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Mimtsoudis I, Tsachouridou O, Akinosoglou K, Metallidis S. Treatment Management Challenges in Naïve and Experienced HIV-1-Infected Individuals Carrying the M184V Mutation. Viruses 2024; 16:1392. [PMID: 39339868 PMCID: PMC11437411 DOI: 10.3390/v16091392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 08/12/2024] [Accepted: 08/22/2024] [Indexed: 09/30/2024] Open
Abstract
M184V is a single-base mutation in the YMDD domain of reverse transcriptase (RT). The M184V resistance-associated mutation (RAM) is related to virological unresponsiveness to lamivudine (3TC) and emtricitabine (FTC) and induces high-level resistance to these two antiretroviral agents. M184V is rapidly selected in the setting of non-suppressive antiretroviral therapy (ART) and accumulates in the HIV reservoir. There were continuous efforts to evaluate the impact of the M184V mutation on the treatment outcomes in people living with HIV (PLWH). Since 3TC remains an extensively used part of recommended antiretroviral combinations, M184V is commonly detected in patients with virological failure (VF). ART guidelines do not recommend the use of drugs impacted by RAMs as they have been confirmed to comprise a risk factor for VF. However, there is evidence that 3TC/FTC can remain active even in the presence of M184V. Given the potential benefits of 3TC in ART combinations, the investigation of M184V remains of high interest to clinicians and researchers, especially in certain regions with limited resources, and especially for its unusual effects. This is a review of the literature on the challenges in treating both naïve and experienced individuals carrying the M184V mutation, including virological failure, virological suppression, and resistance to ART.
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Affiliation(s)
- Iordanis Mimtsoudis
- Infectious Diseases Division 1st Internal Medicine Department, AHEPA University Hospital Thessaloniki, 54636 Thessaloniki, Greece; (I.M.); (S.M.)
| | - Olga Tsachouridou
- Infectious Diseases Division 1st Internal Medicine Department, AHEPA University Hospital Thessaloniki, 54636 Thessaloniki, Greece; (I.M.); (S.M.)
| | - Karolina Akinosoglou
- Department of Internal Medicine and Infectious Diseases, University General Hospital of Patras, 26504 Patras, Greece;
| | - Symeon Metallidis
- Infectious Diseases Division 1st Internal Medicine Department, AHEPA University Hospital Thessaloniki, 54636 Thessaloniki, Greece; (I.M.); (S.M.)
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Lan Y, Li F, Li L, Deng X, Li L, Li J, Cai X, Ling X, Hu F. OUP accepted manuscript. J Antimicrob Chemother 2022; 77:1960-1968. [PMID: 35484082 DOI: 10.1093/jac/dkac132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/01/2022] [Indexed: 11/12/2022] Open
Affiliation(s)
- Yun Lan
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
| | - Feng Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
| | - Linghua Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
| | - Xizi Deng
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
| | - Liya Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
| | - Junbin Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
- Guangdong Center for Diagnosis and Treatment of AIDS, 627 Dongfeng East Road, Yuexiu District, Guangzhou, 510060, China
| | - Xiaoli Cai
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
| | - Xuemei Ling
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
- Guangdong Center for Diagnosis and Treatment of AIDS, 627 Dongfeng East Road, Yuexiu District, Guangzhou, 510060, China
| | - Fengyu Hu
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China
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Lan Y, Deng X, Li L, Cai W, Li J, Cai X, Li F, Hu F, Lei C, Tang X. HIV-1 Drug Resistance and Genetic Transmission Networks Among MSM Failing Antiretroviral Therapy in South China 2014-2019. Infect Drug Resist 2021; 14:2977-2989. [PMID: 34377002 PMCID: PMC8349545 DOI: 10.2147/idr.s317187] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/21/2021] [Indexed: 01/05/2023] Open
Abstract
Background Guangdong, located in South China, is one of the areas heavily affected by HIV-1 in China. The transmission of HIV-1 among men who have sex with men (MSM) has gradually been increasing in Guangdong. Objective To investigate the characteristics of the HIV-1 drug resistance, and genetic transmission networks in MSM with antiretroviral therapy (ART) failure from 2014 to 2019 in Guangdong. Methods HIV-1 pol gene sequences were amplified. An online subtyping tool was used to determine the genotype, and a maximum likelihood phylogenetic tree was reconstructed to confirm the genotype results. The Stanford University HIV Drug Resistance Database was used to analyse the sequences of drug resistance mutations (DRMs) and drug resistance profiles. A pairwise Tamura-Nei 93 genetic distance-based method was used to analyse the genetic transmission networks. Results Of 393 sequences isolated from HIV-infected MSM with ART failure, CRF01_AE (47.3%), CRF07_BC (21.4%) and CRF55_01B (21.4%) were the top three strains. 55.2% individuals harboured NRTI DRMs, whereas 67.4% carried NNRTI DRMs. 96.8% cases harboured mutations resistance to NRTIs or NNRTIs at high-level. The most common DRMs were M184I/V (42.2%), followed by V179D/E (37.9%) and K65R (27.2%). Of the subtype B sequences, no sequence fell into a cluster. Of the CRF01_AE, CRF55_01B, and CRF59_01B sequences, 14.5%, 61.9%, and 33.3% fell into clusters, respectively. Of the CRF07_BC sequences, 39.3% fell into clusters. The majority of MSM in transmission networks were concentrated at age below 35 years old, with multiple links. Moreover, approximately 54.8% of MSM had more than 2 potential transmission partners. Conclusion Drug resistance mutations more frequently occurred in NNRTIs among MSM with ART failure in Guangdong Province. Transmission network analysis revealed a complex transmission pattern, and more attention should be given to younger HIV-1-infected MSM with multiple links.
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Affiliation(s)
- Yun Lan
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Xizi Deng
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Linghua Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Weiping Cai
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Junbin Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Xiaoli Cai
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Feng Li
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Fengyu Hu
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Chunliang Lei
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
| | - Xiaoping Tang
- Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou, 510030, People's Republic of China
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Hong F, Ma D, Wu K, Mina LA, Luiten RC, Liu Y, Yan H, Green AA. Precise and Programmable Detection of Mutations Using Ultraspecific Riboregulators. Cell 2020; 180:1018-1032.e16. [PMID: 32109416 PMCID: PMC7063572 DOI: 10.1016/j.cell.2020.02.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 01/01/2020] [Accepted: 02/04/2020] [Indexed: 12/18/2022]
Abstract
The ability to identify single-nucleotide mutations is critical for probing cell biology and for precise detection of disease. However, the small differences in hybridization energy provided by single-base changes makes identification of these mutations challenging in living cells and complex reaction environments. Here, we report a class of de novo-designed prokaryotic riboregulators that provide ultraspecific RNA detection capabilities in vivo and in cell-free transcription-translation reactions. These single-nucleotide-specific programmable riboregulators (SNIPRs) provide over 100-fold differences in gene expression in response to target RNAs differing by a single nucleotide in E. coli and resolve single epitranscriptomic marks in vitro. By exploiting the programmable SNIPR design, we implement an automated design algorithm to develop riboregulators for a range of mutations associated with cancer, drug resistance, and genetic disorders. Integrating SNIPRs with portable paper-based cell-free reactions enables convenient isothermal detection of cancer-associated mutations from clinical samples and identification of Zika strains through unambiguous colorimetric reactions.
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Affiliation(s)
- Fan Hong
- Biodesign Center for Molecular Design and Biomimetics at the Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Duo Ma
- Biodesign Center for Molecular Design and Biomimetics at the Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Kaiyue Wu
- Biodesign Center for Molecular Design and Biomimetics at the Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Lida A Mina
- Hematology-Oncology Department, Banner MD Anderson Cancer Center, Gilbert, AZ 85234, USA
| | - Rebecca C Luiten
- Genetics Department, Banner MD Anderson Cancer Center, Gilbert, AZ 85234, USA
| | - Yan Liu
- Biodesign Center for Molecular Design and Biomimetics at the Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Hao Yan
- Biodesign Center for Molecular Design and Biomimetics at the Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
| | - Alexander A Green
- Biodesign Center for Molecular Design and Biomimetics at the Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
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HIV-1 Reverse Transcriptase Promotes Tumor Growth and Metastasis Formation via ROS-Dependent Upregulation of Twist. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6016278. [PMID: 31885806 PMCID: PMC6915010 DOI: 10.1155/2019/6016278] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 11/01/2019] [Accepted: 11/05/2019] [Indexed: 12/15/2022]
Abstract
HIV-induced immune suppression results in the high prevalence of HIV/AIDS-associated malignancies including Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. HIV-infected people are also at an increased risk of “non-AIDS-defining” malignancies not directly linked to immune suppression but associated with viral infections. Their incidence is increasing despite successful antiretroviral therapy. The mechanism behind this phenomenon remains unclear. Here, we obtained daughter clones of murine mammary gland adenocarcinoma 4T1luc2 cells expressing consensus reverse transcriptase of HIV-1 subtype A FSU_A strain (RT_A) with and without primary mutations of drug resistance. In in vitro tests, mutations of resistance to nucleoside inhibitors K65R/M184V reduced the polymerase, and to nonnucleoside inhibitors K103N/G190S, the RNase H activities of RT_A. Expression of these RT_A variants in 4T1luc2 cells led to increased production of the reactive oxygen species (ROS), lipid peroxidation, enhanced cell motility in the wound healing assay, and upregulation of expression of Vimentin and Twist. These properties, particularly, the expression of Twist, correlated with the levels of expression RT_A and/or the production of ROS. When implanted into syngeneic BALB/C mice, 4T1luc2 cells expressing nonmutated RT_A demonstrated enhanced rate of tumor growth and increased metastatic activity, dependent on the level of expression of RT_A and Twist. No enhancement was observed for the clones expressing mutated RT_A variants. Plausible mechanisms are discussed involving differential interactions of mutated and nonmutated RTs with its cellular partners involved in the regulation of ROS. This study establishes links between the expression of HIV-1 RT, production of ROS, induction of EMT, and enhanced propagation of RT-expressing tumor cells. Such scenario can be proposed as one of the mechanisms of HIV-induced/enhanced carcinogenesis not associated with immune suppression.
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Abbas UL, Glaubius RL, Ding Y, Hood G. Drug resistance from preferred antiretroviral regimens for HIV infection in South Africa: A modeling study. PLoS One 2019; 14:e0218649. [PMID: 31269034 PMCID: PMC6609148 DOI: 10.1371/journal.pone.0218649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 06/06/2019] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Tenofovir-containing regimens comprise the preferred first-line antiretroviral therapy (ART) in many countries including South Africa, where utilization of second-line regimens is limited. Considerable HIV drug resistance has occurred among persons failing tenofovir-containing first-line ART. We evaluated drug resistance at the population level using mathematical modeling. SETTING Heterosexual HIV epidemic in KwaZulu-Natal, South Africa. METHODS We constructed a stochastic individual-based model and simulated scenarios of ART implementation, either CD4-based (threshold < 500 cells/mL) or Fast-track (81% coverage by 2020), with consideration of major drug-associated mutations (M184V, K65R and non-nucleoside reverse transcriptase inhibitor (NNRTI)). Using base case and uncertainty analyses, we assessed (majority) drug resistance levels. RESULTS By 2030, the median total resistance (proportion of HIV-infected persons with drug resistance) is predicted to reach 31.4% (interquartile range (IQR): 16.5%-50.2%) with CD4-based ART, decreasing to 14.5% (IQR: 7.7%-25.8%) with Fast-track implementation. In both scenarios, we find comparably high prevalence (~80%) of acquired NNRTI-associated, M184V and K65R mutations. Over 48% of individuals with acquired resistance harbor dual, 44% triple and 7% just single drug mutations. Drug-resistant HIV is predicted to comprise 40% (IQR: 27%-50%) of incident infections, while 70% of prevalent transmitted resistance is NNRTI-associated. At 2018, the projected total resistance is 15% (IQR: 7.5%-25%), with 18% (IQR: 13%-24%) of incident infections from transmitted drug-resistant HIV. CONCLUSIONS WHO-recommended preferred first-line ART could lead to substantial drug resistance. Effective surveillance of HIV drug resistance and utilization of second-line as well as alternative first-line regimens is crucial.
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Affiliation(s)
- Ume L. Abbas
- Department of Medicine, Section of Infectious Diseases and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Departments of Quantitative Health Sciences and Infectious Disease, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Robert L. Glaubius
- Departments of Quantitative Health Sciences and Infectious Disease, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Yajun Ding
- Department of Medicine, Section of Infectious Diseases and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Gregory Hood
- Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
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Twenty-Five Years of Lamivudine: Current and Future Use for the Treatment of HIV-1 Infection. J Acquir Immune Defic Syndr 2019; 78:125-135. [PMID: 29474268 PMCID: PMC5959256 DOI: 10.1097/qai.0000000000001660] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Supplemental Digital Content is Available in the Text. Innovation in medicine is a dynamic, complex, and continuous process that cannot be isolated to a single moment in time. Anniversaries offer opportunities to commemorate crucial discoveries of modern medicine, such as penicillin (1928), polio vaccination (inactivated, 1955; oral, 1961), the surface antigen of the hepatitis B virus (1967), monoclonal antibodies (1975), and the first HIV antiretroviral drugs (zidovudine, 1987). The advent of antiretroviral drugs has had a profound effect on the progress of the epidemiology of HIV infection, transforming a terminal, irreversible disease that caused a global health crisis into a treatable but chronic disease. This result has been driven by the success of antiretroviral drug combinations that include nucleoside reverse transcriptase inhibitors such as lamivudine. Lamivudine, an L-enantiomeric analog of cytosine, potently affects HIV replication by inhibiting viral reverse transcriptase enzymes at concentrations without toxicity against human polymerases. Although lamivudine was approved more than 2 decades ago, it remains a key component of first-line therapy for HIV because of its virological efficacy and ability to be partnered with other antiretroviral agents in traditional and novel combination therapies. The prominence of lamivudine in HIV therapy is highlighted by its incorporation in recent innovative treatment strategies, such as single-tablet regimens that address challenges associated with regimen complexity and treatment adherence and 2-drug regimens being developed to mitigate cumulative drug exposure and toxicities. This review summarizes how the pharmacologic and virologic properties of lamivudine have solidified its role in contemporary HIV therapy and continue to support its use in emerging therapies.
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Phillips AN, Venter F, Havlir D, Pozniak A, Kuritzkes D, Wensing A, Lundgren JD, De Luca A, Pillay D, Mellors J, Cambiano V, Bansi-Matharu L, Nakagawa F, Kalua T, Jahn A, Apollo T, Mugurungi O, Clayden P, Gupta RK, Barnabas R, Revill P, Cohn J, Bertagnolio S, Calmy A. Risks and benefits of dolutegravir-based antiretroviral drug regimens in sub-Saharan Africa: a modelling study. Lancet HIV 2019; 6:e116-e127. [PMID: 30503325 PMCID: PMC6361866 DOI: 10.1016/s2352-3018(18)30317-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/15/2018] [Accepted: 10/24/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND The integrase inhibitor dolutegravir could have a major role in future antiretroviral therapy (ART) regimens in sub-Saharan Africa because of its high potency and barrier to resistance, good tolerability, and low cost, but there is uncertainty over appropriate policies for use relating to the potential for drug resistance spread and a possible increased risk of neural tube defects in infants if used in women at the time of conception. We used an existing individual-based model of HIV transmission, progression, and the effect of ART with the aim of informing policy makers on approaches to the use of dolutegravir that are likely to lead to the highest population health gains. METHODS We used an existing individual-based model of HIV transmission and progression in adults, which takes into account the effects of drug resistance and differential drug potency in determining viral suppression and clinical outcomes to compare predicted outcomes of alternative ART regimen policies. We calculated disability adjusted life-years (DALYs) for each policy, assuming that a woman having a child with a neural tube defect incurs an extra DALY per year for the remainder of the time horizon and accounting for mother-to-child transmission. We used a 20 year time horizon, a 3% discount rate, and a cost-effectiveness threshold of US$500 per DALY averted. FINDINGS The greatest number of DALYs is predicted to be averted with use of a policy in which tenofovir, lamivudine, and dolutegravir is used in all people on ART, including switching to tenofovir, lamivudine, and dolutegravir in those currently on ART, regardless of current viral load suppression and intention to have (more) children. This result was consistent in several sensitivity analyses. We predict that this policy would be cost-saving. INTERPRETATION Using a standard DALY framework to compare health outcomes from a public health perspective, the benefits of transition to tenofovir, lamivudine, and dolutegravir for all substantially outweighed the risks. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
| | - Francois Venter
- Wits Reproductive Health and HIV Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Diane Havlir
- University of California, San Francisco, CA, USA
| | - Anton Pozniak
- Chelsea and Westminster Hospital, London, UK; London School of Hygiene & Tropical Medicine, London, UK
| | - Daniel Kuritzkes
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Annemarie Wensing
- Wits Reproductive Health and HIV Institute, University of the Witwatersrand, Johannesburg, South Africa; University Medical Center, Utrecht, Netherlands
| | - Jens D Lundgren
- Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Deenan Pillay
- Africa Health Research Institute, Mtubatuba, South Africa
| | | | | | | | | | | | - Andreas Jahn
- Ministry of Health, Lilongwe, Malawi; University of Washington, Seattle, WA, USA
| | | | | | | | | | | | | | - Jennifer Cohn
- Elizabeth Glaser Paediatric AIDS Foundation, Geneva, Switzerland
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Hunt GM, Dokubo EK, Takuva S, de Oliveira T, Ledwaba J, Dube N, Moodley P, Sabatier J, Deyde V, Morris L, Raizes E. Rates of virological suppression and drug resistance in adult HIV-1-positive patients attending primary healthcare facilities in KwaZulu-Natal, South Africa. J Antimicrob Chemother 2018; 72:3141-3148. [PMID: 28981637 DOI: 10.1093/jac/dkx252] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/28/2017] [Indexed: 11/14/2022] Open
Abstract
Background KwaZulu-Natal (KZN) Province in South Africa has the highest HIV disease burden in the country, with an estimated population prevalence of 24.7%. A pilot sentinel surveillance project was undertaken in KZN to classify the proportion of adult patients failing first-line ART and to describe the patterns of drug resistance mutations (DRMs) in patients with virological failure (VF). Methods Cross-sectional surveillance of acquired HIV drug resistance was conducted in 15 sentinel ART clinics between August and November 2013. Two population groups were surveyed: on ART for 12-15 months (Cohort A) or 24-36 months (Cohort B). Plasma specimens with viral load ≥1000 copies/mL were defined as VF and genotyped for DRMs. Results A total of 1299 adults were included in the analysis. The prevalence of VF was 4.0% (95% CI 1.8-8.8) among 540 adults in Cohort A and 7.7% (95% CI 4.4-13.0) of 759 adults in Cohort B. Treatment with efavirenz was more likely to suppress viral load in Cohort A (P = 0.005). Independent predictors of VF for Cohort B included male gender, advanced WHO stage at ART initiation and treatment with stavudine or zidovudine compared with tenofovir. DRMs were detected in 89% of 123 specimens with VF, including M184I/V, K103N/S, K65N/R, V106A/M and Y181C. Conclusions VF in adults in KZN was <8% up to 3 years post-ART initiation but was associated with a high frequency of DRMs. These data identify key groups for intensified adherence counselling and highlight the need to optimize first-line regimens to maintain viral suppression.
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Affiliation(s)
- Gillian M Hunt
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - E Kainne Dokubo
- Division of Global HIV and TB, US Centers for Disease Control and Prevention, Atlanta, USA
| | - Simbarashe Takuva
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Tulio de Oliveira
- KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
| | - Johanna Ledwaba
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Nomathemba Dube
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Pravi Moodley
- Department of Virology, National Health Laboratory Services/University of KwaZulu-Natal, South Africa
| | - Jennifer Sabatier
- Division of Global HIV and TB, US Centers for Disease Control and Prevention, Atlanta, USA
| | - Varough Deyde
- US Centers for Disease Control and Prevention, Pretoria, South Africa
| | - Lynn Morris
- Centre for HIV and STIs, National Institute for Communicable Diseases, Johannesburg, South Africa.,Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Elliot Raizes
- Division of Global HIV and TB, US Centers for Disease Control and Prevention, Atlanta, USA
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Xu HT, Hassounah SA, Colby-Germinario SP, Oliveira M, Fogarty C, Quan Y, Han Y, Golubkov O, Ibanescu I, Brenner B, Stranix BR, Wainberg MA. Purification of Zika virus RNA-dependent RNA polymerase and its use to identify small-molecule Zika inhibitors. J Antimicrob Chemother 2017; 72:727-734. [PMID: 28069884 DOI: 10.1093/jac/dkw514] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/01/2016] [Indexed: 12/21/2022] Open
Abstract
Background The viral RNA-dependent RNA polymerase (RdRp) enzymes of the Flaviviridae family are essential for viral replication and are logically important targets for development of antiviral therapeutic agents. Zika virus (ZIKV) is a rapidly re-emerging human pathogen for which no vaccine or antiviral agent is currently available. Methods To facilitate development of ZIKV RdRp inhibitors, we have established an RdRp assay using purified recombinant ZIKV NS5 polymerase. Results We have shown that both the hepatitis C virus (HCV) nucleoside inhibitor sofosbuvir triphosphate and a pyridoxine-derived non-nucleoside small-molecule inhibitor, DMB213, can act against ZIKV RdRp activity at IC 50 s of 7.3 and 5.2 μM, respectively, in RNA synthesis reactions catalysed by recombinant ZIKV NS5 polymerase. Cell-based assays confirmed the anti-ZIKV activity of sofosbuvir and DMB213 with 50% effective concentrations (EC 50 s) of 8.3 and 4.6 μM, respectively. Control studies showed that DMB213 did not inhibit recombinant HIV-1 reverse transcriptase and showed only very weak inhibition of HIV-1 integrase strand-transfer activity. The S604T substitution in motif B of the ZIKV RdRp, which corresponds to the S282T substitution in motif B of HCV RdRp, which confers resistance to nucleotide inhibitors, also conferred resistance to sofosbuvir triphosphate, but not to DMB213. Enzyme assays showed that DMB213 appears to be competitive with natural nucleoside triphosphate (NTP) substrates. Conclusions Recombinant ZIKV RdRp assays can be useful tools for the screening of both nucleos(t)ide compounds and non-nucleotide metal ion-chelating agents that interfere with ZIKV replication.
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Affiliation(s)
- Hong-Tao Xu
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Said A Hassounah
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Susan P Colby-Germinario
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Maureen Oliveira
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Clare Fogarty
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Yudong Quan
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Yingshan Han
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Olga Golubkov
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Ilinca Ibanescu
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | - Bluma Brenner
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada
| | | | - Mark A Wainberg
- Jewish General Hospital, McGill University AIDS Centre, Lady Davis Institute for Medical Research, Montreal, Quebec, Canada.,Department of Medicine, McGill University, Montreal, Quebec, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
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11
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Dinesha TR, Gomathi S, Boobalan J, Sivamalar S, Solomon SS, Pradeep A, Poongulali S, Solomon S, Balakrishnan P, Saravanan S. Genotypic HIV-1 Drug Resistance Among Patients Failing Tenofovir-Based First-Line HAART in South India. AIDS Res Hum Retroviruses 2016; 32:1234-1236. [PMID: 27334566 DOI: 10.1089/aid.2016.0110] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
According to 2013 WHO guidelines, tenofovir (TDF) is the preferred first-line regimen for adults and adolescents. A total of 167 HIV-1-infected patients attaining immunological failure after TDF-based first-line HAART were included in this study, RT region of HIV-1 pol gene was sequenced for them, IAS-USA 2014 list and Stanford HIV drug resistance database were used for mutation interpretation. REGA V3.0 was used for HIV subtyping. The predominant NRTI and NNRTI mutations observed were M184IV (59.9%), K65R (28.1%), and thymidine analogue mutations (TAMs, 29.3%) and K103NS (54.5%), V106AM (39.5%), and Y181CIV (19.8%), respectively. Mutational association shows, K65R was negatively associated with TAMs (OR 0.31, p .008), M184V (OR 0.14, p .57), and K70E (OR 0.29, p .02). Genotypically predicted level of drug resistance based on mutation pattern shows 88% can be opted for azidothymidine (AZT) and still 65% can be opted for TDF. Considering the nature of K65R mutation in increasing susceptibility to AZT and its low prevalence, we conclude that in most patients failing TDF-based first-line therapy, AZT can be considered for second-line therapy followed by TDF itself.
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Affiliation(s)
- Thongadi Ramesh Dinesha
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Selvamurthi Gomathi
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Jayaseelan Boobalan
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Sathasivam Sivamalar
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Sunil S Solomon
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
- 2 Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Ambrose Pradeep
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Selvamuthu Poongulali
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Suniti Solomon
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Pachamuthu Balakrishnan
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
| | - Shanmugam Saravanan
- 1 Y.R. Gaitonde Centre for AIDS Research and Education, Voluntary Health Services , Taramani, Chennai, India
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12
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Abstract
PURPOSE OF REVIEW To review current data on HIV-1 resistance arising from the use of fixed dose combination tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for preexposure prophylaxis (PrEP) to prevent HIV-1 infection. RECENT FINDINGS Resistance to tenofovir (TNV) or FTC is infrequently selected by TDF/FTC PrEP if started before HIV-1 infection has occurred, but is much more common when inadvertently started during undiagnosed acute infection. Mathematical modeling predicts that the number of HIV-1 infections averted by the use of PrEP far exceeds the increase in drug-resistant infections that could occur from PrEP. Studies in macaques show that TNV-resistant virus but not FTC-resistant virus can cause breakthrough infection despite TDF/FTC PrEP. FTC resistance with M184 V/I occurs more frequently than TFV resistance with K65R in seroconverters from clinical trials of TDF/FTC PrEP. SUMMARY The benefit of preventing HIV-1 infections with TDF/FTC PrEP far outweighs the risk of drug-resistant infection, provided PrEP is not started in persons with undiagnosed HIV-1 infection. We should respect but not fear HIV-1 resistance from TDF/FTC PrEP and recognize that most TNV or FTC resistance will arise from its use for antiretroviral therapy (ART). Preventing ART failure or detecting it early is most important for preventing the spread of HIV-1 resistance to TDF/FTC and preserving its effectiveness for both PrEP and ART.
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13
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Pham HT, Mesplède T, Wainberg MA. Effect on HIV-1 viral replication capacity of DTG-resistance mutations in NRTI/NNRTI resistant viruses. Retrovirology 2016; 13:31. [PMID: 27130466 PMCID: PMC4851780 DOI: 10.1186/s12977-016-0265-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/19/2016] [Indexed: 12/15/2022] Open
Abstract
Background Recommended regimens for HIV-positive individuals include the co-administration of dolutegravir (DTG) with two reverse transcriptase inhibitors (RTIs). Although rare, emerging resistance against DTG is often associated with the R263K substitution in integrase. In-vitro-selected R263K was associated with impaired viral replication capacity, DNA integration, and integrase strand-transfer activity, especially when accompanied by the secondary mutation H51Y. Given the reduced fitness of RTI-resistant viruses, we investigated potential impacts on viral replication of combining R263K and H51Y/R263K with major RTI-resistance substitutions including K65R, L74V, K103N, E138K, and M184I/V. Results We combined the R263K or H51Y/R263K with RTI-resistance mutations into the proviral plasmid pNL4.3 and measured the resulting viral infectiousness, replication capacity, and ability to integrate viral DNA into host cells. Infectiousness was determined by luciferase assay in TZM-bl cells. Replicative capacity was monitored over 7 days and viral DNA integration was studied by real-time Alu-qPCR in PM1 cells. We found that viral infectiousness, replication capacities and integration levels were greatly reduced in triple mutants, i.e. H51Y/R263K plus a RT mutation, and moderately reduced in double mutants, i.e. R263K plus a RT mutation, compared to wild-type and single RT-mutant viruses. Conclusions Our findings help to explain the absence of RTI mutations in individuals who experienced DTG-treatment failure.
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Affiliation(s)
- Hanh T Pham
- McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Côte-Ste-Catherine, Montreal, QC, H3T 1E2, Canada.,Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Thibault Mesplède
- McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Côte-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
| | - Mark A Wainberg
- McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Côte-Ste-Catherine, Montreal, QC, H3T 1E2, Canada. .,Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, QC, Canada. .,Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada.
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14
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Inzaule SC, Weidle PJ, Yang C, Ndiege K, Hamers RL, Rinke de Wit TF, Thomas T, Zeh C. Prevalence and dynamics of the K65R drug resistance mutation in HIV-1-infected infants exposed to maternal therapy with lamivudine, zidovudine and either nevirapine or nelfinavir in breast milk. J Antimicrob Chemother 2016; 71:1619-26. [PMID: 26953333 DOI: 10.1093/jac/dkw039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/29/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND K65R is a relatively rare drug resistance mutation (DRM) selected by the NRTIs tenofovir, didanosine, abacavir and stavudine and confers cross-resistance to all NRTIs except zidovudine. Selection by other NRTIs is uncommon. OBJECTIVES In this study we investigated the frequency of emergence of the K65R mutation and factors associated with it in HIV-1-infected infants exposed to low doses of maternal lamivudine, zidovudine and either nevirapine or nelfinavir ingested through breast milk, using specimens collected from the Kisumu Breastfeeding Study. METHODS Plasma specimens with viral load ≥1000 copies/mL collected from HIV-infected infants at 0-1, 2, 6, 14, 24 and 36 weeks of age and maternal samples at delivery were tested for HIV drug resistance using Sanger sequencing of the polymerase gene. Factors associated with K65R emergence were assessed using Fisher's exact test and the Wilcoxon rank-sum test. RESULTS K65R was detected in samples from 6 of the 24 infants (25%) who acquired HIV-1 infection by the age of 6 months. K65R emerged in half of the infants by 6 weeks and in the rest by 14 weeks of age. None of the mothers at delivery or the infants with a positive genotype at first time of positivity had the K65R mutation. Infants with K65R had low baseline CD4 cell counts (P = 0.014), were more likely to have DRMs earlier (≤6 weeks versus ≥14 weeks, P = 0.007) and were more likely to have multiclass drug resistance (P = 0.035). M184V was the most common mutation associated with K65R emergence. K65R had reverted by 3 months after cessation of breastfeeding. CONCLUSIONS A high rate of K65R emergence may suggest that ingesting low doses of lamivudine via breast milk could select for this mutation. The presence of this mutation may have a negative impact on future responses to NRTI-based ART. More in vitro studies are, however, needed to establish the molecular mechanism for this selection.
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Affiliation(s)
- Seth C Inzaule
- Kenya Medical Research Institute, Kisumu, Kenya Department of Global Health, Academic Medical Center of the University of Amsterdam, and Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - Paul J Weidle
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Chunfu Yang
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Raph L Hamers
- Department of Global Health, Academic Medical Center of the University of Amsterdam, and Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - Tobias F Rinke de Wit
- Department of Global Health, Academic Medical Center of the University of Amsterdam, and Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - Timothy Thomas
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Clement Zeh
- Centers for Disease Control and Prevention, Kisumu, Kenya
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15
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Lloyd SB, Lichtfuss M, Amarasena TH, Alcantara S, De Rose R, Tachedjian G, Alinejad-Rokny H, Venturi V, Davenport MP, Winnall WR, Kent SJ. High fidelity simian immunodeficiency virus reverse transcriptase mutants have impaired replication in vitro and in vivo. Virology 2016; 492:1-10. [PMID: 26896929 DOI: 10.1016/j.virol.2016.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/09/2016] [Accepted: 02/11/2016] [Indexed: 11/15/2022]
Abstract
The low fidelity of HIV replication facilitates immune and drug escape. Some reverse transcriptase (RT) inhibitor drug-resistance mutations increase RT fidelity in biochemical assays but their effect during viral replication is unclear. We investigated the effect of RT mutations K65R, Q151N and V148I on SIV replication and fidelity in vitro, along with SIV replication in pigtailed macaques. SIVmac239-K65R and SIVmac239-V148I viruses had reduced replication capacity compared to wild-type SIVmac239. Direct virus competition assays demonstrated a rank order of wild-type>K65R>V148I mutants in terms of viral fitness. In single round in vitro-replication assays, SIVmac239-K65R demonstrated significantly higher fidelity than wild-type, and rapidly reverted to wild-type following infection of macaques. In contrast, SIVmac239-Q151N was replication incompetent in vitro and in pigtailed macaques. Thus, we showed that RT mutants, and specifically the common K65R drug-resistance mutation, had impaired replication capacity and higher fidelity. These results have implications for the pathogenesis of drug-resistant HIV.
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Affiliation(s)
- Sarah B Lloyd
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Marit Lichtfuss
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Thakshila H Amarasena
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Sheilajen Alcantara
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Robert De Rose
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Gilda Tachedjian
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia; Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia; Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia
| | | | - Vanessa Venturi
- Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Miles P Davenport
- Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Wendy R Winnall
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Stephen J Kent
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia; Melbourne Sexual Health Centre and Department of Infectious Diseases, Alfred Health, Central Clinical School, Monash University, Melbourne, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of Melbourne, Parkville, Australia.
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16
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Identification of a Pyridoxine-Derived Small-Molecule Inhibitor Targeting Dengue Virus RNA-Dependent RNA Polymerase. Antimicrob Agents Chemother 2015; 60:600-8. [PMID: 26574011 DOI: 10.1128/aac.02203-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/10/2015] [Indexed: 01/14/2023] Open
Abstract
The viral RNA-dependent RNA polymerase (RdRp) activity of the dengue virus (DENV) NS5 protein is an attractive target for drug design. Here, we report the identification of a novel class of inhibitor (i.e., an active-site metal ion chelator) that acts against DENV RdRp activity. DENV RdRp utilizes a two-metal-ion mechanism of catalysis; therefore, we constructed a small library of compounds, through mechanism-based drug design, aimed at chelating divalent metal ions in the catalytic site of DENV RdRp. We now describe a pyridoxine-derived small-molecule inhibitor that targets DENV RdRp and show that 5-benzenesulfonylmethyl-3-hydroxy-4-hydroxymethyl-pyridine-2-carboxylic acid hydroxyamide (termed DMB220) inhibited the RdRp activity of DENV serotypes 1 to 4 at low micromolar 50% inhibitory concentrations (IC50s of 5 to 6.7 μM) in an enzymatic assay. The antiviral activity of DMB220 against DENV infection was also verified in a cell-based assay and showed a 50% effective concentration (EC50) of <3 μM. Enzyme assays proved that DMB220 was competitive with nucleotide incorporation. DMB220 did not inhibit the enzymatic activity of recombinant HIV-1 reverse transcriptase and showed only weak inhibition of HIV-1 integrase strand transfer activity, indicating high specificity for DENV RdRp. S600T substitution in the DENV RdRp, which was previously shown to confer resistance to nucleoside analogue inhibitors (NI), conferred 3-fold hypersusceptibility to DMB220, and enzymatic analyses showed that this hypersusceptibility may arise from the decreased binding/incorporation efficiency of the natural NTP substrate without significantly impacting inhibitor binding. Thus, metal ion chelation at the active site of DENV RdRp represents a viable anti-DENV strategy, and DMB220 is the first of a new class of DENV inhibitor.
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Subtype-specific analysis of the K65R substitution in HIV-1 that confers hypersusceptibility to a novel nucleotide-competing reverse transcriptase inhibitor. Antimicrob Agents Chemother 2015; 59:3189-96. [PMID: 25779585 DOI: 10.1128/aac.00315-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/11/2015] [Indexed: 12/20/2022] Open
Abstract
Compound A is a novel nucleotide-competing HIV-1 reverse transcriptase (RT) inhibitor (NcRTI) that selects for a unique W153L substitution that confers hypersusceptibility to tenofovir, while the K65R substitution in RT confers resistance against tenofovir and enhances susceptibility to NcRTIs. Although the K65R substitution is more common in subtype C viruses, the impact of subtype variability on NcRTI susceptibility has not been studied. In the present study, we performed experiments with compound A by using purified recombinant RT enzymes and viruses of subtypes B and C and circulating recombinant form CRF_A/G. We confirmed the hypersusceptibility of K65R substitution-containing RTs to compound A for subtype C, CRF_A/G, and subtype B. Steady-state kinetic analysis showed that K65R RTs enhanced the susceptibility to compound A by increasing binding of the inhibitor to the nucleotide binding site of RT in a subtype-independent manner, without significantly discriminating against the natural nucleotide substrate. These data highlight the potential utility of NcRTIs, such as compound A, for treatment of infections with K65R substitution-containing viruses, regardless of HIV-1 subtype.
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18
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The lysine 65 residue in HIV-1 reverse transcriptase function and in nucleoside analog drug resistance. Viruses 2014; 6:4080-94. [PMID: 25341667 PMCID: PMC4213578 DOI: 10.3390/v6104080] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 10/19/2014] [Accepted: 10/20/2014] [Indexed: 12/04/2022] Open
Abstract
Mutations in HIV-1 reverse transcriptase (RT) that confer nucleoside analog RT inhibitor resistance have highlighted the functional importance of several active site residues (M184, Q151 and K65) in RT catalytic function. Of these, K65 residue is notable due to its pivotal position in the dNTP-binding pocket, its involvement in nucleoside analog resistance and polymerase fidelity. This review focuses on K65 residue and summarizes a substantial body of biochemical and structural studies of its role in RT function and the functional consequences of the K65R mutation.
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19
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Effects of the W153L substitution in HIV reverse transcriptase on viral replication and drug resistance to multiple categories of reverse transcriptase inhibitors. Antimicrob Agents Chemother 2014; 58:4515-26. [PMID: 24867966 DOI: 10.1128/aac.02729-14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A W153L substitution in HIV-1 reverse transcriptase (RT) was recently identified by selection with a novel nucleotide-competing RT inhibitor (NcRTI) termed compound A that is a member of the benzo[4,5]furo[3,2,d]pyrimidin-2-one NcRTI family of drugs. To investigate the impact of W153L, alone or in combination with the clinically relevant RT resistance substitutions K65R (change of Lys to Arg at position 65), M184I, K101E, K103N, E138K, and Y181C, on HIV-1 phenotypic susceptibility, viral replication, and RT enzymatic function, we generated recombinant RT enzymes and viruses containing each of these substitutions or various combinations of them. We found that W153L-containing viruses were impaired in viral replicative capacity and were hypersusceptible to tenofovir (TFV) while retaining susceptibility to most nonnucleoside RT inhibitors. The nucleoside 3TC retained potency against W153L-containing viruses but not when the M184I substitution was also present. W153L was also able to reverse the effects of the K65R substitution on resistance to TFV, and K65R conferred hypersusceptibility to compound A. Biochemical assays demonstrated that W153L alone or in combination with K65R, M184I, K101E, K103N, E138K, and Y181C impaired enzyme processivity and polymerization efficiency but did not diminish RNase H activity, providing mechanistic insights into the low replicative fitness associated with these substitutions. We show that the mechanism of the TFV hypersusceptibility conferred by W153L is mainly due to increased efficiency of TFV-diphosphate incorporation. These results demonstrate that compound A and/or derivatives thereof have the potential to be important antiretroviral agents that may be combined with tenofovir to achieve synergistic results.
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Averted HIV infections due to expanded antiretroviral treatment eligibility offsets risk of transmitted drug resistance: a modeling study. AIDS 2014; 28:73-83. [PMID: 23921620 DOI: 10.1097/01.aids.0000433239.01611.52] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Earlier antiretroviral therapy initiation can reduce the incidence of HIV-1. This benefit can be offset by increased transmitted drug resistance (TDR). We compared the preventive benefits of reducing incident infections with the potential TDR increase in East Africa. METHODS A mathematical model was constructed to represent Kampala, Uganda, and Mombasa, Kenya. We predicted the effect of initiating treatment at different immunological thresholds (<350, <500 CD4 cells/μl) on infections averted and mutation-specific TDR prevalence over 10 years compared to initiating treatment at CD4 cell count below 200 cells/μl. RESULTS When initiating treatment at CD4 cell count below 350 cells/μl, we predict 18 [interquartile range (IQR) 11-31] and 46 (IQR 30-83) infections averted for each additional case of TDR in Kampala and Mombasa, respectively, and 22 (IQR 17-35) and 32 (IQR 21-57) infections averted when initiating at below 500. TDR is predicted to increase most strongly when initiating treatment at CD4 cell count below 500 cells/μl, from 8.3% (IQR 7.7-9.0%) and 12.3% (IQR 11.7-13.1%) in 2012 to 19.0% (IQR 16.5-21.8%) and 19.2% (IQR 17.1-21.5%) in 10 years in Kampala and Mombasa, respectively. The TDR epidemic at all immunological thresholds was comprised mainly of resistance to non-nucleoside reverse transcriptase inhibitors. When 80-100% of individuals with virological failure are timely switched to second-line therapy, TDR is predicted to decline irrespective of treatment initiation threshold. CONCLUSION Averted HIV infections due to the expansion of antiretroviral treatment eligibility offset the risk of transmitted drug resistance, as defined by more infections averted than TDR gained. The effectiveness of first-line non-nucleoside reverse transcriptase inhibitor-based therapy can be preserved by improving switching practices to second-line therapy.
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21
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Abstract
The notoriously low fidelity of HIV-1 replication is largely responsible for the virus's rapid mutation rate, facilitating escape from immune or drug control. The error-prone activity of the viral reverse transcriptase (RT) is predicted to be the most influential mechanism for generating mutations. The low fidelity of RT has been successfully exploited by nucleoside and nucleotide analogue reverse transcriptase inhibitors (NRTIs) that halt viral replication upon incorporation. Consequently, drug-resistant strains have arisen in which the viral RT has an increased fidelity of replication, thus reducing analogue incorporation. Higher fidelity, however, impacts on viral fitness. The appearance of compensatory mutations in combination with higher fidelity NRTI resistance mutations and the subsequent reversion of NRTI-resistant mutations upon cessation of antiretroviral treatment lend support to the notion that higher fidelity exacts a fitness cost. Potential mechanisms for reduced viral fitness are a smaller pool of mutant strains available to respond to immune or drug pressure, slower rates of replication, and a limitation to the dNTP tropism of the virus. Unraveling the relationship between replication fidelity and fitness should lead to a greater understanding of the evolution and control of HIV.
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Affiliation(s)
- Sarah B. Lloyd
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, VIC, Australia
| | - Stephen J. Kent
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, VIC, Australia
| | - Wendy R. Winnall
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, VIC, Australia
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22
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Heredia A, Davis CE, Reitz MS, Le NM, Wainberg MA, Foulke JS, Wang LX, Redfield RR. Targeting of the purine biosynthesis host cell pathway enhances the activity of tenofovir against sensitive and drug-resistant HIV-1. J Infect Dis 2013; 208:2085-94. [PMID: 23922365 PMCID: PMC3836462 DOI: 10.1093/infdis/jit395] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 06/11/2013] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Targeting host-cell pathways to increase the potency of nucleoside/nucleotide analog reverse transcriptase inhibitors (NRTIs) is an important strategy for clinical investigation. Resveratrol is a natural product that inhibits cellular ribonucleotide reductase, prolonging the S phase of the cell cycle and preferentially lowering dATP levels. METHODS We performed in vitro evaluation of resveratrol on the antiviral activity of adenosine analog tenofovir (TFV) against sensitive and drug-resistant human immunodeficiency virus type 1 (HIV-1), from subtypes B and C, in primary cells. RESULTS Resveratrol enhanced the antiviral activity of TFV by up to 10-fold and restored susceptibility of TFV-resistant viruses. Resveratrol prevented wild-type HIV-1 from developing phenotypic resistance to TFV. Notably, resveratrol enhanced TFV activity against sensitive and resistant HIV-1 from both subtypes B and C. CONCLUSIONS Prolonged wide-scale use of thymidine analogs in the setting of viral failure has limited the efficacy of second-line NRTI-based regimens in Africa. Moreover, the extensive use of ddI and d4T has led to high frequencies of the K65R mutation, further compromising TFV efficacy. In light of increasing resistance to commonly used NRTIs in global HIV treatment programs, targeting nucleoside biosynthesis with resveratrol, or derivatives with improved bioavailabilities, is a potential strategy to maintain, enhance, and restore susceptibility of commonly used NRTIs.
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Affiliation(s)
- Alonso Heredia
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Charles E. Davis
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Marvin S. Reitz
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Nhut M. Le
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mark A. Wainberg
- McGill University AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
| | - James S. Foulke
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Lai-Xi Wang
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert R. Redfield
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
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23
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Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) remain a critical component of therapy for HIV-infected patients. The drugs are effective, relatively inexpensive and an important component of antiretroviral therapy (ART), particularly in areas where the introduction of effective therapy has been delayed. They are an essential part of initial therapy for HIV and for prevention of mother-to-child transmission; however, toxicities and resistance may limit their use. The role for pre-exposure prophylaxis (PrEP) to reduce sexual transmission of HIV is still undefined, but this use may have a significant impact on NRTI resistance worldwide, most particularly in areas where subtype C predominates. With increasing prevalence of resistant HIV, the approval of new agents that are effective against resistant virus, and those that use novel cellular targets, are essential. Large studies are now in progress examining the safety and efficacy of NRTI-sparing regimens, but results are not currently available. NRTIs may lose relevance in the not distant future unless steps are put in place to reduce the development and spread of NRTI-resistant viruses, and new NRTIs with minimal toxicity are developed that have a novel resistance profile. This article describes the principal NRTIs, their mechanism of action, and resistance and selected toxicities of the class and of the individual drugs.
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Affiliation(s)
- Randall Tressler
- HJF, Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MA 20892, USA
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Intersubtype differences in the effect of a rare p24 gag mutation on HIV-1 replicative fitness. J Virol 2012; 86:13423-33. [PMID: 23015721 DOI: 10.1128/jvi.02171-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Certain immune-driven mutations in HIV-1, such as those arising in p24(Gag), decrease viral replicative capacity. However, the intersubtype differences in the replicative consequences of such mutations have not been explored. In HIV-1 subtype B, the p24(Gag) M250I mutation is a rare variant (0.6%) that is enriched among elite controllers (7.2%) (P = 0.0005) and appears to be a rare escape variant selected by HLA-B58 supertype alleles (P < 0.01). In contrast, in subtype C, it is a relatively common minor polymorphic variant (10 to 15%) whose appearance is not associated with a particular HLA allele. Using site-directed mutant viruses, we demonstrate that M250I reduces in vitro viral replicative capacity in both subtype B and subtype C sequences. However, whereas in subtype C downstream compensatory mutations at p24(Gag) codons 252 and 260 reduce the adverse effects of M250I, fitness costs in subtype B appear difficult to restore. Indeed, patient-derived subtype B sequences harboring M250I exhibited in vitro replicative defects, while those from subtype C did not. The structural implications of M250I were predicted by protein modeling to be greater in subtype B versus C, providing a potential explanation for its lower frequency and enhanced replicative defects in subtype B. In addition to accounting for genetic differences between HIV-1 subtypes, the design of cytotoxic-T-lymphocyte-based vaccines may need to account for differential effects of host-driven viral evolution on viral fitness.
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The Impact of HIV Genetic Polymorphisms and Subtype Differences on the Occurrence of Resistance to Antiretroviral Drugs. Mol Biol Int 2012; 2012:256982. [PMID: 22792462 PMCID: PMC3390109 DOI: 10.1155/2012/256982] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 04/12/2012] [Indexed: 12/20/2022] Open
Abstract
The vast majority of reports on drug resistance deal with subtype B infections in developed countries, and this is largely due to historical delays in access to antiretroviral therapy (ART) on a worldwide basis. This notwithstanding the concept that naturally occurring polymorphisms among different non-B subtypes can affect HIV-1 susceptibility to antiretroviral drugs (ARVs) is supported by both enzymatic and virological data. These findings suggest that such polymorphisms can affect both the magnitude of resistance conferred by some major mutations as well as the propensity to acquire certain resistance mutations, even though such differences are sometimes difficult to demonstrate in phenotypic assays. It is mandatory that tools are optimized to assure accurate measurements of drug susceptibility in non-B subtypes and to recognize that each subtype may have a distinct resistance profile and that differences in resistance pathways may also impact on cross-resistance and the choice of regimens to be used in second-line therapy. Although responsiveness to first-line therapy should not theoretically be affected by considerations of viral subtype and drug resistance, well-designed long-term longitudinal studies involving patients infected by viruses of different subtypes should be carried out.
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Affiliation(s)
- Mark A Wainberg
- McGill University AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal, QC H3T 1E2, Canada.
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Coutsinos D, Invernizzi CF, Moisi D, Oliveira M, Martinez-Cajas JL, Brenner BG, Wainberg MA. A template-dependent dislocation mechanism potentiates K65R reverse transcriptase mutation development in subtype C variants of HIV-1. PLoS One 2011; 6:e20208. [PMID: 21655292 PMCID: PMC3105016 DOI: 10.1371/journal.pone.0020208] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 04/15/2011] [Indexed: 01/11/2023] Open
Abstract
Numerous studies have suggested that the K65R reverse transcriptase (RT) mutation develops more readily in subtype C than subtype B HIV-1. We recently showed that this discrepancy lies partly in the subtype C template coding sequence that predisposes RT to pause at the site of K65R mutagenesis. However, the mechanism underlying this observation and the elevated rates of K65R development remained unknown. Here, we report that DNA synthesis performed with subtype C templates consistently produced more K65R-containing transcripts than subtype B templates, regardless of the subtype-origin of the RT enzymes employed. These findings confirm that the mechanism involved is template-specific and RT-independent. In addition, a pattern of DNA synthesis characteristic of site-specific primer/template slippage and dislocation was only observed with the subtype C sequence. Analysis of RNA secondary structure suggested that the latter was unlikely to impact on K65R development between subtypes and that Streisinger strand slippage during DNA synthesis at the homopolymeric nucleotide stretch of the subtype C K65 region might occur, resulting in misalignment of the primer and template. Consequently, slippage would lead to a deletion of the middle adenine of codon K65 and the production of a -1 frameshift mutation, which upon dislocation and realignment of the primer and template, would lead to development of the K65R mutation. These findings provide additional mechanistic evidence for the facilitated development of the K65R mutation in subtype C HIV-1.
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Affiliation(s)
- Dimitrios Coutsinos
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
- Departments of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
- Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Cédric F. Invernizzi
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
- Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Daniela Moisi
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
| | - Maureen Oliveira
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
| | - Jorge L. Martinez-Cajas
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
- Department of Medicine, Infectious Diseases, Queen's University, Kingston, Ontario, Canada
| | - Bluma G. Brenner
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
- Departments of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
- Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Mark A. Wainberg
- McGill University AIDS Center, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada
- Departments of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
- Department of Medicine, McGill University, Montréal, Québec, Canada
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Chunduri H, Crumpacker C, Sharma PL. Reverse transcriptase mutation K65N confers a decreased replication capacity to HIV-1 in comparison to K65R due to a decreased RT processivity. Virology 2011; 414:34-41. [PMID: 21459401 DOI: 10.1016/j.virol.2011.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 03/04/2011] [Accepted: 03/09/2011] [Indexed: 11/30/2022]
Abstract
In addition to K65R, the other mutation observed at HIV-1 RT codon 65 is K65N. While K65N appears to have a phenotypic effect similar to K65R, it is less frequent during clinical trials. We compared the relative impact of K→N with respect to K→R change on viral replication capacity (RC). Mutant viruses were created and replication kinetics assays were performed in PBM cells. Analysis of RCs revealed a significant loss in replication (p=0.004) for viruses containing K65N mutation in comparison to those with K65R mutation. RT processivity assays showed a significant decrease in the processivity of K65N RT in comparison to K65R RT. We demonstrated that the significant decrease in RC of K65N viruses is related to the impaired RT processivity of K65N RT in comparison to K65R, and that the selection of the K65R mutation may be favored in clinical use of antiretroviral drugs compared to K65N.
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Chunduri H, Rimland D, Nurpeisov V, Crumpacker CS, Sharma PL. A Leu to Ile but not Leu to Val change at HIV-1 reverse transcriptase codon 74 in the background of K65R mutation leads to an increased processivity of K65R+L74I enzyme and a replication competent virus. Virol J 2011; 8:33. [PMID: 21255423 PMCID: PMC3038945 DOI: 10.1186/1743-422x-8-33] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 01/21/2011] [Indexed: 12/30/2022] Open
Abstract
Background The major hurdle in the treatment of Human Immunodeficiency virus type 1 (HIV-1) includes the development of drug resistance-associated mutations in the target regions of the virus. Since reverse transcriptase (RT) is essential for HIV-1 replication, several nucleoside analogues have been developed to target RT of the virus. Clinical studies have shown that mutations at RT codon 65 and 74 which are located in β3-β4 linkage group of finger sub-domain of RT are selected during treatment with several RT inhibitors, including didanosine, deoxycytidine, abacavir and tenofovir. Interestingly, the co-selection of K65R and L74V is rare in clinical settings. We have previously shown that K65R and L74V are incompatible and a R→K reversion occurs at codon 65 during replication of the virus. Analysis of the HIV resistance database has revealed that similar to K65R+L74V, the double mutant K65R+L74I is also rare. We sought to compare the impact of L→V versus L→I change at codon 74 in the background of K65R mutation, on the replication of doubly mutant viruses. Methods Proviral clones containing K65R, L74V, L74I, K65R+L74V and K65R+L74I RT mutations were created in pNL4-3 backbone and viruses were produced in 293T cells. Replication efficiencies of all the viruses were compared in peripheral blood mononuclear (PBM) cells in the absence of selection pressure. Replication capacity (RC) of mutant viruses in relation to wild type was calculated on the basis of antigen p24 production and RT activity, and paired analysis by student t-test was performed among RCs of doubly mutant viruses. Reversion at RT codons 65 and 74 was monitored during replication in PBM cells. In vitro processivity of mutant RTs was measured to analyze the impact of amino acid changes at RT codon 74. Results Replication kinetics plot showed that all of the mutant viruses were attenuated as compared to wild type (WT) virus. Although attenuated in comparison to WT virus and single point mutants K65R, L74V and L74I; the double mutant K65R+L74I replicated efficiently in comparison to K65R+L74V mutant. The increased replication capacity of K65R+L74I viruses in comparison to K65R+L74V viruses was significant at multiplicity of infection 0.01 (p = 0.0004). Direct sequencing and sequencing after population cloning showed a more pronounced reversion at codon 65 in viruses containing K65R+L74V mutations in comparison to viruses with K65R+L74I mutations. In vitro processivity assays showed increased processivity of RT containing K65R+L74I in comparison to K65R+L74V RT. Conclusions The improved replication kinetics of K65R+L74I virus in comparison to K65R+L74V viruses was due to an increase in the processivity of RT containing K65R+L74I mutations. These observations support the rationale behind structural functional analysis to understand the interactions among unique RT mutations that may emerge during the treatment with specific drug regimens.
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Affiliation(s)
- Himabindu Chunduri
- Medical Research 151MV, Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, Georgia 30033, USA.
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30
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Chaplin B, Eisen G, Idoko J, Onwujekwe D, Idigbe E, Adewole I, Gashau W, Meloni S, Sarr A, Sankalé J, Ekong E, Murphy R, Kanki P. Impact of HIV type 1 subtype on drug resistance mutations in Nigerian patients failing first-line therapy. AIDS Res Hum Retroviruses 2011; 27:71-80. [PMID: 20964479 DOI: 10.1089/aid.2010.0050] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A diverse array of non-subtype B HIV-1 viruses circulates in Africa and dominates the global pandemic. It is important to understand how drug resistance mutations in non-B subtypes may develop differently from the patterns described in subtype B. HIV-1 reverse transcriptase and protease sequences from 338 patients with treatment failure to first-line ART regimens were evaluated. Multivariate logistic regression was used to examine the effect of subtype on each mutation controlling for regimen, time on therapy, and total mutations. The distribution of HIV-1 subtypes included CRF02_AG (45.0%), G (37.9%), CRF06_cpx (4.4%), A (3.6%), and other subtypes or recombinant sequences (9.2%). The most common NRTI mutations were M184V (89.1%) and thymidine analog mutations (TAMs). The most common NNRTI mutations were Y181C (49.7%), K103N (36.4%), G190A (26.3%), and A98G (19.5%). Multivariate analysis showed that CRF02_AG was less likely to have the M41L mutation compared to other subtypes [adjusted odds ratio (AOR) = 0.35; p = 0.022]. Subtype A patients showed a 42.5-fold increased risk (AOR = 42.5, p = 0.001) for the L210W mutation. Among NNRTI mutations, subtype G patients had an increased risk for A98G (AOR = 2.40, p = 0.036) and V106I (AOR = 6.15, p = 0.010), whereas subtype CRF02_AG patients had an increased risk for V90I (AOR = 3.16; p = 0.003) and a decreased risk for A98G (AOR = 0.48, p = 0.019). Five RT mutations were found to vary significantly between different non-B West African subtypes. Further study to understand the clinical impact of subtype-specific diversity on drug resistance will be critically important to the continued success of ART scale-up in resource-limited settings.
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Affiliation(s)
- B. Chaplin
- Harvard School of Public Health, Boston, Massachusetts
| | - G. Eisen
- Harvard School of Public Health, Boston, Massachusetts
| | - J. Idoko
- Jos University Teaching Hospital, Plateau State, Nigeria
| | - D. Onwujekwe
- National Institute of Medical Research, Lagos, Nigeria
| | - E. Idigbe
- National Institute of Medical Research, Lagos, Nigeria
| | - I. Adewole
- University College Hospital, Ibadan, Nigeria
| | - W. Gashau
- University Maiduguri Teaching Hospital, Maiduguri, Nigeria
| | - S. Meloni
- Harvard School of Public Health, Boston, Massachusetts
| | - A.D. Sarr
- Harvard School of Public Health, Boston, Massachusetts
| | - J.L. Sankalé
- Harvard School of Public Health, Boston, Massachusetts
| | - E. Ekong
- Harvard School of Public Health, Boston, Massachusetts
| | | | - P. Kanki
- Harvard School of Public Health, Boston, Massachusetts
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Wainberg MA, Brenner BG. Role of HIV Subtype Diversity in the Development of Resistance to Antiviral Drugs. Viruses 2010; 2:2493-508. [PMID: 21994627 PMCID: PMC3185584 DOI: 10.3390/v2112493] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 10/26/2010] [Accepted: 10/28/2010] [Indexed: 12/13/2022] Open
Abstract
Despite the fact that over 90% of HIV-1 infected people worldwide harbor non-subtype B variants of HIV-1, knowledge of resistance mutations in non-B HIV-1 and their clinical relevance is limited. Due to historical delays in access to antiretroviral therapy (ART) on a worldwide basis, the vast majority of reports on drug resistance deal with subtype B infections in developed countries. However, both enzymatic and virological data support the concept that naturally occurring polymorphisms among different nonB subtypes can affect HIV-1 susceptibility to antiretroviral drugs (ARVs), the magnitude of resistance conferred by major mutations, and the propensity to acquire some resistance mutations. Tools need to be optimized to assure accurate measurements of drug susceptibility of non-B subtypes. Furthermore, there is a need to recognize that each subtype may have a distinct resistance profile and that differences in resistance pathways may also impact on cross-resistance and the selection of second-line regimens. It will be essential to pay attention to newer drug combinations in well designed long-term longitudinal studies involving patients infected by viruses of different subtypes.
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Affiliation(s)
- Mark A Wainberg
- McGill University AIDS Centre, Jewish General Hospital, 3755 Cote-Ste-Catherine Road, Montreal, Quebec, H3T 1E2, Canada; E-Mail:
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Iordanskiy S, Waltke M, Feng Y, Wood C. Subtype-associated differences in HIV-1 reverse transcription affect the viral replication. Retrovirology 2010; 7:85. [PMID: 20939905 PMCID: PMC2964588 DOI: 10.1186/1742-4690-7-85] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 10/12/2010] [Indexed: 01/08/2023] Open
Abstract
Background The impact of the products of the pol gene, specifically, reverse transcriptase (RT) on HIV-1 replication, evolution, and acquisition of drug resistance has been thoroughly characterized for subtype B. For subtype C, which accounts of almost 60% of HIV cases worldwide, much less is known. It has been reported that subtype C HIV-1 isolates have a lower replication capacity than B; however, the basis of these differences remains unclear. Results We analyzed the impact of the pol gene products from HIV-1 B and C subtypes on the maturation of HIV virions, accumulation of reverse transcription products, integration of viral DNA, frequency of point mutations in provirus and overall viral replication. Recombinant HIV-1 viruses of B and C subtypes comprising the pol fragments encoding protease, integrase and either the whole RT or a chimeric RT from different isolates of the C and B subtypes, were used for infection of cells expressing CXCR4 or CCR5 co-receptors. The viruses carrying different fragments of pol from the isolates of B and C subtypes did not reveal differences in Gag and GagPol processing and viral RNA incorporation into the virions. However, the presence of the whole RT from subtype C, or the chimeric RT containing either the polymerase or the connection and RNase H domains from C isolates, caused significantly slower viral replication regardless of B or C viral backbone. Subtype C RT carrying viruses displayed lower levels of accumulation of strong-stop cDNA in permeabilized virions during endogenous reverse transcription, and decreased accumulation of both strong-stop and positive strand reverse transcription products in infected cells and in isolated reverse transcription complexes. This decreased accumulation correlated with lower levels of viral DNA integration in cells infected with viruses carrying the whole RT or RT domains from subtype C isolates. The single viral genome assay analysis did not reveal significant differences in the frequency of point mutations between the RT from B or C subtypes. Conclusions These data suggest that the whole RT as well as distinct polymerase and connection-RNase H domains from subtype C HIV-1 confer a lower level of accumulation of reverse transcripts in the virions and reverse transcription complexes as compared to subtype B, resulting in a lower overall level of virus replication.
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Affiliation(s)
- Sergey Iordanskiy
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, 4240 Fair Street, East Campus, Lincoln, NE 68583-0900 USA.
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Xu HT, Quan Y, Asahchop E, Oliveira M, Moisi D, Wainberg MA. Comparative biochemical analysis of recombinant reverse transcriptase enzymes of HIV-1 subtype B and subtype C. Retrovirology 2010; 7:80. [PMID: 20929562 PMCID: PMC2959035 DOI: 10.1186/1742-4690-7-80] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 10/07/2010] [Indexed: 11/10/2022] Open
Abstract
Background HIV-1 subtype C infections account for over half of global HIV infections, yet the vast focus of HIV-1 research has been on subtype B viruses which represent less than 12% of the global pandemic. Since HIV-1 reverse transcriptase (RT) is a major target of antiviral therapy, and since differential drug resistance pathways have been observed among different HIV subtypes, it is important to study and compare the enzymatic activities of HIV-1 RT derived from each of subtypes B and C as well as to determine the susceptibilities of these enzymes to various RT inhibitors in biochemical assays. Methods Recombinant subtype B and C HIV-1 RTs in heterodimeric form were purified from Escherichia coli and enzyme activities were compared in cell-free assays. The efficiency of (-) ssDNA synthesis was measured using gel-based assays with HIV-1 PBS RNA template and tRNA3Lys as primer. Processivity was assayed under single-cycle conditions using both homopolymeric and heteropolymeric RNA templates. Intrinsic RNase H activity was compared using 5'-end labeled RNA template annealed to 3'-end recessed DNA primer in a time course study in the presence and absence of a heparin trap. A mis-incorporation assay was used to assess the fidelity of the two RT enzymes. Drug susceptibility assays were performed both in cell-free assays using recombinant enzymes and in cell culture phenotyping assays. Results The comparative biochemical analyses of recombinant subtype B and subtype C HIV-1 reverse transcriptase indicate that the two enzymes are very similar biochemically in efficiency of tRNA-primed (-) ssDNA synthesis, processivity, fidelity and RNase H activity, and that both enzymes show similar susceptibilities to commonly used NRTIs and NNRTIs. Cell culture phenotyping assays confirmed these results. Conclusions Overall enzyme activity and drug susceptibility of HIV-1 subtype C RT are comparable to those of subtype B RT. The use of RT inhibitors (RTIs) against these two HIV-1 enzymes should have comparable effects.
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Affiliation(s)
- Hong-Tao Xu
- McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
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Abstract
PURPOSE OF REVIEW Microbicide research has been in the forefront of scientific literature in recent months. Results of large-scale clinical trials have been announced with resultant investigations into the factors that may have contributed to the disappointing outcomes of the most promising candidates. This review takes into consideration clinical, basic scientific and behavioural research published on microbicides in the past 12-18 months. RECENT FINDINGS Two trials testing PRO 2000, a sulphated polymer, suggested that it has no effect on HIV. Basic science research revealed several facts such as the loss of antiviral activity of microbicides in the presence of seminal plasma. Methodological models suggested that dilution factors might impact on measures of efficacy. Advancement into safety testing of highly specific antiretroviral products such as tenofovir and UC781 for both rectal and vaginal use shows promise. Development of drug delivery systems such as intravaginal rings may alleviate some of the adherence challenges faced when using coitally dependant products. SUMMARY In the recent past, microbicide research has had disappointing outcomes. However, it has also provided a better understanding of factors that may reduce effectiveness of promising products, enabling the field to be better equipped to select and test new products.
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The M230L nonnucleoside reverse transcriptase inhibitor resistance mutation in HIV-1 reverse transcriptase impairs enzymatic function and viral replicative capacity. Antimicrob Agents Chemother 2010; 54:2401-8. [PMID: 20308384 DOI: 10.1128/aac.01795-09] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The M230L mutation in HIV-1 reverse transcriptase (RT) is associated with resistance to first-generation nonnucleoside reverse transcriptase inhibitors (NNRTIs). The present study was designed to determine the effects of M230L on enzyme function, viral replication capacity (RC), and the extent to which M230L might confer resistance to the second-generation NNRTI etravirine (ETR) as well as to the first-generation NNRTIs efavirenz (EFV) and nevirapine (NVP). Phenotyping assays with TZM-bl cells confirmed that M230L conferred various degrees of resistance to each of the NNRTIs tested. Recombinant viruses containing M230L displayed an 8-fold decrease in RC compared to that of the parental wild-type (WT) virus. Recombinant HIV-1 WT and M230L mutant RT enzymes were purified; and both biochemical and cell-based phenotypic assays confirmed that M230L conferred resistance to each of EFV, NVP, and ETR. RT that contained M230L was also deficient in regard to each of minus-strand DNA synthesis, both DNA- and RNA-dependent polymerase activities, processivity, and RNase H activity, suggesting that this mutation contributes to diminished viral replication kinetics.
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Coutsinos D, Invernizzi CF, Xu H, Brenner BG, Wainberg MA. Factors Affecting Template Usage in the Development of K65R Resistance in Subtype C Variants of HIV Type-1. ACTA ACUST UNITED AC 2010; 20:117-31. [DOI: 10.3851/imp1443] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Background: We have shown that the K65R resistance mutation in HIV type-1 (HIV-1) reverse transcriptase (RT) is selected more rapidly in subtype C than subtype B HIV-1 in biochemical, cell culture and clinical studies. Template-usage experiments demonstrated that subtype C nucleotide coding sequences caused RT to preferentially pause, leading to K65R acquisition. This new study now further establishes the basis for differential occurrence of both K65R and thymidine analogue mutations (TAMs) between subtypes. Methods: Gel-based nucleotide extension assays were used to study the homopolymeric sequence surrounding K65. Results: When positive double-stranded DNA synthesis was evaluated from a negative single-stranded DNA template, pausing at the 67 region, which is linked to occurrence of TAMs, was alleviated with both subtype B and C templates at high dCTP concentrations, but this alleviation was more pronounced with the subtype C template. By contrast, pausing at the 65 region on the subtype C but not subtype B template always occurred and was not alleviated at high levels of nucleotide triphosphates or by other means. Furthermore, templates containing repeats of the homopolymeric sequence spanning codons 64–66 of pol showed corresponding pausing repeats at the 65 region with the subtype C template only. Inverted RNA and DNA templates both displayed pausing at position K65 for the subtype C template and a ladder of pausing events culminating at codon 67 for the subtype B templates. Conclusions: These results further establish a mechanistic basis for the exclusion of both K65R and TAMs on single templates as well as the preferential acquisition of K65R in subtype C viruses.
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Affiliation(s)
- Dimitrios Coutsinos
- McGill University AIDS Center, Jewish General Hospital, Montréal, QC, Canada
- Department of Microbiology and Immunology, McGill University, Montréal, QC, Canada
- Department of Medicine, McGill University, Montréal, QC, Canada
| | - Cédric F Invernizzi
- McGill University AIDS Center, Jewish General Hospital, Montréal, QC, Canada
- Department of Medicine, McGill University, Montréal, QC, Canada
| | - Hongtao Xu
- McGill University AIDS Center, Jewish General Hospital, Montréal, QC, Canada
| | - Bluma G Brenner
- McGill University AIDS Center, Jewish General Hospital, Montréal, QC, Canada
- Department of Medicine, McGill University, Montréal, QC, Canada
| | - Mark A Wainberg
- McGill University AIDS Center, Jewish General Hospital, Montréal, QC, Canada
- Department of Microbiology and Immunology, McGill University, Montréal, QC, Canada
- Department of Medicine, McGill University, Montréal, QC, Canada
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Bar-Magen T, Sloan RD, Faltenbacher VH, Donahue DA, Kuhl BD, Oliveira M, Xu H, Wainberg MA. Comparative biochemical analysis of HIV-1 subtype B and C integrase enzymes. Retrovirology 2009; 6:103. [PMID: 19906306 PMCID: PMC2779801 DOI: 10.1186/1742-4690-6-103] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 11/11/2009] [Indexed: 12/03/2022] Open
Abstract
Background Integrase inhibitors are currently being incorporated into highly active antiretroviral therapy (HAART). Due to high HIV variability, integrase inhibitor efficacy must be evaluated against a range of integrase enzymes from different subtypes. Methods This study compares the enzymatic activities of HIV-1 integrase from subtypes B and C as well as susceptibility to various integrase inhibitors in vitro. The catalytic activities of both enzymes were analyzed in regard to each of 3' processing and strand transfer activities both in the presence and absence of the integrase inhibitors raltegravir (RAL), elvitegravir (EVG), and MK-2048. Results Our results show that integrase function is similar with enzymes of either subtype and that the various integrase strand transfer inhibitors (INSTIs) that were employed possessed similar inhibitory activity against both enzymes. Conclusion This suggests that the use of integrase inhibitors against HIV-1 subtype C will result in comparable outcomes to those obtained against subtype B infections.
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Affiliation(s)
- Tamara Bar-Magen
- McGill University AIDS Centre, Lady Davis Institute-Jewish General Hospital, Montreal, Quebec, Canada.
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38
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Brenner BG, Coutsinos D. The K65R mutation in HIV-1 reverse transcriptase: genetic barriers, resistance profile and clinical implications. ACTA ACUST UNITED AC 2009; 3:583-594. [PMID: 20190870 DOI: 10.2217/hiv.09.40] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Resistance to antiviral therapy is the limiting factor in the successful management of HIV. In general, the K65R mutation is rarely selected (1.7-4%) with tenofovir disoproxil fumarate (TDF), abacavir (ABC), didanosine (ddI), and stavudine (d4T), as compared with the high incidence (>40%) of thymidine analog mutations associated with zidovudine and d4T. The high barrier to the development of K65R may reflect a combination of factors, including the high potency of K65R-selecting drugs, including recommended TDF/emtricitabine and ABC/lamivudine (ABC/3TC) combinations; the partial (low-intermediate level) profile of cross-resistance conferred by K65R to TDF, ABC and 3TC; the favorable viral fitness constraint imposed by K65R and the 3TC/emtricitabine-associated M184V mutations; the bidirectional antagonism between the K65R and thymidine analog mutation pathways; and unique RNA structural considerations in the region surrounding codon 65. Nevertheless, surprisingly high levels of treatment failures and K65R resistance may be associated with triple nucleoside analog regimens. The use of TDF + ABC, TDF + ddI and ABC + d4T in combination with 3TC or emtricitabine should be avoided. This selection of K65R may be reduced by the inclusion of zidovudine in two-four nucleoside reverse-transcriptase regimens. Clinical studies have demonstrated an increased frequency of K65R in association with suboptimal d4T and ddI regimens, as well as nevirapine and its resistance mutations Y181C and G190A. The potential for the development of the K65R mutation in subtype C is particularly problematic wherein a signature KKK nucleotide motif, at codons 64, 65 and 66 in reverse transcriptase, appear to lead to template pausing, facilitating the selection of K65R. Optimizing regimens may attenuate the emergence of K65R, leading to better long-term treatment management in different geographic settings. TDF-based regimens are the leading candidates for first- and second-line therapy, microbicides and chemoprophylaxis strategies.
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Affiliation(s)
- Bluma G Brenner
- McGill AIDS Centre, Lady Davis Institute, 3755 Cote Ste. Catherine Road, Montreal, Quebec, H3T 1E2, Canada
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Wester CW, Bussmann H, Koethe J, Moffat C, Vermund S, Essex M, Marlink RG. Adult combination antiretroviral therapy in sub-Saharan Africa: lessons from Botswana and future challenges. HIV THERAPY 2009; 3:501-526. [PMID: 20161344 PMCID: PMC2774911 DOI: 10.2217/hiv.09.35] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Numerous national public initiatives offering first-line combination antiretroviral therapy (cART) for HIV infection have commenced in sub-Saharan Africa since 2002. Presently, 2.1 million of an estimated seven million Africans in need of cART are receiving treatment. Analyses from the region report favorable clinical/treatment outcomes and impressive declines in AIDS-related mortality among HIV-1-infected adults and children receiving cART. While immunologic recovery, virologic suppression and cART adherence rates are on par with resource-rich settings, loss to follow-up and high mortality rates, especially within the first 6 months of treatment, remain a significant problem. Over the next decade, cART coverage rates are expected to improve across the region, with attendant increases in healthcare utilization for HIV- and non-HIV-related complications and the need for expanded laboratory and clinical services. Planned and in-progress trials will evaluate the use of cART to prevent primary HIV-1 infection with so-called 'test and treat' expansions of coverage and treatment. Education and training programs as well as patient-retention strategies will need to be strengthened as national cART programs are expanded and more people require lifelong monitoring and care.
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Affiliation(s)
- C William Wester
- Botswana-Harvard School of Public Health AIDS Initiative Partnership for HIV Research & Education (BHP), Gaborone, Botswana
- Harvard School of Public Health, Department of Immunology & Infectious Diseases, Boston, MA, USA
- Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Institute of Global Health (VIGH), Vanderbilt University, Nashville, TN, USA
| | - Hermann Bussmann
- Botswana-Harvard School of Public Health AIDS Initiative Partnership for HIV Research & Education (BHP), Gaborone, Botswana
- Harvard School of Public Health, Department of Immunology & Infectious Diseases, Boston, MA, USA
| | - John Koethe
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Claire Moffat
- Botswana-Harvard School of Public Health AIDS Initiative Partnership for HIV Research & Education (BHP), Gaborone, Botswana
- Harvard School of Public Health, Department of Immunology & Infectious Diseases, Boston, MA, USA
| | - Sten Vermund
- Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Institute of Global Health (VIGH), Vanderbilt University, Nashville, TN, USA
| | - Max Essex
- Botswana-Harvard School of Public Health AIDS Initiative Partnership for HIV Research & Education (BHP), Gaborone, Botswana
- Harvard School of Public Health, Department of Immunology & Infectious Diseases, Boston, MA, USA
| | - Richard G Marlink
- Botswana-Harvard School of Public Health AIDS Initiative Partnership for HIV Research & Education (BHP), Gaborone, Botswana
- Harvard School of Public Health, Department of Immunology & Infectious Diseases, Boston, MA, USA
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Martinez-Cajas JL, Pai NP, Klein MB, Wainberg MA. Differences in resistance mutations among HIV-1 non-subtype B infections: a systematic review of evidence (1996-2008). J Int AIDS Soc 2009; 12:11. [PMID: 19566959 PMCID: PMC2713201 DOI: 10.1186/1758-2652-12-11] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Accepted: 06/30/2009] [Indexed: 11/23/2022] Open
Abstract
Ninety percent of HIV-1-infected people worldwide harbour non-subtype B variants of HIV-1. Yet knowledge of resistance mutations in non-B HIV-1 and their clinical relevance is limited. Although a few reviews, editorials and perspectives have been published alluding to this lack of data among non-B subtypes, no systematic review has been performed to date.With this in mind, we conducted a systematic review (1996-2008) of all published studies performed on the basis of non-subtype B HIV-1 infections treated with antiretroviral drugs that reported genotype resistance tests. Using an established search string, 50 studies were deemed relevant for this review.These studies reported genotyping data from non-B HIV-1 infections that had been treated with either reverse transcriptase inhibitors or protease inhibitors. While most major resistance mutations in subtype B were also found in non-B subtypes, a few novel mutations in non-B subtypes were recognized. The main differences are reflected in the discoveries that: (i) the non-nucleoside reverse transcriptase inhibitor resistance mutation, V106M, has been seen in subtype C and CRF01_AE, but not in subtype B, (ii) the protease inhibitor mutations L89I/V have been reported in C, F and G subtypes, but not in B, (iii) a nelfinavir selected non-D30N containing pathway predominated in CRF01_AE and CRF02_AG, while the emergence of D30N is favoured in subtypes B and D, (iv) studies on thymidine analog-treated subtype C infections from South Africa, Botswana and Malawi have reported a higher frequency of the K65R resistance mutation than that typically seen with subtype B.Additionally, some substitutions that seem to impact non-B viruses differentially are: reverse transcriptase mutations G196E, A98G/S, and V75M; and protease mutations M89I/V and I93L.Polymorphisms that were common in non-B subtypes and that may contribute to resistance tended to persist or become more frequent after drug exposure. Some, but not all, are recognized as minor resistance mutations in B subtypes. These observed differences in resistance pathways may impact cross-resistance and the selection of second-line regimens with protease inhibitors. Attention to newer drug combinations, as well as baseline genotyping of non-B isolates, in well-designed longitudinal studies with long duration of follow up are needed.
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Affiliation(s)
- Jorge L Martinez-Cajas
- Department of Medicine, Infectious Diseases, Queen's University, Kingston, Ontario, Canada
| | - Nitika P Pai
- McGill University Health Centre, Montreal, Quebec, Canada
| | - Marina B Klein
- McGill University Health Centre, Montreal, Quebec, Canada
| | - Mark A Wainberg
- McGill University AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada
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Sharma PL, Nettles JH, Feldman A, Rapp K, Schinazi RF. Comparative analysis of in vitro processivity of HIV-1 reverse transcriptases containing mutations 65R, 74V, 184V and 65R+74V. Antiviral Res 2009; 83:317-23. [PMID: 19555722 DOI: 10.1016/j.antiviral.2009.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/27/2009] [Accepted: 06/15/2009] [Indexed: 11/29/2022]
Abstract
While HIV-1 reverse transcriptase (RT) mutations of M to V at position 184 are commonly observed in the clinic, the double mutation of 65R+74V is rarely seen. It has been demonstrated that rapid R-->K reversion occurs at RT codon 65 during replication of HIV-1 in human peripheral blood mononuclear cells containing 65R+74V mutations and that processivity of the RT is reduced relative to wild type. However, clinical studies show that M184V can be detected after several months of therapy interruption, suggesting more effective processivity. Herein, the in vitro RT processivity of genetically engineered M184V and double mutant 65R+74V was compared. Virion-associated RTs of WT pNL4-3, K65R, L74V, M184V and 65R+74V were used to perform RT processivity assays in the presence of trap, poly(rC)-oligo(dG). Both RTs with 184V and 65R+74V mutations exhibited similar processivity when compared with each other and a significantly decreased processivity as compared to WT RT. Both mutant RTs synthesized shorter cDNA molecules (37-42 nt) relative to WT RT, which made longer (65-70 nt) cDNA molecules. Since these surprising biochemical results cannot explain the clinical phenotype, a hypothesis is presented to explain the discrepancy and suggest new approaches for future testing.
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Affiliation(s)
- Prem L Sharma
- Center for AIDS Research , Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, United States.
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