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Emery A, Joseph SB, Swanstrom R. Nonsuppressible viremia during HIV-1 therapy meets molecular virology. J Clin Invest 2023; 133:167925. [PMID: 36919694 PMCID: PMC10014097 DOI: 10.1172/jci167925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
HIV-1 replication can be suppressed with antiretroviral therapy (ART), but individuals who stop taking ART soon become viremic again. Some people experience extended times of detectable viremia despite optimal adherence to ART. In this issue of the JCI, White, Wu, and coauthors elucidate a source of nonsuppressible viremia (NSV) in treatment-adherent patients - clonally expanded T cells harboring HIV-1 proviruses with small deletions or mutations in the 5'-leader, the UTR that includes the major splice donor site of viral RNA. These mutations altered viral RNA-splicing efficiency and RNA dimerization and packaging, yet still allowed production of detectable levels of noninfectious virus particles. These particles lacked the HIV-1 Env surface protein required for cell entry and failed to form the mature capsid cone required for infectivity. These studies improve our understanding of NSV and the regulation of viral functions in the 5'-leader with implications for rationalized care in individuals with NSV.
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Affiliation(s)
- Ann Emery
- Lineberger Comprehensive Cancer Center
| | - Sarah B Joseph
- Lineberger Comprehensive Cancer Center.,Department of Microbiology and Immunology.,UNC HIV Cure Center, and
| | - Ronald Swanstrom
- Lineberger Comprehensive Cancer Center.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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White JA, Wu F, Yasin S, Moskovljevic M, Varriale J, Dragoni F, Camilo-Contreras A, Duan J, Zheng MY, Tadzong NF, Patel HB, Quiambao JMC, Rhodehouse K, Zhang H, Lai J, Beg SA, Delannoy M, Kilcrease C, Hoffmann CJ, Poulin S, Chano F, Tremblay C, Cherian J, Barditch-Crovo P, Chida N, Moore RD, Summers MF, Siliciano RF, Siliciano JD, Simonetti FR. Clonally expanded HIV-1 proviruses with 5'-leader defects can give rise to nonsuppressible residual viremia. J Clin Invest 2023; 133:165245. [PMID: 36602866 PMCID: PMC10014112 DOI: 10.1172/jci165245] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/04/2023] [Indexed: 01/06/2023] Open
Abstract
BackgroundAntiretroviral therapy (ART) halts HIV-1 replication, decreasing viremia to below the detection limit of clinical assays. However, some individuals experience persistent nonsuppressible viremia (NSV) originating from CD4+ T cell clones carrying infectious proviruses. Defective proviruses represent over 90% of all proviruses persisting during ART and can express viral genes, but whether they can cause NSV and complicate ART management is unknown.MethodsWe undertook an in-depth characterization of proviruses causing NSV in 4 study participants with optimal adherence and no drug resistance. We investigated the impact of the observed defects on 5'-leader RNA properties, virus infectivity, and gene expression. Integration-site specific assays were used to track these proviruses over time and among cell subsets.ResultsClones carrying proviruses with 5'-leader defects can cause persistent NSV up to approximately 103 copies/mL. These proviruses had small, often identical deletions or point mutations involving the major splicing donor (MSD) site and showed partially reduced RNA dimerization and nucleocapsid binding. Nevertheless, they were inducible and produced noninfectious virions containing viral RNA, but lacking envelope.ConclusionThese findings show that proviruses with 5'-leader defects in CD4+ T cell clones can give rise to NSV, affecting clinical care. Sequencing of the 5'-leader can help in understanding failure to completely suppress viremia.FundingOffice of the NIH Director and National Institute of Dental and Craniofacial Research, NIH; Howard Hughes Medical Institute; Johns Hopkins University Center for AIDS Research; National Institute for Allergy and Infectious Diseases (NIAID), NIH, to the PAVE, BEAT-HIV, and DARE Martin Delaney collaboratories.
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Affiliation(s)
- Jennifer A White
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Fengting Wu
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Saif Yasin
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Milica Moskovljevic
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Joseph Varriale
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Filippo Dragoni
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - Jiayi Duan
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mei Y Zheng
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Ndeh F Tadzong
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Heer B Patel
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Jeanelle Mae C Quiambao
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA
| | - Kyle Rhodehouse
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hao Zhang
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Jun Lai
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Subul A Beg
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael Delannoy
- Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christin Kilcrease
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christopher J Hoffmann
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | | | - Cécile Tremblay
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, Canada.,Département de Microbiologie, Immunologie et Infectiologie, Université de Montréal, Montreal, Canada
| | - Jerald Cherian
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Patricia Barditch-Crovo
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Natasha Chida
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Richard D Moore
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael F Summers
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland, USA.,Howard Hughes Medical Institute, Baltimore, Maryland, USA
| | - Robert F Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Howard Hughes Medical Institute, Baltimore, Maryland, USA
| | - Janet D Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Francesco R Simonetti
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Kincer LP, Joseph SB, Gilleece MM, Hauser BM, Sizemore S, Zhou S, Di Germanio C, Zetterberg H, Fuchs D, Deeks SG, Spudich S, Gisslen M, Price RW, Swanstrom R. Rebound HIV-1 in cerebrospinal fluid after antiviral therapy interruption is mainly clonally amplified R5 T cell-tropic virus. Nat Microbiol 2023; 8:260-271. [PMID: 36717718 PMCID: PMC10201410 DOI: 10.1038/s41564-022-01306-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 12/14/2022] [Indexed: 02/01/2023]
Abstract
HIV-1 persists as a latent reservoir in people receiving suppressive antiretroviral therapy (ART). When ART is interrupted (treatment interruption/TI), rebound virus re-initiates systemic infection in the lymphoid system. During TI, HIV-1 is also detected in cerebrospinal fluid (CSF), although the source of this rebound virus is unknown. To investigate whether there is a distinct HIV-1 reservoir in the central nervous system (CNS), we compared rebound virus after TI in the blood and CSF of 11 participants. Peak rebound CSF viral loads vary and we show that high viral loads and the appearance of clonally amplified viral lineages in the CSF are correlated with the transient influx of white blood cells. We found no evidence of rebound macrophage-tropic virus in the CSF, even in one individual who had macrophage-tropic HIV-1 in the CSF pre-therapy. We propose a model in which R5 T cell-tropic virus is released from infected T cells that enter the CNS from the blood (or are resident in the CNS during therapy), with clonal amplification of infected T cells and virus replication occurring in the CNS during TI.
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Affiliation(s)
- Laura P Kincer
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sarah Beth Joseph
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- UNC HIV Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Maria M Gilleece
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biogen, Research Triangle Park, NC, USA
| | - Blake M Hauser
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Sabrina Sizemore
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shuntai Zhou
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Clara Di Germanio
- Vitalant Research Institute, San Francisco, CA, USA
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute at UCL, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China
| | - Dietmar Fuchs
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Steven G Deeks
- Division of HIV, Infectious Diseases, and Global Medicine, Zuckerberg San Francisco General Hospital, University of California San Francisco, San Francisco, CA, USA
| | - Serena Spudich
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Magnus Gisslen
- Department of Infectious Diseases, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Region Västra Götaland, Sahlgrenska University Hospital, Department of Infectious Diseases, Gothenburg, Sweden
| | - Richard W Price
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Ronald Swanstrom
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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Abstract
Genetically-characterizing full-length HIV-1 RNA is critical for identifying genetically-intact genomes and for comparing these RNA genomes to proviral DNA. We have developed a method for sequencing plasma-derived RNA using long-range sequencing (PRLS assay; ∼8.3 kb from gag to the 3′ end or ∼5 kb from integrase to the 3′ end). We employed the gag-3′ PRLS assay to sequence HIV-1 RNA genomes from ART-naive participants during acute/early infection (n = 6) or chronic infection (n = 2). On average, only 65% of plasma-derived genomes were genetically-intact. Defects were found in all genomic regions but were concentrated in env and pol. We compared these genomes to near-full-length proviral sequences from paired peripheral blood mononuclear cell (PBMC) samples for the acute/early group and found that near-identical (>99.98% identical) sequences were identified only during acute infection. For three participants who initiated therapy during acute infection, we used the int-3′ PRLS assay to sequence plasma-derived genomes from an analytical treatment interruption and identified 100% identical genomes between pretherapy and rebound time points. The PRLS assay provides a new level of sensitivity for understanding the genetic composition of plasma-derived HIV-1 RNA from viremic individuals either pretherapy or after treatment interruption, which will be invaluable in assessing possible HIV-1 curative strategies. IMPORTANCE We developed novel plasma-derived RNA using long-range sequencing assays (PRLS assay; 8.3 kb, gag-3′, and 5.0 kb, int-3′). Employing the gag-3′ PRLS assay, we found that 26% to 51% of plasma-derived genomes are genetically-defective, largely as a result of frameshift mutations and deletions. These genetic defects were concentrated in the env region compared to gag and pol, likely a reflection of viral immune escape in env during untreated HIV-1 infection. Employing the int-3′ PRLS assay, we found that analytical treatment interruption (ATI) plasma-derived sequences were identical and genetically-intact. Several sequences from the ATI plasma samples were identical to viral sequences from pretherapy plasma and PBMC samples, indicating that HIV-1 reservoirs established prior to therapy contribute to viral rebound during an ATI. Therefore, near-full-length sequencing of HIV-1 particles is required to gain an accurate picture of the genetic landscape of plasma HIV-1 virions in studies of HIV-1 replication and persistence.
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Wright IA, Bale MJ, Shao W, Hu WS, Coffin JM, Van Zyl GU, Kearney MF. HIVIntact: a python-based tool for HIV-1 genome intactness inference. Retrovirology 2021; 18:16. [PMID: 34176496 PMCID: PMC8237426 DOI: 10.1186/s12977-021-00561-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/16/2021] [Indexed: 12/18/2022] Open
Abstract
The characterisation of the HIV-1 reservoir, which consists of replication-competent integrated proviruses that persist on antiretroviral therapy (ART), is made difficult by the rarity of intact proviruses relative to those that are defective. While the only conclusive test for the replication-competence of HIV-1 proviruses is carried out in cell culture, genetic characterization of genomes by near full-length (NFL) PCR and sequencing can be used to determine whether particular proviruses have insertions, deletions, or substitutions that render them defective. Proviruses that are not excluded by having such defects can be classified as genetically intact and, possibly, replication competent. Identifying and quantifying proviruses that are potentially replication-competent is important for the development of strategies towards a functional cure. However, to date, there are no programs that can be incorporated into deep-sequencing pipelines for the automated characterization and annotation of HIV genomes. Existing programs that perform this work require manual intervention, cannot be widely installed, and do not have easily adjustable settings. Here, we present HIVIntact, a python-based software tool that characterises genomic defects in NFL HIV-1 sequences, allowing putative intact genomes to be identified in-silico. Unlike other applications that assess the genetic intactness of HIV genomes, this tool can be incorporated into existing sequence-analysis pipelines and applied to large next-generation sequencing datasets. ![]()
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Affiliation(s)
- Imogen A Wright
- Division of Medical Virology, University of Stellenbosch, Tygerberg Hospital, Cape Town, South Africa.
| | - Michael J Bale
- HIV Dynamics and Replication Program, CCR, NCI-Frederick, Frederick, MD, USA.,Weill Cornell Medical College, NY, New York, USA
| | - Wei Shao
- Advanced Biomedical Computing Center, Leidos Biomedical Research, Inc, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Wei-Shau Hu
- HIV Dynamics and Replication Program, CCR, NCI-Frederick, Frederick, MD, USA
| | - John M Coffin
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, USA
| | - Gert U Van Zyl
- Division of Medical Virology, University of Stellenbosch, Tygerberg Hospital, Cape Town, South Africa
| | - Mary F Kearney
- HIV Dynamics and Replication Program, CCR, NCI-Frederick, Frederick, MD, USA
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Halvas EK, Joseph KW, Brandt LD, Guo S, Sobolewski MD, Jacobs JL, Tumiotto C, Bui JK, Cyktor JC, Keele BF, Morse GD, Bale MJ, Shao W, Kearney MF, Coffin JM, Rausch JW, Wu X, Hughes SH, Mellors JW. HIV-1 viremia not suppressible by antiretroviral therapy can originate from large T cell clones producing infectious virus. J Clin Invest 2020; 130:5847-5857. [PMID: 33016926 PMCID: PMC7598056 DOI: 10.1172/jci138099] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/22/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUNDHIV-1 viremia that is not suppressed by combination antiretroviral therapy (ART) is generally attributed to incomplete medication adherence and/or drug resistance. We evaluated individuals referred by clinicians for nonsuppressible viremia (plasma HIV-1 RNA above 40 copies/mL) despite reported adherence to ART and the absence of drug resistance to the current ART regimen.METHODSSamples were collected from at least 2 time points from 8 donors who had nonsuppressible viremia for more than 6 months. Single templates of HIV-1 RNA obtained from plasma and viral outgrowth of cultured cells and from proviral DNA were amplified by PCR and sequenced for evidence of clones of cells that produced infectious viruses. Clones were confirmed by host-proviral integration site analysis.RESULTSHIV-1 genomic RNA with identical sequences were identified in plasma samples from all 8 donors. The identical viral RNA sequences did not change over time and did not evolve resistance to the ART regimen. In 4 of the donors, viral RNA sequences obtained from plasma matched those sequences from viral outgrowth cultures, indicating that the viruses were replication competent. Integration sites for infectious proviruses from those 4 donors were mapped to the introns of the MATR3, ZNF268, ZNF721/ABCA11P, and ABCA11P genes. The sizes of the clones were estimated to be from 50 million to 350 million cells.CONCLUSIONThese findings show that clones of HIV-1-infected cells producing virus can cause failure of ART to suppress viremia. The mechanisms involved in clonal expansion and persistence need to be defined to effectively target viremia and the HIV-1 reservoir.FUNDINGNational Cancer Institute, NIH; Howard Hughes Medical Research Fellows Program, Howard Hughes Medical Institute; Bill and Melinda Gates Foundation; Office of AIDS Research; American Cancer Society; National Cancer Institute through a Leidos subcontract; National Institute for Allergy and Infectious Diseases, NIH, to the I4C Martin Delaney Collaboratory; University of Rochester Center for AIDS Research and University of Rochester HIV/AIDS Clinical Trials Unit.
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Affiliation(s)
- Elias K. Halvas
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kevin W. Joseph
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Leah D. Brandt
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shuang Guo
- Leidos Biomedical Research, Inc., Frederick, Maryland, USA
| | | | - Jana L. Jacobs
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Camille Tumiotto
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - John K. Bui
- New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Department of Medicine, New York, New York, USA
| | - Joshua C. Cyktor
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Gene D. Morse
- NYS Center of Excellence in Bioinformatics and Life Sciences, Translational Pharmacology Research Core, University at Buffalo, Buffalo, New York, USA
| | - Michael J. Bale
- HIV Dynamics and Replication Program, National Cancer Institute, Frederick, Maryland, USA
| | - Wei Shao
- Advanced Biomedical Computing Science, Frederick National Laboratory for Cancer Research (FNLCR), Frederick, Maryland, USA
| | - Mary F. Kearney
- HIV Dynamics and Replication Program, National Cancer Institute, Frederick, Maryland, USA
| | - John M. Coffin
- Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts, USA
| | - Jason W. Rausch
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Xiaolin Wu
- Leidos Biomedical Research, Inc., Frederick, Maryland, USA
| | - Stephen H. Hughes
- HIV Dynamics and Replication Program, National Cancer Institute, Frederick, Maryland, USA
| | - John W. Mellors
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Pasternak AO, Berkhout B. What do we measure when we measure cell-associated HIV RNA. Retrovirology 2018; 15:13. [PMID: 29378657 PMCID: PMC5789533 DOI: 10.1186/s12977-018-0397-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 01/16/2018] [Indexed: 12/21/2022] Open
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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