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Fombellida-Lopez C, Berkhout B, Darcis G, Pasternak AO. Persistent HIV-1 transcription during ART: time to reassess its significance? Curr Opin HIV AIDS 2024; 19:124-132. [PMID: 38502547 PMCID: PMC10990031 DOI: 10.1097/coh.0000000000000849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
PURPOSE OF REVIEW Despite suppressive antiretroviral therapy (ART), HIV-1 reservoirs persist and reignite viral replication if therapy is interrupted. Persistence of the viral reservoir in people with HIV-1 (PWH) is the main obstacle to an HIV-1 cure. The reservoirs are not transcriptionally silent, and viral transcripts can be detected in most ART-treated individuals. Here, we review the recent progress in the characterization of persistent HIV-1 transcription during ART. RECENT FINDINGS Evidence from several studies indicates that, although cell-associated unspliced (US) HIV-1 RNA is abundantly expressed in ART-treated PWH, intact full-length US transcripts are rare and most US RNA is derived from defective proviruses. The transcription- and translation-competent defective proviruses, previously considered irrelevant, are increasingly being linked to residual HIV-1 pathogenesis under suppressive ART. Recent data suggest a continuous crosstalk between the residual HIV-1 activity under ART and the immune system. Persistent HIV-1 transcription on ART, despite being mostly derived from defective proviruses, predicts viral rebound upon therapy interruption, suggesting its role as an indicator of the strength of the host antiviral immune response that is shaping the viral rebound. SUMMARY In light of the recent findings, the significance of persistent HIV-1 transcription during ART for the long-term health of PWH and the cure research should be reassessed.
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Affiliation(s)
- Céline Fombellida-Lopez
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory of Immunology and Infectious Diseases, GIGA-Institute, University of Liège
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Gilles Darcis
- Laboratory of Immunology and Infectious Diseases, GIGA-Institute, University of Liège
- Department of General Internal Medicine and Infectious Diseases, University Hospital of Liège, Liège, Belgium
| | - Alexander O. Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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Pasternak AO, Tsukamoto T, Berkhout B. 'Zombie' proviruses in the spotlight: exploring the dark side of HIV persistence. AIDS 2023; 37:2239-2241. [PMID: 37877277 DOI: 10.1097/qad.0000000000003721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Tetsuo Tsukamoto
- Department of Health Informatics, Niigata University of Health and Welfare, Niigata, Japan
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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Pasternak AO, Rohr O, Van Lint C, Kula-Pacurar A. Corrigendum: Editorial: The relevance of molecular mechanisms in HIV-1 latency and reactivation from latency. Front Cell Infect Microbiol 2023; 13:1213356. [PMID: 37249980 PMCID: PMC10210130 DOI: 10.3389/fcimb.2023.1213356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/31/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fcimb.2023.1190867.].
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Affiliation(s)
- Alexander O. Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Olivier Rohr
- Laboratoire de Dynamique des Interactions Hôte-Pathogènes EA7292, Université de Strasbourg, Schiltigheim, France
- Institut Universitaire de Technologie Louis Pasteur, Université de Strasbourg, Schiltigheim, France
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Anna Kula-Pacurar
- Virogenetics Laboratory of Virology, Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
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Pasternak AO, Rohr O, Van Lint C, Kula-Pacurar A. Editorial: The relevance of molecular mechanisms in HIV-1 latency and reactivation from latency. Front Cell Infect Microbiol 2023; 13:1190867. [PMID: 37077527 PMCID: PMC10107405 DOI: 10.3389/fcimb.2023.1190867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 04/05/2023] Open
Affiliation(s)
- Alexander O. Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands
- *Correspondence: Alexander O. Pasternak,
| | - Olivier Rohr
- Laboratoire de Dynamique des Interactions Hôte-Pathogènes EA7292, Université de Strasbourg, Schiltigheim, France
- Institut Universitaire de Technologie Louis Pasteur, Université de Strasbourg, Schiltigheim, France
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Anna Kula-Pacurar
- Virogenetics Laboratory of Virology, Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
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Pasternak AO, Berkhout B. HIV persistence: silence or resistance? Curr Opin Virol 2023; 59:101301. [PMID: 36805974 DOI: 10.1016/j.coviro.2023.101301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/05/2022] [Accepted: 12/19/2022] [Indexed: 02/19/2023]
Abstract
Despite decades of suppressive antiretroviral therapy, human immunodeficiency virus (HIV) reservoirs in infected individuals persist and fuel viral rebound once therapy is interrupted. The persistence of viral reservoirs is the main obstacle to achieving HIV eradication or a long-term remission. The last decade has seen a profound change in our understanding of the mechanisms behind HIV persistence, which appears to be much more complex than originally assumed. In addition to the persistence of transcriptionally silent proviruses in a stable latent reservoir that is invisible to the immune system, HIV is increasingly recognized to persist by resistance to the immune clearance, which appears to play a surprisingly prominent role in shaping the reservoir. In this review, we discuss some emerging insights into the mechanisms of HIV persistence, as well as their implications for the development of strategies towards an HIV cure.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
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Adams P, Berkhout B, Pasternak AO. Towards a molecular profile of antiretroviral therapy-free HIV remission. Curr Opin HIV AIDS 2022; 17:301-307. [PMID: 35938464 DOI: 10.1097/coh.0000000000000749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW To summarize the current status and highlight recent findings on predictive biomarkers for posttreatment HIV control (PTC) and virological remission. While historically, many studies focused on virological markers, there is an increasing tendency to enter immune and metabolic factors into the equation. RECENT FINDINGS On the virological side, several groups reported that cell-associated HIV RNA could predict time to viral rebound. Recent data hints at the possible importance of the genic location and chromatin context of the integrated provirus, although these factors still need to be assessed in relation to PTC and virological remission. Evidence from immunological studies highlighted innate and humoral immunity as important factors for prolonged HIV remission. Interestingly, novel metabolic markers have emerged, which offer additional angles to our understanding of latency and viral rebound. SUMMARY Facilitating PTC and virological remission remain top priorities for the HIV cure research. We advocate for clear and precise definitions for both phenomena in order to avoid misconceptions and to strengthen the conclusions that can be drawn. As no one-size-fits-all marker has emerged yet, more biomarkers are on the horizon, and viral rebound is a complex and heterogeneous process, it is likely that a combination of various biomarkers in cohesion will be necessary for a more accurate prediction of antiretroviral therapy-free HIV remission.
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Affiliation(s)
- Philipp Adams
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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Verdikt R, Bendoumou M, Bouchat S, Nestola L, Pasternak AO, Darcis G, Avettand-Fenoel V, Vanhulle C, Aït-Ammar A, Santangelo M, Plant E, Douce VL, Delacourt N, Cicilionytė A, Necsoi C, Corazza F, Passaes CPB, Schwartz C, Bizet M, Fuks F, Sáez-Cirión A, Rouzioux C, De Wit S, Berkhout B, Gautier V, Rohr O, Van Lint C. Novel role of UHRF1 in the epigenetic repression of the latent HIV-1. EBioMedicine 2022; 79:103985. [PMID: 35429693 PMCID: PMC9038550 DOI: 10.1016/j.ebiom.2022.103985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The multiplicity, heterogeneity, and dynamic nature of human immunodeficiency virus type-1 (HIV-1) latency mechanisms are reflected in the current lack of functional cure for HIV-1. Accordingly, all classes of latency-reversing agents (LRAs) have been reported to present variable ex vivo potencies. Here, we investigated the molecular mechanisms underlying the potency variability of one LRA: the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-AzadC). METHODS We employed epigenetic interrogation methods (electrophoretic mobility shift assays, chromatin immunoprecipitation, Infinium array) in complementary HIV-1 infection models (latently-infected T-cell line models, primary CD4+ T-cell models and ex vivo cultures of PBMCs from HIV+ individuals). Extracellular staining of cell surface receptors and intracellular metabolic activity were measured in drug-treated cells. HIV-1 expression in reactivation studies was explored by combining the measures of capsid p24Gag protein, green fluorescence protein signal, intracellular and extracellular viral RNA and viral DNA. FINDINGS We uncovered specific demethylation CpG signatures induced by 5-AzadC in the HIV-1 promoter. By analyzing the binding modalities to these CpG, we revealed the recruitment of the epigenetic integrator Ubiquitin-like with PHD and RING finger domain 1 (UHRF1) to the HIV-1 promoter. We showed that UHRF1 redundantly binds to the HIV-1 promoter with different binding modalities where DNA methylation was either non-essential, essential or enhancing UHRF1 binding. We further demonstrated the role of UHRF1 in the epigenetic repression of the latent viral promoter by a concerted control of DNA and histone methylations. INTERPRETATION A better understanding of the molecular mechanisms of HIV-1 latency allows for the development of innovative antiviral strategies. As a proof-of-concept, we showed that pharmacological inhibition of UHRF1 in ex vivo HIV+ patient cell cultures resulted in potent viral reactivation from latency. Together, we identify UHRF1 as a novel actor in HIV-1 epigenetic silencing and highlight that it constitutes a new molecular target for HIV-1 cure strategies. FUNDING Funding was provided by the Belgian National Fund for Scientific Research (F.R.S.-FNRS, Belgium), the « Fondation Roi Baudouin », the NEAT (European AIDS Treatment Network) program, the Internationale Brachet Stiftung, ViiV Healthcare, the Télévie, the Walloon Region (« Fonds de Maturation »), « Les Amis des Instituts Pasteur à Bruxelles, asbl », the University of Brussels (Action de Recherche Concertée ULB grant), the Marie Skodowska Curie COFUND action, the European Union's Horizon 2020 research and innovation program under grant agreement No 691119-EU4HIVCURE-H2020-MSCA-RISE-2015, the French Agency for Research on AIDS and Viral Hepatitis (ANRS), the Sidaction and the "Alsace contre le Cancer" Foundation. This work is supported by 1UM1AI164562-01, co-funded by National Heart, Lung and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Neurological Disorders and Stroke, National Institute on Drug Abuse and the National Institute of Allergy and Infectious Diseases.
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Affiliation(s)
- Roxane Verdikt
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Maryam Bendoumou
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Sophie Bouchat
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Lorena Nestola
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Alexander O Pasternak
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam 1105 AZ, the Netherland
| | - Gilles Darcis
- Infectious Diseases Department, Liège University Hospital, Liège 4000, Belgium
| | - Véronique Avettand-Fenoel
- AP-HP, Hôpital Necker-Enfants-Malades, Service de Microbiologie clinique, Paris 75015, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75006, France; INSERM, U1016, Institut Cochin, Paris, 75014, France; CNRS, UMR8104, Paris 75014, France
| | - Caroline Vanhulle
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Amina Aït-Ammar
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Marion Santangelo
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Estelle Plant
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Valentin Le Douce
- Centre for Research in Infectious Diseases, University College Dublin, Dublin 4, Ireland
| | - Nadège Delacourt
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium
| | - Aurelija Cicilionytė
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam 1105 AZ, the Netherland
| | - Coca Necsoi
- Service des Maladies Infectieuses, CHU St-Pierre, Université Libre de Bruxelles (ULB), Brussels 1000, Belgium
| | - Francis Corazza
- Laboratory of Immunology, IRISLab, CHU Brugmann, Université Libre de Bruxelles (ULB), Brussels 1020, Belgium
| | | | - Christian Schwartz
- Laboratoire DHPI EA7292, Université de Strasbourg, Schiltigheim, 67300, France; IUT Louis Pasteur, Université de Strasbourg, Schiltigheim, 67300, France
| | - Martin Bizet
- Laboratory of Cancer Epigenetics, Faculty of Medicine, ULB-Cancer Research Center (U-CRC), Université Libre de Bruxelles (ULB), Brussels 1070, Belgium
| | - François Fuks
- Laboratory of Cancer Epigenetics, Faculty of Medicine, ULB-Cancer Research Center (U-CRC), Université Libre de Bruxelles (ULB), Brussels 1070, Belgium
| | - Asier Sáez-Cirión
- Départements de Virologie et Immunologie, Institut Pasteur, Unité HIV, Inflammation et Persistance, Paris 75015, France
| | - Christine Rouzioux
- AP-HP, Hôpital Necker-Enfants-Malades, Service de Microbiologie clinique, Paris 75015, France
| | - Stéphane De Wit
- Service des Maladies Infectieuses, CHU St-Pierre, Université Libre de Bruxelles (ULB), Brussels 1000, Belgium
| | - Ben Berkhout
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam 1105 AZ, the Netherland
| | - Virginie Gautier
- Centre for Research in Infectious Diseases, University College Dublin, Dublin 4, Ireland
| | - Olivier Rohr
- Laboratoire DHPI EA7292, Université de Strasbourg, Schiltigheim, 67300, France; IUT Louis Pasteur, Université de Strasbourg, Schiltigheim, 67300, France
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Biology (DBM), Université Libre de Bruxelles (ULB), Gosselies 6041, Belgium.
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Pasternak AO, Berkhout B. The Splice of Life: Does RNA Processing Have a Role in HIV-1 Persistence? Viruses 2021; 13:v13091751. [PMID: 34578332 PMCID: PMC8471011 DOI: 10.3390/v13091751] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 12/28/2022] Open
Abstract
Antiretroviral therapy (ART) suppresses HIV-1 replication but does not eradicate the virus. Persistence of HIV-1 latent reservoirs in ART-treated individuals is considered the main obstacle to achieving an HIV-1 cure. However, these HIV-1 reservoirs are not transcriptionally silent, and viral transcripts can be detected in most ART-treated individuals. HIV-1 latency is regulated at the transcriptional and at multiple post-transcriptional levels. Here, we review recent insights into the possible contribution of viral RNA processing to the persistence of HIV-1 reservoirs, and discuss the clinical implications of persistence of viral RNA species in ART-treated individuals.
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Pinzone MR, Weissman S, Pasternak AO, Zurakowski R, Migueles S, O'Doherty U. Naive infection predicts reservoir diversity and is a formidable hurdle to HIV eradication. JCI Insight 2021; 6:e150794. [PMID: 34228640 PMCID: PMC8409977 DOI: 10.1172/jci.insight.150794] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/30/2021] [Indexed: 12/16/2022] Open
Abstract
Historically, naive cells have been considered inconsequential to HIV persistence. Here, we compared the contributions of naive and memory cells to the reservoirs of individuals with a spectrum of reservoir sizes and variable immunological control. We performed proviral sequencing of approximately 6000 proviruses from cellular subsets of 5 elite controllers (ECs) off antiretroviral therapy (ART) and 5 chronic progressors (CPs) on ART. The levels of naive infection were barely detectable in ECs and approximately 300-fold lower compared with those in CPs. Moreover, the ratio of infected naive to memory cells was significantly lower in ECs. Overall, the naive infection level increased as reservoir size increased, such that naive cells were a major contributor to the intact reservoir of CPs, whose reservoirs were generally very diverse. In contrast, the reservoirs of ECs were dominated by proviral clones. Critically, the fraction of proviral clones increased with cell differentiation, with naive infection predicting reservoir diversity. Longitudinal sequencing revealed that the reservoir of ECs was less dynamic compared with that of CPs. Naive cells play a critical role in HIV persistence. Their infection level predicts reservoir size and diversity. Moreover, the diminishing diversity of the reservoir as cellular subsets mature suggests that naive T cells repopulate the memory compartment and that direct infection of naive T cells occurs in vivo.
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Affiliation(s)
- Marilia R Pinzone
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sam Weissman
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alexander O Pasternak
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Virology, Amsterdam, Netherlands
| | - Ryan Zurakowski
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Stephen Migueles
- HIV-Specific Immunity Section of the Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, USA
| | - Una O'Doherty
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Pasternak AO, Vroom J, Kootstra NA, Wit FW, de Bruin M, De Francesco D, Bakker M, Sabin CA, Winston A, Prins JM, Reiss P, Berkhout B. Non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy is associated with lower cell-associated HIV RNA and DNA levels as compared with therapy based on protease inhibitors. eLife 2021; 10:68174. [PMID: 34387543 PMCID: PMC8460250 DOI: 10.7554/elife.68174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 08/07/2021] [Indexed: 11/28/2022] Open
Abstract
Background: It remains unclear whether combination antiretroviral therapy (ART) regimens differ in their ability to fully suppress human immunodeficiency virus (HIV) replication. Here, we report the results of two cross-sectional studies that compared levels of cell-associated (CA) HIV markers between individuals receiving suppressive ART containing either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI). Methods: CA HIV unspliced RNA and total HIV DNA were quantified in two cohorts (n = 100, n = 124) of individuals treated with triple ART regimens consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) plus either an NNRTI or a PI. To compare CA HIV RNA and DNA levels between the regimens, we built multivariable models adjusting for age, gender, current and nadir CD4+ count, plasma viral load zenith, duration of virological suppression, NRTI backbone composition, low-level plasma HIV RNA detectability, and electronically measured adherence to ART. Results: In both cohorts, levels of CA HIV RNA and DNA strongly correlated (rho = 0.70 and rho = 0.54) and both markers were lower in NNRTI-treated than in PI-treated individuals. In the multivariable analysis, CA RNA in both cohorts remained significantly reduced in NNRTI-treated individuals (padj = 0.02 in both cohorts), with a similar but weaker association between the ART regimen and total HIV DNA (padj = 0.048 and padj = 0.10). No differences in CA HIV RNA or DNA levels were observed between individual NNRTIs or individual PIs, but CA HIV RNA was lower in individuals treated with either nevirapine or efavirenz, compared to PI-treated individuals. Conclusions: All current classes of antiretroviral drugs only prevent infection of new cells but do not inhibit HIV RNA transcription in long-lived reservoir cells. Therefore, these differences in CA HIV RNA and DNA levels by treatment regimen suggest that NNRTIs are more potent in suppressing HIV residual replication than PIs, which may result in a smaller viral reservoir size. Funding: This work was supported by ZonMw (09120011910035) and FP7 Health (305522).
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Affiliation(s)
- Alexander O Pasternak
- Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Jelmer Vroom
- Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Neeltje A Kootstra
- Experimental Immunology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ferdinand Wnm Wit
- Global Health, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Marijn de Bruin
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Davide De Francesco
- Institute for Global Health, University College London, London, United Kingdom
| | - Margreet Bakker
- Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Caroline A Sabin
- Institute for Global Health, University College London, London, United Kingdom
| | - Alan Winston
- Medicine, Imperial College London, London, United Kingdom
| | - Jan M Prins
- Internal Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, New Caledonia
| | - Peter Reiss
- Global Health, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ben Berkhout
- Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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Darcis G, Kootstra NA, Hooibrink B, van Montfort T, Maurer I, Groen K, Jurriaans S, Bakker M, van Lint C, Berkhout B, Pasternak AO. CD32 +CD4 + T Cells Are Highly Enriched for HIV DNA and Can Support Transcriptional Latency. Cell Rep 2021; 30:2284-2296.e3. [PMID: 32075737 PMCID: PMC7050565 DOI: 10.1016/j.celrep.2020.01.071] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 11/25/2019] [Accepted: 01/21/2020] [Indexed: 02/07/2023] Open
Abstract
The HIV latent reservoir forms the major hurdle to an HIV cure. The discovery of CD32 as marker of this reservoir has aroused much interest, but subsequent reports have challenged this finding. Here, we observe a positive correlation between the percentages of CD32+ cells among CD4+ T cells of aviremic cART-treated, HIV-infected individuals and their HIV DNA loads in peripheral blood. Moreover, optimization of the CD32+CD4+ T cell purification protocol reveals prominent enrichment for HIV DNA (mean, 292-fold) in these cells. However, no enrichment for HIV RNA is observed in CD32+CD4+ cells, yielding significantly reduced HIV RNA/DNA ratios. Furthermore, HIV proviruses in CD32+CD4+ cells can be reactivated ex vivo to produce virus, strongly suggesting that these cells support HIV transcriptional latency. Our results underscore the importance of isolating pure, bona fide CD32+CD4+ T cells for future studies and indicate that CD32 remains a promising candidate marker of the HIV reservoir.
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Affiliation(s)
- Gilles Darcis
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands; Infectious Diseases Department, Liège University Hospital, Liège, Belgium.
| | - Neeltje A Kootstra
- Laboratory of Viral Immune Pathogenesis, Department of Experimental Immunology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Berend Hooibrink
- Department of Cell Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Thijs van Montfort
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Irma Maurer
- Laboratory of Viral Immune Pathogenesis, Department of Experimental Immunology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Kevin Groen
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Suzanne Jurriaans
- Laboratory of Clinical Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Margreet Bakker
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Carine van Lint
- Service of Molecular Virology, Département de Biologie Moléculaire (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.
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Pasternak AO, Psomas CK, Berkhout B. Predicting Post-treatment HIV Remission: Does Size of the Viral Reservoir Matter? Front Microbiol 2021; 12:648434. [PMID: 33717047 PMCID: PMC7952863 DOI: 10.3389/fmicb.2021.648434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/08/2021] [Indexed: 12/19/2022] Open
Abstract
Combination antiretroviral therapy (ART) suppresses human immunodeficiency virus (HIV) replication and improves immune function. However, due to the persistence of long-lived HIV reservoirs, therapy interruption almost inevitably leads to a fast viral rebound. A small percentage of individuals who are able to control HIV replication for extended periods after therapy interruption are of particular interest because they may represent a model of long-term HIV remission without ART. These individuals are characterized by a limited viral reservoir and low reservoir measures can predict post-treatment HIV remission. However, most individuals with a low reservoir still experience fast viral rebound. In this Perspective, we discuss the possible reasons behind this and propose to develop an integral profile, composed of viral and host biomarkers, that could allow the accurate prediction of post-treatment HIV remission. We also propose to incorporate information on the chromatin context of the proviral integration sites into the characterization of the HIV reservoir, as this likely influences the reactivation capacity of latent proviruses and, together with the actual number of intact proviruses, contributes to the replication competence of the reservoir.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Christina K Psomas
- Department of Infectious Diseases and Internal Medicine, European Hospital, Marseille, France
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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13
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Pasternak AO, Grijsen ML, Wit FW, Bakker M, Jurriaans S, Prins JM, Berkhout B. Cell-associated HIV-1 RNA predicts viral rebound and disease progression after discontinuation of temporary early ART. JCI Insight 2020; 5:134196. [PMID: 32097124 DOI: 10.1172/jci.insight.134196] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 02/19/2020] [Indexed: 11/17/2022] Open
Abstract
Plasma viral load (VL) and CD4+ T cell count are widely used as biomarkers of HIV type 1 (HIV-1) replication, pathogenesis, and response to antiretroviral therapy (ART). However, the clinical potential of cell-associated (CA) HIV-1 molecular markers is much less understood. Here, we measured CA HIV-1 RNA and DNA in HIV-infected individuals treated with temporary ART initiated during primary HIV-1 infection. We demonstrate substantial predictive value of CA RNA for (a) the virological and immunological response to early ART, (b) the magnitude and time to viral rebound after discontinuation of early ART, and (c) disease progression in the absence of treatment. Remarkably, when adjusted for CA RNA, plasma VL no longer appeared as an independent predictor of any clinical endpoint in this cohort. The potential of CA RNA as an HIV-1 clinical marker, in particular as a predictive biomarker of virological control after stopping ART, should be explored in the context of HIV-1 curative interventions.
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Affiliation(s)
| | - Marlous L Grijsen
- Department of Internal Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ferdinand W Wit
- Department of Internal Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Global Health program, Amsterdam Public Health research institute, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Amsterdam Institute for Global Health and Development, Amsterdam, Netherlands.,HIV Monitoring Foundation, Amsterdam, Netherlands
| | - Margreet Bakker
- Laboratory of Experimental Virology, Department of Medical Microbiology, and
| | - Suzanne Jurriaans
- Laboratory of Clinical Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Jan M Prins
- Department of Internal Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, and
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14
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Abstract
Combination antiretroviral therapy (ART) suppresses human immunodeficiency virus (HIV) replication and improves immune function, but is unable to eradicate the virus. Therefore, development of an HIV cure has become one of the main priorities of the HIV research field. The main obstacle for an HIV cure is the formation of latent viral reservoirs, where the virus is able to “hide” despite decades of therapy, just to reignite active replication once therapy is stopped. Revealing HIV hiding places is thus central to HIV cure research, but the absence of markers of these reservoir cells greatly complicates the search for a cure. Identification of one or several marker(s) of latently infected cells would represent a significant step forward toward a better description of the cell types involved and improved understanding of HIV latency. Moreover, it could provide a “handle” for selective therapeutic targeting of the reservoirs. A number of cellular markers of HIV reservoir have recently been proposed, including immune checkpoint molecules, CD2, and CD30. CD32a is perhaps the most promising of HIV reservoir markers as it is reported to be associated with a very prominent enrichment in HIV DNA, although this finding has been challenged. In this review, we provide an update on the current knowledge about HIV reservoir markers. We specifically highlight studies that characterized markers of persistently infected cells in the lymphoid tissues.
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Affiliation(s)
- Gilles Darcis
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Infectious Diseases Department, Liège University Hospital, Liège, Belgium
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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15
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Abstract
Antiretroviral therapy (ART) can effectively suppress ongoing HIV replication and block disease progression, but the infection is never cured due to the persistence of a small pool of latently infected cells hosting integrated replication-competent HIV proviruses. However, the vast majority of HIV proviruses in ART-treated patients are replication-incompetent due to a variety of genetic defects. Most defective proviruses (around 90%) contain large internal deletions or are G-to-A hypermutated, resulting in destruction of most if not all viral open reading frames, which is consistent with the idea that cytotoxic T cells (CTLs) effectively remove cells that produce viral antigens. An intriguing subclass of defective proviruses (around 10%) that are consistently detected in such patients carry a small deletion or a point mutation in a relatively precise and well conserved region near the 5ʹ end of the HIV genome, in the area that encodes the major splice donor (MSD) site and the packaging signal Ѱ in the viral RNA genome. Why this subclass of proviruses is defective has never been properly understood. We now propose a mechanistic scenario for how these MSD-Ѱ mutations can prevent viral protein expression. Based on ample results in literature, we argue that MSD inactivation triggers the activity of the 5ʹ-polyadenylation site, resulting in the production of ultra-short non-protein-coding HIV transcripts.
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Affiliation(s)
- Atze T Das
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands. .,Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.
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16
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van Montfort T, van der Sluis R, Darcis G, Beaty D, Groen K, Pasternak AO, Pollakis G, Vink M, Westerhout EM, Hamdi M, Bakker M, van der Putten B, Jurriaans S, Prins JH, Jeeninga R, Thomas AAM, Speijer D, Berkhout B. Dendritic cells potently purge latent HIV-1 beyond TCR-stimulation, activating the PI3K-Akt-mTOR pathway. EBioMedicine 2019; 42:97-108. [PMID: 30824386 PMCID: PMC6491380 DOI: 10.1016/j.ebiom.2019.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 02/06/2023] Open
Abstract
Background The latent HIV-1 reservoir in treated patients primarily consists of resting memory CD4+ T cells. Stimulating the T-cell receptor (TCR), which facilitates transition of resting into effector T cells, is the most effective strategy to purge these latently infected cells. Here we supply evidence that TCR-stimulated effector T cells still frequently harbor latent HIV-1. Methods Primary HIV-1 infected cells were used in a latency assay with or without dendritic cells (DCs) and reversion of HIV-1 latency was determined, in the presence or absence of specific pathway inhibitors. Findings Renewed TCR-stimulation or subsequent activation with latency reversing agents (LRAs) did not overcome latency. However, interaction of infected effector cells with DCs triggered further activation of latent HIV-1. When compared to TCR-stimulation only, CD4+ T cells from aviremic patients receiving TCR + DC-stimulation reversed latency more frequently. Such a “one-two punch” strategy seems ideal for purging the reservoir. We determined that DC contact activates the PI3K-Akt-mTOR pathway in CD4+ T cells. Interpretation This insight could facilitate the development of a novel class of potent LRAs that purge latent HIV beyond levels reached by T-cell activation.
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Affiliation(s)
- Thijs van Montfort
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands.
| | - Renée van der Sluis
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Gilles Darcis
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands; Department of Infectious Diseases, Liege University Hospital, Liege, Belgium
| | - Doyle Beaty
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Kevin Groen
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Alexander O Pasternak
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Georgios Pollakis
- Department of Clinical Infection, Microbiology and Immunology (CIMI), University of Liverpool, Liverpool, 8 West Derby Street, United Kingdom
| | - Monique Vink
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Ellen M Westerhout
- Department of Oncogenomics, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Mohamed Hamdi
- Department of Oncogenomics, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Margreet Bakker
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Boas van der Putten
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Suzanne Jurriaans
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Jan H Prins
- Department of Internal Medicine, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Rienk Jeeninga
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Adri A M Thomas
- Department Developmental Biology, Faculty Beta-Science, Utrecht, Padualaan 8, 3584, CH, the Netherlands
| | - Dave Speijer
- Department of Medical Biochemistry, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
| | - Ben Berkhout
- Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam University Medical Centers, Amsterdam, Meibergdreef 15, 1105AZ, the Netherlands
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17
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Abstract
Cell-associated (CA) HIV RNA has received much attention in recent years as a surrogate measure of the efficiency of HIV latency reversion and because it may provide an estimate of the viral reservoir size. This review provides an update on some recent insights in the biology and clinical utility of this biomarker. We discuss a number of important considerations to be taken into account when interpreting CA HIV RNA measurements, as well as different methods to measure this biomarker.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands.
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands
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18
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Abstract
HIV forms a reservoir that persists despite prolonged therapy and is considered the main barrier to an HIV cure. Baxter et al. (2016) in this issue of Cell Host & Microbe and Boritz et al. (2016) in a recent Cell paper shed new light on HIV persistence in infected individuals.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, the Netherlands.
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, the Netherlands
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19
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Mann J, Pasternak AO, Chahroudi A, Singh JA, Ross AL. The latest science from the IAS Towards an HIV Cure Symposium: 16-17 July 2016, Durban, South Africa. J Virus Erad 2016; 2:235-241. [PMID: 27781107 PMCID: PMC5075352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Jaclyn Mann
- HIV Pathogenesis Programme,
University of KwaZulu-Natal,
Durban,
South Africa
| | - Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology,
Academic Medical Center of the University of Amsterdam,
the Netherlands
| | - Ann Chahroudi
- Department of Pediatrics, Emory University School of Medicine,
Atlanta,
Georgia,
USA
| | | | - Anna Laura Ross
- International and Scientific Relations, ANRS,
Paris,
France,Corresponding author: Anna Laura Ross,
International and Scientific Relations, ANRS,
101 rue de Tolbiac,
75013Paris,
France
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20
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Pasternak AO, de Bruin M, Bakker M, Berkhout B, Prins JM. High Current CD4+ T Cell Count Predicts Suboptimal Adherence to Antiretroviral Therapy. PLoS One 2015; 10:e0140791. [PMID: 26468956 PMCID: PMC4607457 DOI: 10.1371/journal.pone.0140791] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 09/30/2015] [Indexed: 11/18/2022] Open
Abstract
High levels of adherence to antiretroviral therapy (ART) are necessary for achieving and maintaining optimal virological suppression, as suboptimal adherence leads to therapy failure and disease progression. It is well known that adherence to ART predicts therapy response, but it is unclear whether clinical outcomes of ART predict adherence. To examine the predictive power of current CD4+ T cell count for adherence of HIV-infected individuals to ART, we performed a cross-sectional analysis of 133 Dutch HIV patients with electronically measured adherence. In a multivariate analysis adjusting for a number of sociodemographic and clinical variables, high current CD4+ T cell count (>660 cells/mm3) was most strongly associated with lower adherence to ART (assessed as a continuous variable) during a two-month period immediately following the measurements of variables (P = 0.008). The twice-per-day (versus once-per-day) dosing regimen was also significantly associated with lower adherence (P = 0.014). In a second multivariate analysis aimed at determining the predictors of suboptimal (<100% of the doses taken) adherence, high current CD4+ T cell count was again the strongest independent predictor of suboptimal adherence to ART (P = 0.015), and the twice-per-day dosing regimen remained associated with suboptimal adherence (P = 0.025). The association between suboptimal adherence and virological suppression was significant in patients with high CD4+ T cell counts, but not in patients with low or intermediate CD4+ T cell counts (P = 0.036 and P = 0.52, respectively; P = 0.047 for comparison of the effects of adherence on virological suppression between patients with high vs. low or intermediate CD4+ T cell counts), suggesting that apart from promoting suboptimal adherence, high CD4+ T cell count also strengthens the effect of adherence on virological suppression. Therefore, sustained efforts to emphasize continued adherence are necessary, especially for patients with high CD4+ T cell counts.
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Affiliation(s)
- Alexander O. Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
| | - Marijn de Bruin
- Health Psychology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Margreet Bakker
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Jan M. Prins
- Department of Internal Medicine, Division of Infectious Diseases, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
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21
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Kiselinova M, Pasternak AO, De Spiegelaere W, Vogelaers D, Berkhout B, Vandekerckhove L. Comparison of droplet digital PCR and seminested real-time PCR for quantification of cell-associated HIV-1 RNA. PLoS One 2014; 9:e85999. [PMID: 24465831 PMCID: PMC3897572 DOI: 10.1371/journal.pone.0085999] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 12/03/2013] [Indexed: 11/19/2022] Open
Abstract
Cell-associated (CA) HIV-1 RNA is considered a potential marker for assessment of viral reservoir dynamics and antiretroviral therapy (ART) response in HIV-infected patients. Recent studies employed sensitive seminested real-time quantitative (q)PCR to quantify CA HIV-1 RNA. Digital PCR has been recently described as an alternative PCR-based technique for absolute quantification with higher accuracy compared to qPCR. Here, a comparison was made between the droplet digital PCR (ddPCR) and the seminested qPCR for quantification of unspliced (us) and multiply spliced (ms) CA HIV-1 RNA. Synthetic RNA standards and CA HIV-1 RNA from infected patients on and off ART (N = 34) were quantified with both methods. Correlations were observed between the methods both for serially diluted synthetic standards (usRNA: R2 = 0.97, msRNA: R2 = 0.92) and patient-derived samples (usRNA: R2 = 0.51, msRNA: R2 = 0.87). Seminested qPCR showed better quantitative linearity, accuracy and sensitivity in the quantification of synthetic standards than ddPCR, especially in the lower quantification ranges. Both methods demonstrated equally high detection rate of usRNA in patient samples on and off ART (91%), whereas ddPCR detected msRNA in larger proportion of samples from ART-treated patients (p = 0.13). We observed an average agreement between the methods for usRNA quantification in patient samples, albeit with a large standard deviation (bias = 0.05±0.75 log10). However, a bias of 0.94±0.36 log10 was observed for msRNA. No-template controls were consistently negative in the seminested qPCR, but yielded a positive ddPCR signal for some wells. Therefore, the false positive signals may have affected the detection power of ddPCR in this study. Digital PCR is promising for HIV nucleic acid quantification, but the false positive signals need further attention. Quantitative assays for CA HIV RNA have the potential to improve monitoring of patients on ART and to be used in clinical studies aimed at HIV eradication, but should be cross-validated by multiple laboratories prior to wider use.
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Affiliation(s)
- Maja Kiselinova
- HIV Translational Research Unit (HTRU), Department of Internal Medicine, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Alexander O. Pasternak
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Ward De Spiegelaere
- HIV Translational Research Unit (HTRU), Department of Internal Medicine, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Dirk Vogelaers
- HIV Translational Research Unit (HTRU), Department of Internal Medicine, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Ben Berkhout
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Linos Vandekerckhove
- HIV Translational Research Unit (HTRU), Department of Internal Medicine, Ghent University and Ghent University Hospital, Ghent, Belgium
- * E-mail:
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22
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van der Kuyl AC, Bakker M, Jurriaans S, Back NKT, Pasternak AO, Cornelissen M, Berkhout B. Translational HIV-1 research: from routine diagnostics to new virology insights in Amsterdam, the Netherlands during 1983-2013. Retrovirology 2013; 10:93. [PMID: 23985078 PMCID: PMC3765835 DOI: 10.1186/1742-4690-10-93] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/21/2013] [Indexed: 02/07/2023] Open
Abstract
An HIV-1 diagnostic laboratory was established in the Academic Medical Center (AMC) of the University of Amsterdam after the discovery of human immunodeficiency virus (HIV) as the cause of the acquired immunodeficiency syndrome (AIDS). The first AIDS patients were diagnosed here in 1981 and since 1983 we have tested the samples of 50992 patients using a variety of assays that greatly improved over the years. We will describe some of the basic results from this diagnostic laboratory and then focus on the spin-off in terms of the development of novel virus assays to detect super-infections and ultra-sensitive assays to measure the intracellular HIV-1 RNA load. We also review several original research findings in the field of HIV-1 virology that stem from initial observations made in the diagnostic unit. This includes the study of genetic defects in the HIV-1 genome and time trends of the replication fitness over 30 years of viral evolution, but also the description of novel HIV-1 variants in difficult-to-diagnose clinical specimen.
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Affiliation(s)
- Antoinette C van der Kuyl
- Laboratory of Experimental Virology, Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands.
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23
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Pasternak AO, Lukashov VV, Berkhout B. Cell-associated HIV RNA: a dynamic biomarker of viral persistence. Retrovirology 2013; 10:41. [PMID: 23587031 PMCID: PMC3637491 DOI: 10.1186/1742-4690-10-41] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 04/10/2013] [Indexed: 12/27/2022] Open
Abstract
In most HIV-infected individuals adherent to modern antiretroviral therapy (ART), plasma viremia stays undetectable by clinical assays and therefore, additional virological markers for monitoring and predicting therapy responses and for measuring the degree of HIV persistence in patients on ART should be identified. For the above purposes, quantitation of cell-associated HIV biomarkers could provide a useful alternative to measurements of viral RNA in plasma. This review concentrates on cell-associated (CA) HIV RNA with the emphasis on its use as a virological biomarker. We discuss the significance of CA HIV RNA as a prognostic marker of disease progression in untreated patients and as an indicator of residual virus replication and the size of the dynamic viral reservoir in ART-treated patients. Potential value of this biomarker for monitoring the response to ART and to novel HIV eradication therapies is highlighted.
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Affiliation(s)
- Alexander O Pasternak
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam-CINIMA, Academic Medical Center, University of Amsterdam, Meibergdreef 15, Amsterdam 1105 AZ, The Netherlands.
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24
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Pasternak AO, de Bruin M, Jurriaans S, Bakker M, Berkhout B, Prins JM, Lukashov VV. Modest nonadherence to antiretroviral therapy promotes residual HIV-1 replication in the absence of virological rebound in plasma. J Infect Dis 2012; 206:1443-52. [PMID: 22927449 DOI: 10.1093/infdis/jis502] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Modern antiretroviral therapy (ART) regimens are widely assumed to forgive modest nonadherence, because virological suppression in plasma is common at adherence levels of >70%. Yet, it is unknown whether human immunodeficiency virus type 1 (HIV-1) replication is completely suppressed at these levels of adherence. METHODS We longitudinally quantified levels of cell-associated HIV-1 RNA and DNA in 40 patients (median duration of successful ART before study initiation, 46 months), whose 1-week adherence to therapy prior to the sampling moments was measured electronically. RESULTS Patients were constantly 100% adherent (the optimal-adherence group), demonstrated improving adherence over time (the improving-adherence group), or neither of the above (the poor-adherence group). Adherence never decreased to <70% in any patient, and no rebound in plasma virological levels was observed. Nevertheless, poor adherence but not optimal or improving adherence caused a significant longitudinal increase in cell-associated HIV RNA levels (P = .006). Time-weighted changes and regression slopes of viral RNA load for the poor-adherence group were significantly higher than those for the optimal-adherence group (P < .01). CONCLUSIONS Because ART only blocks infection of new cells but not viral RNA transcription in cells infected before therapy initiation, the observed effects strongly suggest that modest nonadherence can cause new cycles of HIV-1 replication that are undetectable by commercial plasma viral load assays.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam, the Netherlands
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25
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Cornelissen M, Pasternak AO, Grijsen ML, Zorgdrager F, Bakker M, Blom P, Prins JM, Jurriaans S, van der Kuyl AC. HIV-1 dual infection is associated with faster CD4+ T-cell decline in a cohort of men with primary HIV infection. Clin Infect Dis 2011; 54:539-47. [PMID: 22157174 DOI: 10.1093/cid/cir849] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In vitro, animal, and mathematical models suggest that human immunodeficiency virus (HIV) co- or superinfection would result in increased fitness of the pathogen and, possibly, increased virulence. However, in patients, the impact of dual HIV type 1 (HIV-1) infection on disease progression is unclear, because parameters relevant for disease progression have not been strictly analyzed. The objective of the present study is to analyze the effect of dual HIV-1 infections on disease progression in a well-defined cohort of men who have sex with men. METHODS Between 2000 and 2009, 37 men who had primary infection with HIV-1 subtype B, no indication for immediate need of combination antiretroviral therapy (cART), and sufficient follow-up were characterized with regard to dual infection or single infection and to coreceptor use. Patients were followed to estimate the effect of these parameters on clinical disease progression, as defined by the rate of CD4(+) T-cell decline and the time to initiation of cART. RESULTS Four patients presented with HIV-1 coinfection; 6 patients acquired HIV-1 superinfection, on average 8.5 months from their primary infection; and 27 patients remained infected with a single strain. Slopes of longitudinal CD4(+) T-cell counts and time-weighted changes from baseline were significantly steeper for patients with dual infection compared with patients with single infection. Multivariate analysis showed that the most important parameter associated with CD4(+) T-cell decline over time was dual infection (P = .001). Additionally, patients with HIV-1 coinfection had a significantly earlier start of cART (P < .0001). CONCLUSIONS Dual HIV-1 infection is the main factor associated with CD4(+) T-cell decline in men who have untreated primary infection with HIV-1 subtype B.
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Affiliation(s)
- Marion Cornelissen
- Laboratory of Experimental Virology, Academic Medical Center, University of Amsterdam, Netherlands
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Cornelissen M, Pasternak AO, Grijsen ML, Zorgdrager F, Bakker M, Blom P, Prins JM, Jurriaans S, van der Kuyl AC. HIV-1 dual infection is associated with faster CD4+T cell decline in a cohort of men with primary HIV infection. Retrovirology 2011. [PMCID: PMC3236900 DOI: 10.1186/1742-4690-8-s2-p14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Pasternak AO, de Bruin M, Jurriaans S, Bakker M, Berkhout B, Prins JM, Lukashov VV. Modest deviations from optimal adherence to antiretroviral therapy promote residual HIV-1 replication in the absence of virological rebound in plasma. Retrovirology 2011. [PMCID: PMC3236881 DOI: 10.1186/1742-4690-8-s2-o35] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Giliazova AV, Zenin PV, Pronin AI, Serkov IL, Khametova KM, Orlova-Morozova EA, Zhukova EV, Kornilaeva GV, Pasternak AO, Lukashov VV, Karamov EV. [Molecular epidemiology of HIV-1 strains in the Moscow Region]. Vopr Virusol 2010; 55:25-29. [PMID: 21260992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Moscow Region is one of the HIV-1-affected subjects of the Russian Federation; there were 34613 HIV-1-infected subjects as of October 31, 2009. To characterize the molecular epidemiology of HIV-1 in the Moscow Region, the investigators obtained and studied HIV-1 variants from 61 infected subjects of the region, who were major risk groups: intravenous drug users (IDUs) and hetero- and homosexually infected persons. Genetic analysis of HIV-1 variants was carried out by sequencing the gag genes (729 nucleotides in length, including full-length protein p17 and partial p24) andlor env (270 nucleotides in length, V3 region) with further phylogenetic analysis. The findings demonstrated that HIV-1 subtype A variants are dominant in the Moscow Region and detectable in 93.5% of IDUs and 100% of heterosexually infected persons. Phylogenetically (and accordingly epidemiologically) unrelated HIV-1 subtype B strains were revealed in 4 patients, including 2 IDUs.
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Pasternak AO, Jurriaans S, Bakker M, Berkhout B, Lukashov VV. Steady increase in cellular HIV-1 load during the asymptomatic phase of untreated infection despite stable plasma viremia. AIDS 2010; 24:1641-9. [PMID: 20543660 DOI: 10.1097/qad.0b013e32833b3171] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE To compare the dynamics of HIV-1 molecular markers in peripheral blood mononuclear cells (PBMCs) and in plasma during the asymptomatic phase of untreated HIV-1 infection. DESIGN AND METHODS Using seminested real-time PCR assays, we measured the levels of HIV-1 proviral (pr) DNA, unspliced (us) RNA, and multiply spliced RNA in the PBMCs of 10 untreated HIV-1-infected men at multiple time points during the asymptomatic phase of infection and compared the longitudinal trends of these markers with those of viral RNA in plasma. RESULTS Whereas plasma RNA levels did not significantly change in any of the individuals, levels of usRNA significantly increased with time in six out of 10 persons, and levels of prDNA in four. Slopes, changes, and time-weighted changes from baseline of usRNA, prDNA, and CD4 cell count, but not of plasma RNA, were significantly different from zero (P < 0.01). No significant longitudinal trend of plasma RNA was observed in the study group using linear mixed models, whereas the trends of usRNA, prDNA, and CD4 cell count were highly significant (P < 0.001). usRNA levels increased significantly faster than those of plasma RNA or prDNA, suggesting a temporal increase in viral replication rates in PBMCs. Finally, CD4 cell count inversely correlated with levels of usRNA and prDNA, but not with plasma RNA level. CONCLUSION During the asymptomatic phase of untreated HIV-1 infection, when virion production and clearance are balanced, resulting in stable plasma viremia, viral load in PBMCs steadily increases and is a sensitive and direct longitudinal virological marker of infection progression.
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Pasternak AO, Jurriaans S, Bakker M, Prins JM, Berkhout B, Lukashov VV. Cellular levels of HIV unspliced RNA from patients on combination antiretroviral therapy with undetectable plasma viremia predict the therapy outcome. PLoS One 2009; 4:e8490. [PMID: 20046870 PMCID: PMC2795168 DOI: 10.1371/journal.pone.0008490] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Accepted: 12/03/2009] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Combination antiretroviral therapy (cART), the standard of care for HIV-1 infection, is considered to be successful when plasma viremia remains below the detection limit of commercial assays. Yet, cART fails in a substantial proportion of patients after the apparent success. No laboratory markers are known that are predictive of cART outcome in initial responders during the period of undetectable plasma viremia. METHODOLOGY/PRINCIPAL FINDINGS Here, we report the results of a retrospective longitudinal study of twenty-six HIV-infected individuals who initially responded to cART by having plasma viremia suppressed to <50 copies/ml. Eleven of these patients remained virologically suppressed, whereas fifteen experienced subsequent cART failure. Using sensitive methods based on seminested real-time PCR, we measured the levels of HIV-1 proviral (pr) DNA, unspliced (us) RNA, and multiply spliced RNA in the peripheral blood mononuclear cells (PBMC) of these patients at multiple time points during the period of undetectable plasma viremia on cART. Median under-therapy level of usRNA was significantly higher (0.43 log(10) difference, P = 0.0015) in patients who experienced subsequent cART failure than in successfully treated patients. In multivariate analysis, adjusted for baseline CD4(+) counts, prior ART experience, and particular cART regimens, the maximal usRNA level under therapy was the best independent predictor of subsequent therapy failure (adjusted odds ratio [95% CI], 24.4 [1.5-389.5], P = 0.024). The only other factor significantly associated with cART failure was prior ART experience (adjusted odds ratio [95% CI], 12.3 [1.1-138.4], P = 0.042). Levels of usRNA under cART inversely correlated with baseline CD4(+) counts (P = 0.0003), but did not correlate with either baseline usRNA levels or levels of prDNA under therapy. CONCLUSION Our data demonstrate that the level of HIV-1 usRNA in PBMC, measured in cART-treated patients with undetectable plasma viremia, is a strong predictive marker for the outcome of therapy.
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Affiliation(s)
- Alexander O. Pasternak
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Suzanne Jurriaans
- Department of Medical Microbiology, Laboratory of Clinical Virology, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Margreet Bakker
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Jan M. Prins
- Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Ben Berkhout
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
| | - Vladimir V. Lukashov
- Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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Abstract
Many positive-stranded RNA viruses use subgenomic mRNAs to express part of their genetic information. To produce structural and accessory proteins, members of the order Nidovirales (corona-, toro-, arteri- and roniviruses) generate a 3' co-terminal nested set of at least three and often seven to nine mRNAs. Coronavirus and arterivirus subgenomic transcripts are not only 3' co-terminal but also contain a common 5' leader sequence, which is derived from the genomic 5' end. Their synthesis involves a process of discontinuous RNA synthesis that resembles similarity-assisted RNA recombination. Most models proposed over the past 25 years assume co-transcriptional fusion of subgenomic RNA leader and body sequences, but there has been controversy over the question of whether this occurs during plus- or minus-strand synthesis. In the latter model, which has now gained considerable support, subgenomic mRNA synthesis takes place from a complementary set of subgenome-size minus-strand RNAs, produced by discontinuous minus-strand synthesis. Sense-antisense base-pairing interactions between short conserved sequences play a key regulatory role in this process. In view of the presumed common ancestry of nidoviruses, the recent finding that ronivirus and torovirus mRNAs do not contain a common 5' leader sequence is surprising. Apparently, major mechanistic differences must exist between nidoviruses, which raises questions about the functions of the common leader sequence and nidovirus transcriptase proteins and the evolution of nidovirus transcription. In this review, nidovirus transcription mechanisms are compared, the experimental systems used are critically assessed and, in particular, the impact of recently developed reverse genetic systems is discussed.
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Affiliation(s)
- Alexander O Pasternak
- Molecular Virology Laboratory, Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, LUMC P4-26, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Willy J M Spaan
- Molecular Virology Laboratory, Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, LUMC P4-26, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Eric J Snijder
- Molecular Virology Laboratory, Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, LUMC P4-26, PO Box 9600, 2300 RC Leiden, The Netherlands
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Abstract
The subgenomic (sg) mRNAs of arteriviruses (order Nidovirales) form a 5'- and 3'-coterminal nested set with the viral genome. Their 5' common leader sequence is derived from the genomic 5'-proximal region. Fusion of sg RNA leader and "body" segments involves a discontinuous transcription step. Presumably during minus-strand synthesis, the nascent RNA strand is transferred from one site in the genomic template to another, a process guided by conserved transcription-regulating sequences (TRSs) at these template sites. Subgenomic RNA species are produced in different but constant molar ratios, with the smallest RNAs usually being most abundant. Factors thought to influence sg RNA synthesis are size differences between sg RNA species, differences in sequence context between body TRSs, and the mutual influence (or competition) between strand transfer reactions occurring at different body TRSs. Using an Equine arteritis virus infectious cDNA clone, we investigated how body TRS activity affected sg RNA synthesis from neighboring body TRSs. Flanking sequences were standardized by head-to-tail insertion of several copies of an RNA7 body TRS cassette. A perfect gradient of sg RNA abundance, progressively favoring smaller RNA species, was observed. Disruption of body TRS function by mutagenesis did not have a significant effect on the activity of other TRSs. However, deletion of body TRS-containing regions enhanced synthesis of sg RNAs from upstream TRSs but not of those produced from downstream TRSs. The results of this study provide considerable support for the proposed discontinuous extension of minus-strand RNA synthesis as a crucial step in sg RNA synthesis.
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Affiliation(s)
- Alexander O Pasternak
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
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Pasternak AO, van den Born E, Spaan WJM, Snijder EJ. The stability of the duplex between sense and antisense transcription-regulating sequences is a crucial factor in arterivirus subgenomic mRNA synthesis. J Virol 2003; 77:1175-83. [PMID: 12502834 PMCID: PMC140805 DOI: 10.1128/jvi.77.2.1175-1183.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2002] [Accepted: 10/07/2002] [Indexed: 11/20/2022] Open
Abstract
Subgenomic mRNAs of nidoviruses (arteriviruses and coronaviruses) are composed of a common leader sequence and a "body" part of variable size, which are derived from the 5'- and 3'-proximal part of the genome, respectively. Leader-to-body joining has been proposed to occur during minus-strand RNA synthesis and to involve transfer of the nascent RNA strand from one site in the template to another. This discontinuous step in subgenomic RNA synthesis is guided by short transcription-regulating sequences (TRSs) that are present at both these template sites (leader TRS and body TRS). Sense-antisense base pairing between the leader TRS in the plus strand and the body TRS complement in the minus strand is crucial for strand transfer. Here we show that extending the leader TRS-body TRS duplex beyond its wild-type length dramatically enhanced the subgenomic mRNA synthesis of the arterivirus Equine arteritis virus (EAV). Generally, the relative amount of a subgenomic mRNA correlated with the calculated stability of the corresponding leader TRS-body TRS duplex. In addition, various leader TRS mutations induced the generation of minor subgenomic RNA species that were not detected upon infection with wild-type EAV. The synthesis of these RNA species involved leader-body junction events at sites that bear only limited resemblance to the canonical TRS. However, with the mutant leader TRS, but not with the wild-type leader TRS, these sequences could form a duplex that was stable enough to direct subgenomic RNA synthesis, again demonstrating that the stability of the leader TRS-body TRS duplex is a crucial factor in arterivirus subgenomic mRNA synthesis.
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Affiliation(s)
- Alexander O Pasternak
- Molecular Virology Laboratory, Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, The Netherlands
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Pasternak AO, van den Born E, Spaan WJ, Snijder EJ. Sequence requirements for RNA strand transfer during nidovirus discontinuous subgenomic RNA synthesis. EMBO J 2001; 20:7220-8. [PMID: 11742998 PMCID: PMC125340 DOI: 10.1093/emboj/20.24.7220] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2001] [Revised: 10/25/2001] [Accepted: 11/01/2001] [Indexed: 12/02/2022] Open
Abstract
Nidovirus subgenomic mRNAs contain a leader sequence derived from the 5' end of the genome fused to different sequences ('bodies') derived from the 3' end. Their generation involves a unique mechanism of discontinuous subgenomic RNA synthesis that resembles copy-choice RNA recombination. During this process, the nascent RNA strand is transferred from one site in the template to another, during either plus or minus strand synthesis, to yield subgenomic RNA molecules. Central to this process are transcription-regulating sequences (TRSs), which are present at both template sites and ensure the fidelity of strand transfer. Here we present results of a comprehensive co-variation mutagenesis study of equine arteritis virus TRSs, demonstrating that discontinuous RNA synthesis depends not only on base pairing between sense leader TRS and antisense body TRS, but also on the primary sequence of the body TRS. While the leader TRS merely plays a targeting role for strand transfer, the body TRS fulfils multiple functions. The sequences of mRNA leader-body junctions of TRS mutants strongly suggested that the discontinuous step occurs during minus strand synthesis.
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Affiliation(s)
| | | | | | - Eric J. Snijder
- Molecular Virology Laboratory, Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
Corresponding author e-mail: A.O.Pasternak and E.van den Born contributed equally to this work
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Pasternak AO, Gultyaev AP, Spaan WJ, Snijder EJ. Genetic manipulation of arterivirus alternative mRNA leader-body junction sites reveals tight regulation of structural protein expression. J Virol 2000; 74:11642-53. [PMID: 11090163 PMCID: PMC112446 DOI: 10.1128/jvi.74.24.11642-11653.2000] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2000] [Accepted: 09/25/2000] [Indexed: 11/20/2022] Open
Abstract
To express its structural proteins, the arterivirus Equine arteritis virus (EAV) produces a nested set of six subgenomic (sg) RNA species. These RNA molecules are generated by a mechanism of discontinuous transcription, during which a common leader sequence, representing the 5' end of the genomic RNA, is attached to the bodies of the sg RNAs. The connection between the leader and body parts of an mRNA is formed by a short, conserved sequence element termed the transcription-regulating sequence (TRS), which is present at the 3' end of the leader as well as upstream of each of the structural protein genes. With the exception of RNA3, only one body TRS was previously assumed to be used to join the leader and body of each EAV sg RNA. Here we show that for the synthesis of two other sg RNAs, RNA4 and RNA5, alternative leader-body junction sites that differ substantially in transcriptional activity are used. By site-directed mutagenesis of an EAV infectious cDNA clone, the alternative TRSs used to generate RNA3, -4, and -5 were inactivated, which strongly influenced the corresponding RNA levels and the production of infectious progeny virus. The relative amounts of RNA produced from alternative TRSs differed significantly and corresponded to the relative infectivities of the virus mutants. This strongly suggested that the structural proteins that are expressed from these RNAs are limiting factors during the viral life cycle and that the discontinuous step in sg RNA synthesis is crucial for the regulation of their expression. On the basis of a theoretical analysis of the predicted RNA structure of the 3' end of the EAV genome, we propose that the local secondary RNA structure of the body TRS regions is an important factor in the regulation of the discontinuous step in EAV sg mRNA synthesis.
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Affiliation(s)
- A O Pasternak
- Department of Virology, Center of Infectious Diseases, Leiden University Medical Center, Leiden University, Leiden, The Netherlands
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