scholarly journals Tackling the problem of HIV drug resistance

2016 ◽  
Vol 62 (3) ◽  
pp. 273-279
Author(s):  
Irene T. Weber ◽  
Robert W. Harrison

The virally-encoded HIV-1 protease is an effective target for antiviral drugs, however, treatment for HIV infections is limited by the prevalence of drug resistant viral mutants. In this review, we describe our three-pronged approach to analyze and combat drug resistance. Understanding the molecular basis for resistance due to protease inhibitors is a key initial step in this approach. This knowledge is being employed for the design of new, improved inhibitors with high affinity for resistant mutants as well as wild type enzyme. In parallel with experimental studies of diverse mutants and inhibitory compounds, we are developing efficient algorithms to predict drug resistance phenotype from genotype data. This approach has important practical applications in the clinic where genotyping is recommended for individuals with new infections.

2019 ◽  
Author(s):  
Mariano Avino ◽  
Emmanuel Ndashimye ◽  
Daniel J. Lizotte ◽  
Abayomi S. Olabode ◽  
Richard M. Gibson ◽  
...  

AbstractThe global HIV-1 pandemic comprises many genetically divergent subtypes. Most of our understanding of drug resistance in HIV-1 derives from subtype B, which predominates in North America and western Europe. However, about 90% of the pandemic represents non-subtype B infections. Here, we use deep sequencing to analyze HIV-1 from infected individuals in Uganda who were either treatment-naïve or who experienced virologic failure on ART without the expected patterns of drug resistance. Our objective was to detect potentially novel associations between mutations in HIV-1 integrase and treatment outcomes in Uganda, where most infections are subtypes A or D. We retrieved a total of 380 archived plasma samples from patients at the Joint Clinical Research Centre (Kampala), of which 328 were integrase inhibitor-naïve and 52 were raltegravir (RAL)-based treatment failures. Next, we developed a bioinformatic pipeline for alignment and variant calling of the deep sequence data obtained from these samples from a MiSeq platform (Illumina). To detect associations between within-patient polymorphisms and treatment outcomes, we used a support vector machine (SVM) for feature selection with multiple imputation to account for partial reads and low quality base calls. Candidate point mutations of interest were experimentally introduced into the HIV-1 subtype B NL4-3 backbone to determine susceptibility to RAL in U87.CD4.CXCR4 cells. Finally, we carried out replication capacity experiments with wild-type and mutant viruses in TZM-bl cells in the presence and absence of RAL. Our analyses not only identified the known major mutation N155H and accessory mutations G163R and V151I, but also novel mutations I203M and I208L as most highly associated with RAL failure. The I203M and I208L mutations resulted in significantly decreased susceptibility to RAL (44.0-fold and 54.9-fold, respectively) compared to wild-type virus (EC50=0.32 nM), and may represent novel pathways of HIV-1 resistance to modern treatments.Author summaryThere are many different types of HIV-1 around the world. Most of the research on how HIV-1 can become resistant to drug treatment has focused on the type (B) that is the most common in high-income countries. However, about 90% of infections around the world are caused by a type other than B. We used next-generation sequencing to analyze samples of HIV-1 from patients in Uganda (mostly infected by types A and D) for whom drug treatment failed to work, and whose infections did not fit the classic pattern of adaptation based on B. Next, we used machine learning to detect mutations in these virus populations that could explain the treatment outcomes. Finally, we experimentally added two candidate mutations identified by our analysis to a laboratory strain of HIV-1 and confirmed that they conferred drug resistance to the virus. Our study reveals new pathways that other types of HIV-1 may use to evolve resistance to drugs that make up the current recommended treatment for newly diagnosed individuals.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Manabu Aoki ◽  
Debananda Das ◽  
Hironori Hayashi ◽  
Hiromi Aoki-Ogata ◽  
Yuki Takamatsu ◽  
...  

ABSTRACTDarunavir (DRV) has bimodal activity against HIV-1 protease, enzymatic inhibition and protease dimerization inhibition, and has an extremely high genetic barrier against development of drug resistance. We previously generated a highly DRV-resistant HIV-1 variant (HIVDRVRP51). We also reported that four amino acid substitutions (V32I, L33F, I54M, and I84V) identified in the protease of HIVDRVRP51are largely responsible for its high-level resistance to DRV. Here, we attempted to elucidate the role of each of the four amino acid substitutions in the development of DRV resistance. We found that V32I is a key substitution, which rarely occurs, but once it occurs, it predisposes HIV-1 to develop high-level DRV resistance. When two infectious recombinant HIV-1 clones carrying I54M and I84V (rHIVI54Mand rHIVI84V, respectively) were selected in the presence of DRV, V32I emerged, and the virus rapidly developed high-level DRV resistance. rHIVV32Ialso developed high-level DRV resistance. However, wild-type HIVNL4-3(rHIVWT) failed to acquire V32I and did not develop DRV resistance. Compared to rHIVWT, rHIVV32Iwas highly susceptible to DRV and had significantly reduced fitness, explaining why V32I did not emerge upon selection of rHIVWTwith DRV. When the only substitution is at residue 32, structural analysis revealed much stronger van der Waals interactions between DRV and I-32 than between DRV and V-32. These results suggest that V32I is a critical amino acid substitution in multiple pathways toward HIV-1’s DRV resistance development and elucidate, at least in part, a mechanism of DRV’s high genetic barrier to development of drug resistance. The results also show that attention should be paid to the initiation or continuation of DRV-containing regimens in people with HIV-1 containing the V32I substitution.IMPORTANCEDarunavir (DRV) is the only protease inhibitor (PI) recommended as a first-line therapeutic and represents the most widely used PI for treating HIV-1-infected individuals. DRV possesses a high genetic barrier to development of HIV-1’s drug resistance. However, the mechanism(s) of the DRV’s high genetic barrier remains unclear. Here, we show that the preexistence of certain single amino acid substitutions such as V32I, I54M, A71V, and I84V in HIV-1 protease facilitates the development of high-level DRV resistance. Interestingly, allin vitro-selected highly DRV-resistant HIV-1 variants acquired V32I but never emerged in wild-type HIV (HIVWT), and V32I itself rendered HIV-1 more sensitive to DRV and reduced viral fitness compared to HIVWT, strongly suggesting that the emergence of V32I plays a critical role in the development of HIV-1’s resistance to DRV. Our results would be of benefit in the treatment of HIV-1-infected patients receiving DRV-containing regimens.


2007 ◽  
Vol 50 (18) ◽  
pp. 4509-4515 ◽  
Author(s):  
Yuan-Fang Wang ◽  
Yunfeng Tie ◽  
Peter I. Boross ◽  
Jozsef Tozser ◽  
Arun K. Ghosh ◽  
...  

2018 ◽  
Author(s):  
Shahid N Khan ◽  
John D Persons ◽  
Michel Guerrero ◽  
Tatiana V. Ilina ◽  
Masayuki Oda ◽  
...  

AbstractSome of drug-resistant mutants of HIV-1 protease (PR), such as a clinically-relevant drug- resistant PR mutant (Flap+(I54V)) containing L10I, G48V, I54V and V82A mutations, produce significant changes in the balance between entropy and enthalpy of the drug-PR interactions, compared to the wild-type (WT) PR. Here, to gain a comprehensive understanding of the entropy-enthalpy compensation effects, we compared nuclear magnetic resonance (NMR), fluorescence spectroscopy and isothermal titration calorimetry (ITC) data of a WT PR with Flap+(I54V)and related mutants: (1) Flap+(I54V); (2) Flap+(I54A)which evolves from Flap+(I54V)in the continued presence of inhibitor yet does not exhibit entropy-enthalpy compensation; and (3) Flap+(I54), a control mutant that contains only L10I, G48V and V82A mutations. Our data indicate that WT and Flap+(I54A)show enthalpy-driven inhibitor-interaction, while Flap+(I54)and Flap+(I54V)exhibit entropy-driven inhibitor interaction. Interestingly, Flap+(I54A)exhibited significantly slower heat flow in the competitive ITC experiment with a strong binder, darunavir, and a weak binder, acetyl-pepstatin, but did not exhibit such slow heat flow in the direct inhibitor-titration experiments. NMR confirmed replacement of the weak binder by the strong binder in a competitive manner. This difference in the heat flow of the competitive binding experiment compared to the direct experiment can only be explained by assuming an inhibitor-bound intermediate pathway. A similar, but attenuated, tendency for slow heat flow was also detected in the competitive experiment with WT. Overall, our data suggests that an inhibitor-bound intermediate affects the entropy-enthalpy compensation of inhibitor-PR interaction.


2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Liyan Jiao ◽  
Hanping Li ◽  
Lin Li ◽  
Daomin Zhuang ◽  
Yongjian Liu ◽  
...  

Objective. To clarify the impact of H221Y mutation on drug resistance to NVP.Methods. 646 bp HIV-1polgene fragments (from 592 to 1237 nucleotide) with different NNRTIs mutation profiles from AIDS patients receiving antiretroviral therapy containing NVP regimens were introduced into pNL4-3 backbone plasmid. H221Y and (or) Y181C mutations were reverted to wild type amino acids by site-directed mutagenesis, then strains containing various mutation patterns were packaged. Phenotypic drug resistance was analyzed on TZM-bl cells.Results. 12 strains containing different drug-resistant mutation profiles were constructed, including the K101Q series (K101Q/Y181C/H221Y, K101Q/Y181C, K101Q/H221Y, and K101Q), the V179D series (V179D/Y181C/H221Y, V179D/Y181C, V179D/H221Y, and V179D), and the K103N series (K103N/Y181C/H221Y, K103N/Y181C, K103N/H221Y, K103N). For strains containing the mutation profiles (K101Q/Y181C, K101Q, V179D/Y181C, V179D, K103N/Y181C, and K103N), the presence of H221Y reduced NVP susceptibility by2.1±0.5to3.6±0.5fold. To the mutation profiles K101Q/H221Y, K101Q, V179D/H221Y, V179D, K103N/H221Y, and K103N, the presence of Y181C reduced NVP susceptibility by41.9±8.4to1297.0±289.1fold. For the strains containing K101Q, V179D, and K103N, the presence of Y181C/H221Y combination decreased NVP susceptibility by100.6±32.5to3444.6±834.5fold.Conclusion. On the bases of various NNRTIs mutation profiles, Y181C remarkably improved the IC50to NVP, although H221Ymutation alone just increases 2.1 ∼ 3.6-fold resistance to NVP, the mutation could improve 100.6 ∼ 3444.6-fold resistance to NVP when it copresent with Y181C, the phenotypic drug resistance fold was improved extremely. For strains containing the mutation profiles (K101Q/Y181C, K101Q, V179D/Y181C, V179D, K103N/Y181C, and K103N), the presence of H221Y reduced NVP susceptibility by2.1±0.5to3.6±0.5fold.


2002 ◽  
Vol 367 (2) ◽  
pp. 381-391 ◽  
Author(s):  
Michal ENTIN-MEER ◽  
Ziv SEVILYA ◽  
Amnon HIZI

Phe-119 in the reverse transcriptase (RT) of mouse mammary tumour virus (MMTV) is homologous with Tyr-115 in HIV type 1 (HIV-1) RT and to Phe-155 in murine leukaemia virus (MLV) RT. By mutating these residues in HIV-1 and MLV RTs (which are strict DNA polymerases) the enzymes were shown to function also as RNA polymerases. Owing to the uniqueness of MMTV as a type B retrovirus, we have generated a Phe-119—Val mutant of MMTV RT to study the involvement of this residue in affecting the catalytic features of this RT. The data presented here show that the mutant MMTV RT can incorporate both deoxyribonucleosides and ribonucleosides while copying either RNA or DNA. In addition, this mutant RT shows resistance to nucleoside analogues and an enhanced fidelity of DNA synthesis; all relative to the wild-type enzyme. The Phe-119—Val mutant is also different from the wild-type enzyme in its preference for most template primers tested and in its ability to synthesize DNA under non-processive and processive conditions. Overall, it is likely that the aromatic side chain of Phe-119 is located at the dNTP-binding site of MMTV RT and thus might be part of a putative ‘steric gate’ that prevents the incorporation of nucleoside triphosphates. Since the only three-dimensional structures of RTs published so far are those of HIV-1 and MLV, it is likely that MMTV RT folds quite similarly to these RTs.


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