolated from the benthic dinoflagellate Vulcanodinium rugosum, exhibited significant anti-HIV-1 activity. Portimine inhibited viral infection with an 50% inhibitory concentration (IC50) value of 4.1 nM and had no cytotoxic effect on the host cells at concentrations less than 200 nM. Portimine also inhibited vesicular stomatitis virus glycoprotein (VSV-G)-pseudotyped HIV-1 vector infection. This result suggested that portimine mainly targeted HIV-1 Gag or Pol protein. To analyse which replication steps portimine affects, luciferase sequences were amplified by semi-quantitative PCR in total DNA. This analysis revealed that portimine inhibits HIV-1 vector infection before or at the reverse transcription step. Portimine has also been shown to have a direct effect on reverse transcriptase using an in vitro reverse transcriptase assay. Portimine efficiently inhibited HIV-1 replication and is a potent lead compound for developing novel therapeutic drugs against HIV-1-induced diseases.


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