scholarly journals Dolutegravir impairs stem cell-based 3D morphogenesis models in a manner dependent on dose and timing of exposure: an implication for its developmental toxicity

2021 ◽  
Author(s):  
Lauren Kirkwood-Johnson ◽  
Nana Katayama ◽  
Yusuke Marikawa
Keyword(s):  
Stem Cells ◽  
Animal Studies ◽  
Expression Profiles ◽  
Developmental Toxicity ◽  
Strand Transfer ◽  
In Vitro Morphogenesis ◽  
Transfer Inhibitor ◽  
Timing Of Exposure ◽  
Integrase Strand Transfer Inhibitor

Abstract Dolutegravir is an anti-retroviral drug of the integrase strand transfer inhibitor class used to treat HIV infection. It is the recommended first-line regimen for most people, including women of childbearing age. However, some human and animal studies have suggested that dolutegravir causes birth defects, although its developmental toxicity remains controversial. Here, we investigated the adverse effects of dolutegravir using pluripotent stem cell-based in vitro morphogenesis models that have previously been validated as effective tools to assess the developmental toxicity of various chemicals. Dolutegravir diminished the growth and axial elongation of the morphogenesis model of mouse pluripotent stem cells at exposures of 2 μM and above in a concentration-dependent manner. Concomitantly, dolutegravir altered the expression profiles of developmental regulator genes involved in embryonic patterning. The adverse effects were observed when the morphogenesis model was exposed to dolutegravir at early stages of development, but not at later stages. The potency and molecular impact of dolutegravir on the morphogenesis model were distinct from other integrase strand transfer inhibitors. Lastly, dolutegravir altered the growth and gene expression profiles of the morphogenesis model of human embryonic stem cells at 1 μM and above. These studies demonstrate that dolutegravir impairs morphological and molecular aspects of the in vitro morphogenesis models in a manner dependent on dose and timing of exposure through mechanisms that are unrelated to its action as an integrase strand transfer inhibitor. This finding will be useful for interpreting the conflicting outcomes regarding the developmental toxicity of dolutegravir in human and animal studies.

scholarly journals In SilicoandIn VitroComparison of HIV-1 Subtypes B and CRF02_AG Integrases Susceptibility to Integrase Strand Transfer Inhibitors

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaoju Ni ◽  
Safwat Abdel-Azeim ◽  
Elodie Laine ◽  
Rohit Arora ◽  
Osamuede Osemwota ◽  
...  
Keyword(s):  
Structural Features ◽  
Strand Transfer ◽  
Binding Modes ◽  
Medical Treatments ◽  
Sequence Variations ◽  
Transfer Inhibitor ◽  
Dna Substrate ◽  
Integrase Strand Transfer Inhibitor ◽  
Hiv 1

Most antiretroviral medical treatments were developed and tested principally on HIV-1 B nonrecombinant strain, which represents less than 10% of the worldwide HIV-1-infected population. HIV-1 circulating recombinant form CRF02_AG is prevalent in West Africa and is becoming more frequent in other countries. Previous studies suggested that the HIV-1 polymorphisms might be associated to variable susceptibility to antiretrovirals. This study is pointed to compare the susceptibility to integrase (IN) inhibitors of HIV-1 subtype CRF02_AG IN respectively to HIV-1 B. Structural models of B and CRF02_AG HIV-1 INs as unbound enzymes and in complex with the DNA substrate were built by homology modeling. IN inhibitors—raltegravir (RAL), elvitegravir (ELV) and L731,988—were docked onto the models, and their binding affinity for both HIV-1 B and CRF02_AG INs was compared. CRF02_AG INs were cloned and expressed from plasma of integrase strand transfer inhibitor (INSTI)-naïve infected patients. Ourin silicoandin vitrostudies showed that the sequence variations between the INs of CRF02_AG and B strains did not lead to any notable difference in the structural features of the enzyme and did not impact the susceptibility to the IN inhibitors. The binding modes and affinities of INSTI inhibitors to B and CRF02_AG INs were found to be similar. Although previous studies suggested that several naturally occurring variations of CRF02_AG IN might alter either IN/vDNA interactions or INSTIs binding, our study demonstrate that these variations do affect neither IN activity nor its susceptibility to INSTIs.

scholarly journals A systematic review of the genetic mechanisms of dolutegravir resistance

2019 ◽  
Vol 74 (11) ◽  
pp. 3135-3149 ◽  
Author(s):  
Soo-Yon Rhee ◽  
Philip M Grant ◽  
Philip L Tzou ◽  
Geoffrey Barrow ◽  
P Richard Harrigan ◽  
...  
Keyword(s):  
Strand Transfer ◽  
Resistance Mutations ◽  
First Line Therapy ◽  
Highly Effective ◽  
Active Viral Replication ◽  
Drug Regimens ◽  
Genetic Mechanisms ◽  
Transfer Inhibitor ◽  
Integrase Strand Transfer Inhibitor

Abstract Background Characterizing the mutations selected by the integrase strand transfer inhibitor (INSTI) dolutegravir and their effects on susceptibility is essential for identifying viruses less likely to respond to dolutegravir therapy and for monitoring persons with virological failure (VF) on dolutegravir therapy. Methods We systematically reviewed dolutegravir resistance studies to identify mutations emerging under dolutegravir selection pressure, the effect of INSTI resistance mutations on in vitro dolutegravir susceptibility, and the virological efficacy of dolutegravir in antiretroviral-experienced persons. Results and conclusions We analysed 14 studies describing 84 in vitro passage experiments, 26 studies describing 63 persons developing VF plus INSTI resistance mutations on a dolutegravir-containing regimen, 41 studies describing dolutegravir susceptibility results, and 22 clinical trials and 16 cohort studies of dolutegravir-containing regimens. The most common INSTI resistance mutations in persons with VF on a dolutegravir-containing regimen were R263K, G118R, N155H and Q148H/R, with R263K and G118R predominating in previously INSTI-naive persons. R263K reduced dolutegravir susceptibility ∼2-fold. G118R generally reduced dolutegravir susceptibility >5-fold. The highest levels of reduced susceptibility occurred in viruses containing Q148 mutations in combination with G140 and/or E138 mutations. Dolutegravir two-drug regimens were highly effective for first-line therapy and for virologically suppressed persons provided dolutegravir’s companion drug was fully active. Dolutegravir three-drug regimens were highly effective for salvage therapy in INSTI-naive persons provided one or more of dolutegravir’s companion drugs was fully active. However, dolutegravir monotherapy in virologically suppressed persons and functional dolutegravir monotherapy in persons with active viral replication were associated with a non-trivial risk of VF plus INSTI resistance mutations.

scholarly journals Structural basis for the inhibition of HTLV-1 integration inferred from cryo-EM deltaretroviral intasome structures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michal S. Barski ◽  
Teresa Vanzo ◽  
Xue Zhi Zhao ◽  
Steven J. Smith ◽  
Allison Ballandras-Colas ◽  
...  
Keyword(s):  
Structural Basis ◽  
Strand Transfer ◽  
Coordination Environment ◽  
Human T Cell ◽  
Life Threatening ◽  
Transfer Inhibitor ◽  
Exposure Prophylaxis ◽  
Integrase Strand Transfer Inhibitor

AbstractBetween 10 and 20 million people worldwide are infected with the human T-cell lymphotropic virus type 1 (HTLV-1). Despite causing life-threatening pathologies there is no therapeutic regimen for this deltaretrovirus. Here, we screened a library of integrase strand transfer inhibitor (INSTI) candidates built around several chemical scaffolds to determine their effectiveness in limiting HTLV-1 infection. Naphthyridines with substituents in position 6 emerged as the most potent compounds against HTLV-1, with XZ450 having highest efficacy in vitro. Using single-particle cryo-electron microscopy we visualised XZ450 as well as the clinical HIV-1 INSTIs raltegravir and bictegravir bound to the active site of the deltaretroviral intasome. The structures reveal subtle differences in the coordination environment of the Mg2+ ion pair involved in the interaction with the INSTIs. Our results elucidate the binding of INSTIs to the HTLV-1 intasome and support their use for pre-exposure prophylaxis and possibly future treatment of HTLV-1 infection.

scholarly journals Effects of Raltegravir or Elvitegravir Resistance Signature Mutations on the Barrier to Dolutegravir ResistanceIn Vitro

2015 ◽  
Vol 59 (5) ◽  
pp. 2596-2606 ◽  
Author(s):  
Takahiro Seki ◽  
Akemi Suyama-Kagitani ◽  
Shinobu Kawauchi-Miki ◽  
Shigeru Miki ◽  
Chiaki Wakasa-Morimoto ◽  
...  
Keyword(s):  
Viral Replication ◽  
Partial Recovery ◽  
Strand Transfer ◽  
Resistance Selection ◽  
Development Of Resistance ◽  
Low Concentrations ◽  
Transfer Inhibitor ◽  
Integrase Strand Transfer Inhibitor ◽  
Hiv 1

ABSTRACTThe recently approved HIV-1 integrase strand transfer inhibitor (INSTI) dolutegravir (DTG) (S/GSK1349572) has overall advantageous activity when testedin vitroagainst HIV-1 with raltegravir (RAL) and elvitegravir (EVG) resistance signature mutations. We conducted anin vitroresistance selection study using wild-type HIV-1 and mutants with the E92Q, Y143C, Y143R, Q148H, Q148K, Q148R, and N155H substitutions to assess the DTGin vitrobarrier to resistance. No viral replication was observed at concentrations of ≥32 nM DTG, whereas viral replication was observed at 160 nM RAL or EVG in the mutants. In the Q148H, Q148K, or Q148R mutants, G140S/Q148H, E138K/Q148K, E138K/Q148R, and G140S/Q148R secondary mutations were identified with each INSTI and showed high resistance to RAL or EVG but limited resistance to DTG. E138K and G140S, as secondary substitutions to Q148H, Q148K, or Q148R, were associated with partial recovery in viral infectivity and/or INSTI resistance. In the E92Q, Y143C, Y143R, and N155H mutants, no secondary substitutions were associated with DTG. Thesein vitroresults suggest that DTG has a high barrier to the development of resistance in the presence of RAL or EVG signature mutations other than Q148. One explanation for this high barrier to resistance is that no additional secondary substitution of E92Q, Y143C, Y143R, or N155H simultaneously increased the fold change in 50% effective concentration (EC50) to DTG and infectivity. Although increased DTG resistance via the Q148 pathway and secondary substitutions occurs at low concentrations, a higher starting concentration may reduce or eliminate the development of DTG resistance in this pathwayin vitro.

The Use of Biomarkers as Alternatives to Current Animal Tests on Food Chemicals

1998 ◽  
Vol 26 (4) ◽  
pp. 421-480
Author(s):  
Krys Bottrill
Keyword(s):  
Animal Studies ◽  
Developmental Toxicity ◽  
Reproductive Toxicity ◽  
In Vitro Test ◽  
Animal Testing ◽  
Dietary Biomarkers ◽  
Recent Developments ◽  
Mechanistic Basis ◽  
The Three Rs

Recent developments in biomarkers relating to the interrelationship of diet, disease and health were surveyed. Most emphasis was placed on biomarkers of deleterious effects, since these are of greatest relevance to the subject of this review. The area of greatest activity was found to be that relating to biomarkers of mutagenic, genotoxic and carcinogenic effects. This is also one of the major areas of concern in considerations of the beneficial and deleterious effects of dietary components, and also the area in which regulatory testing requires studies of the longest duration. A degree of progress has also been made in the identification and development of biomarkers relating to certain classes of target organ toxicity. Biomarkers for other types of toxicity, such as immunotoxicity, neurotoxicity, reproductive toxicity and developmental toxicity, are less developed, and further investigation in these areas is required before a comprehensive biomarker strategy can be established. A criticism that recurs constantly in the biomarker literature is the lack of standardisation in the methods used, and the lack of reference standards for the purposes of validation and quality control. It is encouraging to note the growing acknowledgement of the need for validation of biomarkers and biomarker assays. Some validation studies have already been initiated. This review puts forward proposals for criteria to be used in biomarker validation. More discussion on this subject is required. It is concluded that the use of biomarkers can, in some cases, facilitate the implementation of the Three Rs with respect to the testing of food chemicals and studies on the effects of diet on health. The greatest potential is seen to be in the refinement of animal testing, in which biomarkers could serve as early and sensitive endpoints, in order to reduce the duration of the studies and also reduce the number of animals required. Biomarkers could also contribute to establishing a mechanistic basis for in vitro test systems and to facilitating their validation and acceptance. Finally, the increased information that could result from the incorporation of biomarker determinations into population studies could reduce the need for supplementary animal studies. This review makes a number of recommendations concerning the prioritisation of future activities on dietary biomarkers in relation to the Three Rs. It is emphasised, however, that further discussions will be required among toxicologists, epidemiologists and others researching the relationship between diet and health.

Inflammatory Myositis Secondary to Anti-Retroviral Therapy in a Child; Case Report and Review of the Literature

2021 ◽  
pp. 1-7
Author(s):  
Marie Monaghan ◽  
Charlotte Loh ◽  
Stephen Jones ◽  
Agyepong Oware ◽  
Kathryn Urankar ◽  
...  
Keyword(s):  
Drug Regimen ◽  
Dramatic Improvement ◽  
Strand Transfer ◽  
Inflammatory Myositis ◽  
Once Daily ◽  
Immune Mediated ◽  
Show Evidence ◽  
Transfer Inhibitor ◽  
Integrase Strand Transfer Inhibitor

Here, we describe a five year old girl with congenital HIV who had a six-week onset of rapidly deteriorating mobility and progressive proximal muscle weakness, associated with a raised Creatine Kinase (CK) level of 4330 U/L [25–200 U/L], subsequently diagnosed with an inflammatory myositis. Potential causes were investigated by paediatric neurology and immunology teams. Her viral load had been undetectable over the preceding two years, excluding a primary HIV myositis. While MRI scanning did not show evidence of definite myositis, a muscle biopsy showed evidence of an inflammatory process, comprising a moderate endomysial, perimysial and perivascular mononuclear (CD8 + T cell) infiltrate with increased MHC expression. No particular features of dermatomyositis or immune-mediated necrotising myopathy were identified and there were no features of an inclusion body myositis. Given the absence of active HIV infection, the role of anti-retroviral medications was considered. She had had a recent switch in medication, from twice daily Raltegravir (an Integrase Strand Transfer Inhibitor, INSTI) to once daily Dolutegravir (an INSTI) while continuing on an established daily protocol of Abacavir and Lamivudine (Nucleoside Reverse Transcriptase Inhibitors). Changing the Dolutegravir back to Raltegravir, in combination with continuing Lamivudine and Abacavir for two months made no difference to her weakness or CK levels. Moreover, this drug regimen had been well-tolerated over the preceding 19 month period. Changing the anti-retroviral regime completely to a single drug class (Protease Inhibitors) of Ritonavir and Darunavir, resulted in a dramatic improvement in her symptomatology. Within ten days she regained the ability to stand and walk, with a reduction in her CK from 1700 U/L at time of switch to 403 U/L [25–200]. This case highlights the potential risk of developing inflammatory myositis from anti-retrovirals even 19 months into treatment.

Progressive emergence of an S153F plus R263K combination of integrase mutations in the proviral DNA of one individual successfully treated with dolutegravir

2020 ◽  
Author(s):  
Hanh T Pham ◽  
Brunna M Alves ◽  
Sunbin Yoo ◽  
Meng A Xiao ◽  
Jing Leng ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Dna Binding ◽  
Drug Resistant ◽  
Strand Transfer ◽  
Viral Genomes ◽  
Proviral Dna ◽  
Viral Loads ◽  
Subtype B ◽  
Transfer Inhibitor ◽  
Integrase Strand Transfer Inhibitor

Abstract Objectives The development of HIV drug resistance against the integrase strand transfer inhibitor dolutegravir is rare. We report here the transient detection, by near full-genome ultradeep sequencing, of minority HIV-1 subtype B variants bearing the S153F and R263K integrase substitutions in the proviral DNA from blood cells of one patient who successfully initiated dolutegravir-based ART, over 24 weeks. Our objective was to study the effects of these substitutions. Methods Strand transfer and DNA-binding activities of recombinant integrase proteins were measured in cell-free assays. Cell-based resistance, infectivity and replicative capacities were measured using molecular clones. Structural modelling was performed to understand experimental results. Results R263K emerged first, followed by the addition of S153F at Week 12. By Week 24, both mutations remained present, but at lower prevalence. We confirmed the coexistence of S153F and R263K on single viral genomes. Combining S153F or S153Y with R263K decreased integration and viral replicative capacity and conferred high levels of drug resistance against all integrase inhibitors. Alone, S153Y and S153F did little to infectivity or dolutegravir resistance. We identified altered DNA binding as a mechanism of resistance. The patient remained with undetectable viral loads at all timepoints. Conclusions Drug-resistant minority variants have often been reported under suppressive ART. Our study adds to these observations by unravelling a progression towards higher levels of resistance through a novel pathway despite continuous undetectable viral loads. Poorly replicative HIV drug-resistant minority proviral variants did not compromise viral suppression in one individual treated with dolutegravir.

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