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Tóth B, Berek L, Gulácsi L, Péntek M, Zrubka Z. Automation of systematic reviews of biomedical literature: a scoping review of studies indexed in PubMed. Syst Rev 2024; 13:174. [PMID: 38978132 PMCID: PMC11229257 DOI: 10.1186/s13643-024-02592-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 06/20/2024] [Indexed: 07/10/2024] Open
Abstract
BACKGROUND The demand for high-quality systematic literature reviews (SRs) for evidence-based medical decision-making is growing. SRs are costly and require the scarce resource of highly skilled reviewers. Automation technology has been proposed to save workload and expedite the SR workflow. We aimed to provide a comprehensive overview of SR automation studies indexed in PubMed, focusing on the applicability of these technologies in real world practice. METHODS In November 2022, we extracted, combined, and ran an integrated PubMed search for SRs on SR automation. Full-text English peer-reviewed articles were included if they reported studies on SR automation methods (SSAM), or automated SRs (ASR). Bibliographic analyses and knowledge-discovery studies were excluded. Record screening was performed by single reviewers, and the selection of full text papers was performed in duplicate. We summarized the publication details, automated review stages, automation goals, applied tools, data sources, methods, results, and Google Scholar citations of SR automation studies. RESULTS From 5321 records screened by title and abstract, we included 123 full text articles, of which 108 were SSAM and 15 ASR. Automation was applied for search (19/123, 15.4%), record screening (89/123, 72.4%), full-text selection (6/123, 4.9%), data extraction (13/123, 10.6%), risk of bias assessment (9/123, 7.3%), evidence synthesis (2/123, 1.6%), assessment of evidence quality (2/123, 1.6%), and reporting (2/123, 1.6%). Multiple SR stages were automated by 11 (8.9%) studies. The performance of automated record screening varied largely across SR topics. In published ASR, we found examples of automated search, record screening, full-text selection, and data extraction. In some ASRs, automation fully complemented manual reviews to increase sensitivity rather than to save workload. Reporting of automation details was often incomplete in ASRs. CONCLUSIONS Automation techniques are being developed for all SR stages, but with limited real-world adoption. Most SR automation tools target single SR stages, with modest time savings for the entire SR process and varying sensitivity and specificity across studies. Therefore, the real-world benefits of SR automation remain uncertain. Standardizing the terminology, reporting, and metrics of study reports could enhance the adoption of SR automation techniques in real-world practice.
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Affiliation(s)
- Barbara Tóth
- Doctoral School of Innovation Management, Óbuda University, Bécsi út 96/B, Budapest, 1034, Hungary
| | - László Berek
- Doctoral School for Safety and Security, Óbuda University, Bécsi út 96/B, Budapest, 1034, Hungary
- University Library, Óbuda University, Bécsi út 96/B, Budapest, 1034, Hungary
| | - László Gulácsi
- HECON Health Economics Research Center, University Research, and Innovation Center, Óbuda University, Bécsi út 96/B, Budapest, 1034, Hungary
| | - Márta Péntek
- HECON Health Economics Research Center, University Research, and Innovation Center, Óbuda University, Bécsi út 96/B, Budapest, 1034, Hungary
| | - Zsombor Zrubka
- HECON Health Economics Research Center, University Research, and Innovation Center, Óbuda University, Bécsi út 96/B, Budapest, 1034, Hungary.
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Rashid SA, Nazakat R, Muhamad Robat R, Ismail R, Suppiah J, Rajendran K, Raj Louis Masalamany ASS, Muhamad Hendri NA, Mohamad N, Khairul Hasni NA, Suib FA, Nik Hassan NMN, Pahrol MA, Shaharudin R. Droplet digital PCR application for the detection of SARS-CoV-2 in air sample. Front Public Health 2023; 11:1208348. [PMID: 37965510 PMCID: PMC10641526 DOI: 10.3389/fpubh.2023.1208348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 10/09/2023] [Indexed: 11/16/2023] Open
Abstract
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) may transmit through airborne route particularly when the aerosol particles remain in enclosed spaces with inadequate ventilation. There has been no standard recommended method of determining the virus in air due to limitations in pre-analytical and technical aspects. Furthermore, the presence of low virus loads in air samples could result in false negatives. Our study aims to explore the feasibility of detecting SARS-CoV-2 ribonucleic acid (RNA) in air samples using droplet digital polymerase chain reaction (ddPCR). Active and passive air sampling was conducted between December 2021 and February 2022 with the presence of COVID-19 confirmed cases in two hospitals and a quarantine center in Klang Valley, Malaysia. SARS-CoV-2 RNA in air was detected and quantified using ddPCR and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The comparability of two different digital PCR platforms (QX200 and QIAcuity) to RT-PCR were also investigated. Additionally negative staining transmission electron microscopy was performed to visualize virus ultrastructure. Detection rates of SARS-CoV-2 in air samples using ddPCR were higher compared to RT-PCR, which were 15.2% (22/145) and 3.4% (5/145), respectively. The sensitivity and specificity of ddPCR was 100 and 87%, respectively. After excluding 17 negative samples (50%) by both QX200 and QIAcuity, 15% samples (5/34) were found to be positive both ddPCR and dPCR. There were 23.5% (8/34) samples that were detected positive by ddPCR but negative by dPCR. In contrast, there were 11.7% (4/34) samples that were detected positive by dPCR but negative by ddPCR. The SARS-CoV-2 detection method by ddPCR is precise and has a high sensitivity for viral RNA detection. It could provide advances in determining low viral titter in air samples to reduce false negative reports, which could complement detection by RT-PCR.
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Affiliation(s)
- Siti Aishah Rashid
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Raheel Nazakat
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Rosnawati Muhamad Robat
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Rohaida Ismail
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Jeyanthi Suppiah
- Infectious Disease Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Kamesh Rajendran
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - A. S. Santhana Raj Louis Masalamany
- Special Resource Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Nur Afrina Muhamad Hendri
- Special Resource Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Nadia Mohamad
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Nurul Amalina Khairul Hasni
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Fatin Amirah Suib
- Infectious Disease Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Nik Muhamad Nizam Nik Hassan
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Muhammad Alfatih Pahrol
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
| | - Rafiza Shaharudin
- Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Shah Alam, Selangor, Malaysia
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3
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Sustained Virologic Suppression Reduces HIV-1 DNA Proviral Levels and HIV Antibodies in Perinatally HIV-Infected Children Followed from Birth. Viruses 2022; 14:v14112350. [PMID: 36366448 PMCID: PMC9693172 DOI: 10.3390/v14112350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/16/2022] [Accepted: 10/24/2022] [Indexed: 02/01/2023] Open
Abstract
The extent to which perinatally HIV-infected children, following cART initiation, develop a low proviral reservoir burden over time, as measured by HIV DNA droplet-digital polymerase chain reaction (ddPCR) and the effect on HIV antibody is not well characterized. We measured proviral HIV DNA and plasma RNA virus load (VL) in 37 perinatally HIV-infected children at 6 months of age who initiated stable cART. At 6-11 years of age, HIV proviral DNA, HIV VL (RNA), and HIV antibody by Western Blot (WB) were assessed. CART was initiated before 6 months of age in 13 children and after 6 months in 24. At school age, the HIV DNA levels did not differ by the timing of cART, and the HIV DNA levels were lower in children with negative/indeterminate WB (p = 0.0256). Children with undetectable HIV RNA VL > 50% of the time since cART initiation had lower median DNA VL than children with undetectable VL < 50% of the time (p = 0.07). Long-term viral suppression in perinatally HIV-infected children is associated with a decrease in HIV antibodies and reduced HIV reservoirs.
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Hendricks CM, Cash MN, Tagliamonte MS, Riva A, Brander C, Llano A, Salemi M, Stevenson M, Mavian C. Discordance between HIV-1 Population in Plasma at Rebound after Structured Treatment Interruption and Archived Provirus Population in Peripheral Blood Mononuclear Cells. Microbiol Spectr 2022; 10:e0135322. [PMID: 35699458 PMCID: PMC9431602 DOI: 10.1128/spectrum.01353-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/07/2022] [Indexed: 11/20/2022] Open
Abstract
Antiretroviral therapy (ART) can sustain the suppression of plasma viremia to below detection levels. Infected individuals undergoing a treatment interruption exhibit rapid viral rebound in plasma viremia which is fueled by cellular reservoirs such as CD4+ T cells, myeloid cells, and potentially uncharacterized cellular sources. Interrogating the populations of viruses found during analytical treatment interruption (ATI) can give insights into the biologically competent reservoirs that persist under effective ART as well as the nature of the cellular reservoirs that enable viral persistence under ART. We interrogated plasma viremia from four rare cases of individuals undergoing sequential ATIs. We performed next-generation sequencing (NGS) on cell-associated viral DNA and cell-free virus to understand the interrelationship between sequential ATIs as well as the relationship between viral genomes in circulating peripheral blood mononuclear cells (PBMCs) and RNA from rebound plasma. We observed population differences between viral populations recrudescing at sequential ATIs as well as divergence between viral sequences in plasma and those in PBMCs. This indicated that viruses in PBMCs were not a major source of post-ATI viremia and highlights the role of anatomic reservoirs in post-ATI viremia and viral persistence. IMPORTANCE Even with effective ART, HIV-1 persists at undetectable levels and rebounds in individuals who stop treatment. Cellular and anatomical reservoirs ignite viral rebound upon treatment interruption, remaining one of the key obstacles for HIV-1 cure. To further examine HIV-1 persistence, a better understanding of the distinct populations that fuel viral rebound is necessary to identify and target reservoirs and the eradication of HIV-1. This study investigates the populations of viruses found from proviral genomes from PBMCs and plasma at rebound from a unique cohort of individuals who underwent multiple rounds of treatment interruption. Using NGS, we characterized the subtypes of viral sequences and found divergence in viral populations between plasma and PBMCs at each rebound, suggesting that distinct viral populations appear at each treatment interruption.
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Affiliation(s)
- Chynna M. Hendricks
- Department of Microbiology and Immunology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Melanie N. Cash
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
| | - Massimiliano S. Tagliamonte
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
| | - Alberto Riva
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, USA
| | | | - Anuska Llano
- Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Marco Salemi
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
| | - Mario Stevenson
- Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida, USA
- Division of Infectious Diseases, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Carla Mavian
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, USA
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Renault C, Bolloré K, Pisoni A, Motto-Ros C, Van de Perre P, Reynes J, Tuaillon E. Accuracy of real-time PCR and digital PCR for the monitoring of total HIV DNA under prolonged antiretroviral therapy. Sci Rep 2022; 12:9323. [PMID: 35665775 PMCID: PMC9167282 DOI: 10.1038/s41598-022-13581-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 04/21/2022] [Indexed: 12/16/2022] Open
Abstract
Total HIV DNA is a standard marker to monitor the HIV reservoir in people living with HIV. We investigated HIV DNA quantification accuracy by a real-time PCR kit (qPCR) and digital PCR (dPCR) method within the same set of primers and probes. Among 48 aviremic patients followed for up to 7 years with qPCR, the mean coefficient of variation of total HIV DNA between two successive measurements was 77% (± 0.42log10 HIVDNA copies/106 PBMC). The total HIV DNA quantified by the two PCR methods has a high correlation (0.99 and 0.83, for 8E5 and PLHIV samples, respectively), but we observed better repeatability and reproducibility of the dPCR compared to the qPCR (CV of 11.9% vs. 24.7% for qPCR, p-value = 0.024). Furthermore, we highlighted a decay of the number of HIV copies in the 8E5 cell line qPCR standard over time (from 0.73 to 0.43 copies per cell), contributing to variations of HIV DNA results in patients whose HIV reservoir should be theoretically stabilized. Our study highlighted that absolute quantification of total HIV DNA by dPCR allows more accurate monitoring of the HIV reservoir than qPCR in patients under prolonged antiretroviral therapy.
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Affiliation(s)
- Constance Renault
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Antilles University, Montpellier, France
| | - Karine Bolloré
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Antilles University, Montpellier, France
| | - Amandine Pisoni
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Antilles University, Montpellier, France.,CHU de Montpellier, Montpellier, France
| | - Camille Motto-Ros
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Antilles University, Montpellier, France
| | - Philippe Van de Perre
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Antilles University, Montpellier, France.,CHU de Montpellier, Montpellier, France
| | - Jacques Reynes
- IRD UMI 233, INSERM U1175, Montpellier University, Montpellier, France.,Infectious Diseases Department, CHU de Montpellier, Montpellier, France
| | - Edouard Tuaillon
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Antilles University, Montpellier, France. .,CHU de Montpellier, Montpellier, France.
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6
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Álvarez B, Navarrete-Muñoz MA, Briz V, Olmedillas-López S, Nistal S, Cabello A, Prieto L, Górgolas M, García-Arranz M, Benito JM, Rallón N. HIV-reservoir size is not affected either by HCV coinfection or by direct acting antivirals (DAAs) therapy. Sci Rep 2022; 12:5095. [PMID: 35332180 PMCID: PMC8948254 DOI: 10.1038/s41598-022-08871-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/28/2022] [Indexed: 12/20/2022] Open
Abstract
The role of HCV on the HIV reservoir is controversial since the reduction on HIV-DNA levels after HCV eradication with IFNα/RBV treatment seems to be the result of drugs instead of HCV clearance. We assessed whether HCV eradication can decrease HIV-DNA content in HIV/HCV-coinfected patients treated with direct-acting antivirals, DAAs (IFNα/RBV-free regimens). Cell-associated HIV-DNA was measured by ddPCR in 25 HIV-monoinfected and 25 HIV/HCV-coinfected patients. There were no differences in HIV-DNA levels between groups neither at baseline nor at 12 weeks after DAAs treatment completion. Our results indicate that HCV does not appear to influence the HIV reservoir size and suggest the lack of an anti-HIV action for DAAs.
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Affiliation(s)
- Beatriz Álvarez
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - María A Navarrete-Muñoz
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos 2, 28040, Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - Veronica Briz
- National Center of Microbiology, Institute of Health Carlos III, Majadahonda, Spain
| | - Susana Olmedillas-López
- New Therapy Group, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Sara Nistal
- Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - Alfonso Cabello
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Laura Prieto
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Miguel Górgolas
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Mariano García-Arranz
- New Therapy Group, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - José M Benito
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos 2, 28040, Madrid, Spain. .,Hospital Universitario Rey Juan Carlos, Móstoles, Spain.
| | - Norma Rallón
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos 2, 28040, Madrid, Spain. .,Hospital Universitario Rey Juan Carlos, Móstoles, Spain.
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External quality assessment of HIV-1 DNA quantification assays used in the clinical setting in Italy. Sci Rep 2022; 12:3291. [PMID: 35228581 PMCID: PMC8885833 DOI: 10.1038/s41598-022-07196-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/14/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractTotal cell-associated HIV-1 DNA is a surrogate marker of the HIV-1 reservoir, however, certified systems for its quantification are not available. The Italian HIV DNA Network was launched to validate HIV-1 DNA quantification methods in use at University and Hospital labs. A quality control panel including HIV-1 DNA standards, reconstructed blood samples (RBSs) and DNA from different HIV-1 subtypes was blindly tested by 12 participating labs by quantitative real-time PCR (n = 6), droplet digital PCR (n = 3) or both (n = 3). The median 95% hit rate was 4.6 (3.7–5.5) copies per test and linearity in the tested range was excellent (R2 = 1.000 [1.000–1.000]). The median values obtained across labs were 3,370 (2,287–4,245), 445 (299–498), 59 (40–81) and 7 (6–11) HIV-1 DNA copies, for the 3,584, 448, 56 and 7-copy standards, respectively. With RBSs, measured values were within twofold with respect to the median in two thirds of cases. HIV-1 subtypes were missed (CRF01_AE by 3 labs) or underestimated by > 1 log (subtypes A, C, D, F by one lab; CRF01_AE by one lab; CRF02_AG by one lab). The overall performance was excellent with HIV-1 DNA standards, however detection of different HIV-1 subtypes must be improved.
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Development of Droplet Digital PCR-Based Assays to Quantify HIV Proviral and Integrated DNA in Brain Tissues from Viremic Individuals with Encephalitis and Virally Suppressed Aviremic Individuals. Microbiol Spectr 2022; 10:e0085321. [PMID: 35019681 PMCID: PMC8754137 DOI: 10.1128/spectrum.00853-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Although combination antiretroviral therapy (cART) can suppress the replication of HIV, the virus persists and rebounds when treatment is stopped. To find a cure that can eradicate latent reservoir, a method should be able to quantify the lingering HIV. Unlike other digital PCR technologies, droplet digital PCR (ddPCR), provides absolute quantification of target DNA molecules using fluorescent dually labeled probes by massively partitioning the sample into droplets. ddPCR enables exquisitely sensitive detection and quantification of viral DNA from very limiting clinical samples, including brain tissues. We developed and optimized duplex ddPCR assays for the detection and quantification of HIV proviral DNA and integrated DNA in the brain of HIV-1-infected patients. We have applied these approaches to successfully analyze 77 human brain tissues obtained from 27 HIV-1-infected individuals, either fully virally suppressed or with encephalitis, and were able to quantify low levels of viral DNA. Further developments and advancement of digital PCR technology is promising to aid in accurate quantification and characterization of the persistent HIV reservoir. IMPORTANCE We developed ddPCR assays to quantitatively measure HIV DNA and used this ddPCR assays to detect and quantitatively measure HIV DNA in the archived brain tissues from HIV patients. The tissue viral loads assessed by ddPCR was highly correlative with those assessed by qPCR. HIV DNA in the brain was detected more frequently by ddPCR than by qPCR. ddPCR also showed higher sensitivity than qPCR since ddPCR detected HIV DNA signals in some tissues from virally suppressed individuals while qPCR could not.
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9
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Lei S, Chen S, Zhong Q. Digital PCR for accurate quantification of pathogens: Principles, applications, challenges and future prospects. Int J Biol Macromol 2021; 184:750-759. [PMID: 34171259 DOI: 10.1016/j.ijbiomac.2021.06.132] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 12/25/2022]
Abstract
Pathogens pose a severe threat to food safety and human health. The traditional methods for pathogen detection can't meet the growing diagnosis and control need. Digital PCR (dPCR) attracts a considerable attention for its ability to absolutely quantify pathogens with features of high selectivity, simplicity, accuracy and rapidity. The dPCR technique that achieves absolute quantification based on end-point measurement without standard curve offers a guideline for further genetic analysis and molecular diagnosis. It could contribute to the quantification of low level of nucleic acid, early detection and timely prevention of pathogenic diseases. In this review, 1442 publications about dPCR were selected and the detections of various pathogens by dPCR were reviewed comprehensively, including viruses, bacteria, parasites and fungi. A number of examples are cited to illustrate that dPCR is a new powerful tool with desired accuracy, sensitivity, and reproducibility for quantification of different types of pathogens. Moreover, the benefits, challenges and future prospects of the dPCR were also highlighted in this review.
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Affiliation(s)
- Shuwen Lei
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Song Chen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Qingping Zhong
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China.
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10
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Xu J, Kirtek T, Xu Y, Zheng H, Yao H, Ostman E, Oliver D, Malter JS, Gagan JR, SoRelle JA. Digital Droplet PCR for SARS-CoV-2 Resolves Borderline Cases. Am J Clin Pathol 2021; 155:815-822. [PMID: 33822853 PMCID: PMC8083587 DOI: 10.1093/ajcp/aqab041] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES The Bio-Rad SARS-CoV-2 ddPCR Kit (Bio-Rad Laboratories) was the first droplet digital polymerase chain reaction (ddPCR) assay to receive Food and Drug Administration (FDA) Emergency Use Authorization approval, but it has not been evaluated clinically. We describe the performance of ddPCR-in particular, its ability to confirm weak-positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) results. METHODS We clinically validated the Bio-Rad Triplex Probe ddPCR Assay. The limit of detection was determined by using serial dilutions of SARS-CoV-2 RNA in an artificial viral envelope. The ddPCR assay was performed according to the manufacturer's specifications on specimens confirmed to be positive (n = 48) or negative (n = 30) by an FDA-validated reverse transcription-polymerase chain reaction assay on the m2000 RealTime system (Abbott). Ten borderline positive cases were also evaluated. RESULTS The limit of detection was 50 copies/mL (19 of 20 positive). Forty-seven specimens spanning a range of quantification cycles (2.9-25.9 cycle numbers) were positive by this assay (47 of 48; 97.9% positive precent agreement), and 30 negative samples were confirmed as negative (30 of 30; 100% negative percent agreement). Nine of 10 borderline cases were positive when tested in triplicate. CONCLUSIONS The ddPCR of SARS-CoV-2 is an accurate method, with superior sensitivity for viral RNA detection. It could provide definitive evaluation of borderline positive cases or suspected false-negative cases.
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Affiliation(s)
- Jing Xu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Timothy Kirtek
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yan Xu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hui Zheng
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Huiyu Yao
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Dwight Oliver
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - James S Malter
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey R Gagan
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey A SoRelle
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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11
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Zhang P, Kaushik AM, Mach KE, Hsieh K, Liao JC, Wang TH. Facile syringe filter-enabled bacteria separation, enrichment, and buffer exchange for clinical isolation-free digital detection and characterization of bacterial pathogens in urine. Analyst 2021; 146:2475-2483. [PMID: 33899069 PMCID: PMC10697054 DOI: 10.1039/d1an00039j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of accelerated methods for pathogen identification (ID) and antimicrobial susceptibility testing (AST) for infectious diseases is necessary to facilitate evidence-based antibiotic therapy and reduce clinical overreliance on broad-spectrum antibiotics. Towards this end, droplet-based microfluidics has unlocked remarkably rapid diagnostic assays with single-cell and single-molecule resolution. Yet, droplet platforms invariably rely on testing purified bacterial samples that have been clinically isolated after lengthy (>16 h) plating. While plating-based clinical isolation is important for enriching and separating out bacteria from background in clinical samples and also facilitating buffer exchange, it creates a diagnostic bottleneck that ultimately precludes droplet-based methods from achieving significantly accelerated times-to-result. To alleviate this bottleneck, we have developed facile syringe filter-enabled strategies for bacterial separation, enrichment, and buffer exchange from urine samples. By selecting appropriately sized filter membranes, we separated bacterial cells from background particulates in urine samples and achieved up to 91% bacterial recovery after such 1-step filtration. When interfaced with droplet-based detection of bacterial cells, 1-step filtration improved the limit of detection for bacterial ID and quantification by over an order of magnitude. We also developed a facile buffer exchange strategy to prepare bacteria in urine samples for droplet-based AST that achieved up to 10-fold bacterial enrichment during buffer exchange. Our filtration strategies, can be easily integrated into droplet workflows, enable clinical isolation-free sample-to-answer ID and AST, and significantly accelerate the turnaround of standard infectious disease diagnostic workflows.
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Affiliation(s)
- Pengfei Zhang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
| | - Aniruddha M Kaushik
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Kathleen E Mach
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
| | - Kuangwen Hsieh
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Joseph C Liao
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
| | - Tza-Huei Wang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA. and Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
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12
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Falak S, Macdonald R, Busby EJ, O'Sullivan DM, Milavec M, Plauth A, Kammel M, Zeichhardt H, Grunert HP, Kummrow A, Huggett JF. An assessment of the reproducibility of reverse transcription digital PCR quantification of HIV-1. Methods 2021; 201:34-40. [PMID: 33722693 DOI: 10.1016/j.ymeth.2021.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/28/2021] [Accepted: 03/08/2021] [Indexed: 11/30/2022] Open
Abstract
Viral load monitoring in human immunodeficiency virus type 1 (HIV-1) infection is often performed using reverse transcription quantitative PCR (RT-qPCR) to observe response to treatment and identify the development of resistance. Traceability is achieved using a calibration hierarchy traceable to the International Unit (IU). IU values are determined using consensus agreement derived from estimations by different laboratories. Such a consensus approach is necessary due to the fact that there are currently no reference measurement procedures available that can independently assign a reference value to viral reference materials for molecular in vitro diagnostic tests. Digital PCR (dPCR) is a technique that has the potential to be used for this purpose. In this paper, we investigate the ability of reverse transcriptase dPCR (RT-dPCR) to quantify HIV-1 genomic RNA without calibration. Criteria investigated included the performance of HIV-1 RNA extraction steps, choice of reverse transcription approach and selection of target gene with assays performed in both single and duplex format. We developed a protocol which was subsequently applied by two independent laboratories as part of an external quality assurance (EQA) scheme for HIV-1 genome detection. Our findings suggest that RT-dPCR could be used as reference measurement procedure to aid the value assignment of HIV-1 reference materials to support routine calibration of HIV-1 viral load testing by RT-qPCR.
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Affiliation(s)
- Samreen Falak
- Physikalisch Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
| | - Rainer Macdonald
- Physikalisch Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - Eloise J Busby
- National Measurement Laboratory, LGC, Queens Road, Teddington, Middlesex TW11 0LY, United Kingdom
| | - Denise M O'Sullivan
- National Measurement Laboratory, LGC, Queens Road, Teddington, Middlesex TW11 0LY, United Kingdom
| | - Mojca Milavec
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Annabell Plauth
- Physikalisch Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - Martin Kammel
- INSTAND, Gesellschaft zur Foerderung der Qualitaetssicherung in medizinischen Laboratorien e.V., Ubierstr.20, D-40223 Düsseldorf, Germany; IQVD GmbH, Institut fuer Qualitaetssicherung in der Virusdiagnostik, Potsdamer Chaussee 80, 14129 Berlin, Germany
| | - Heinz Zeichhardt
- INSTAND, Gesellschaft zur Foerderung der Qualitaetssicherung in medizinischen Laboratorien e.V., Ubierstr.20, D-40223 Düsseldorf, Germany; IQVD GmbH, Institut fuer Qualitaetssicherung in der Virusdiagnostik, Potsdamer Chaussee 80, 14129 Berlin, Germany
| | - Hans-Peter Grunert
- GBD Gesellschaft fuer Biotechnologische Diagnostik mbH, Berlin, Potsdamer Chaussee 80, 14129 Berlin, Germany
| | - Andreas Kummrow
- Physikalisch Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
| | - Jim F Huggett
- National Measurement Laboratory, LGC, Queens Road, Teddington, Middlesex TW11 0LY, United Kingdom; School of Biosciences & Medicine, Faculty of Health & Medical Science, University of Surrey, Guildford GU2 7XH, United Kingdom.
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13
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Abstract
Abstract
Background
Leptospirosis, caused by pathogenic Leptospira spp., is a widespread zoonotic disease worldwide. Early diagnosis is required for proper patient management and reducing leptospirosis morbidity and mortality.
Objective
To summarize current literature regarding commonly used and new promising molecular approaches to Leptospira detection and diagnostic tests of human leptospirosis.
Method
The relevant articles in Leptospira and leptospirosis were retrieved from MEDLINE (PubMed) and Scopus.
Results
Several molecular techniques have been developed for diagnosis of human leptospirosis. Polymerase chain reaction-based techniques targeting on either lipL32 or 16S rRNA (rrs) gene are most commonly used to detect leptospiral DNA in various clinical specimens. Whole blood and urine are recommended specimens for suspected cases in the first (acute) and the second (immune) phases, respectively. Isothermal amplification with less expensive instrument is an alternative DNA detection technique that may be suitable for resource-limited laboratories.
Conclusion
Detection of leptospiral DNA in clinical specimens using molecular techniques enhances sensitivity for diagnosis of leptospirosis. The efficient and robust molecular detection especially in the early leptospiremic phase may prompt early and appropriate treatment leading to reduced morbidity and mortality of patients with leptospirosis.
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Affiliation(s)
- Teerasit Techawiwattanaboon
- Department of Microbiology, Faculty of Medicine , Chulalongkorn University , Bangkok 10330 , Thailand
- Chula Vaccine Research Center (Chula VRC), Center of Excellence in Vaccine Research and Development , Chulalongkorn University , Bangkok 10330 , Thailand
| | - Kanitha Patarakul
- Department of Microbiology, Faculty of Medicine , Chulalongkorn University , Bangkok 10330 , Thailand
- Chula Vaccine Research Center (Chula VRC), Center of Excellence in Vaccine Research and Development , Chulalongkorn University , Bangkok 10330 , Thailand
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14
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García M, López-Fernández L, Mínguez P, Morón-López S, Restrepo C, Navarrete-Muñoz MA, López-Bernaldo JC, Benguría A, García MI, Cabello A, Fernández-Guerrero M, De la Hera FJ, Estrada V, Barros C, Martínez-Picado J, Górgolas M, Benito JM, Rallón N. Transcriptional signature of resting-memory CD4 T cells differentiates spontaneous from treatment-induced HIV control. J Mol Med (Berl) 2020; 98:1093-1105. [PMID: 32556382 DOI: 10.1007/s00109-020-01930-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/04/2020] [Accepted: 05/25/2020] [Indexed: 01/29/2023]
Abstract
The HIV reservoir is the main barrier to eradicating HIV infection, and resting memory CD4 T (Trm) cells are one of the most relevant cellular component harboring latent proviruses. This is the first study analyzing the transcriptional profile of Trm cells, in two well-characterized groups of HIV patients with distinct mechanisms of viral replication control (spontaneous versus treatment-induced). We use a systems biology approach to unravel subtle but important differences in the molecular mechanisms operating at the cellular level that could be associated with the host's ability to control virus replication and persistence. Despite the absence of significant differences in the transcriptome of Trm cells between Elite Controllers (ECs) and cART-treated (TX) patients at the single gene level, we found 353 gene ontology (GO) categories upregulated in EC compared with TX. Our results suggest the existence of mechanisms at two different levels: first boosting both adaptive and innate immune responses, and second promoting active viral replication and halting HIV latency in the Trm cell compartment of ECs as compared with TX patients. These differences in the transcriptional profile of Trm cells could be involved in the lower HIV reservoir observed in ECs compared with TX individuals, although mechanistic studies are needed to confirm this hypothesis. Combining transcriptome analysis and systems biology methods is likely to provide important findings to help us in the design of therapeutic strategies aimed at purging the HIV reservoir. KEY MESSAGES: HIV-elite controllers have the lowest HIV-DNA content in resting memory CD4 T cells. HIV-ECs show a particular transcriptional profile in resting memory CD4 T cells. Molecular mechanisms of enhanced adaptative and innate immune response in HIV-ECs. High viral replication and low viral latency establishment associate to the EC status.
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Affiliation(s)
- Marcial García
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos, 2, 28040, Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - Luis López-Fernández
- Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Pablo Mínguez
- Bioinformatics Unit, Genetics Department, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD), Madrid, Spain
| | | | - Clara Restrepo
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos, 2, 28040, Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - María A Navarrete-Muñoz
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos, 2, 28040, Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | | | - Alberto Benguría
- Genomics Unit, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - María Isabel García
- Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Alfonso Cabello
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | | | | | | | | | - Javier Martínez-Picado
- irsiCaixa AIDS Research Institute, Badalona, Spain.,University of Vic-Central University of Catalonia (UVic-UCC), Vic, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Miguel Górgolas
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - José M Benito
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos, 2, 28040, Madrid, Spain. .,Hospital Universitario Rey Juan Carlos, Móstoles, Spain.
| | - Norma Rallón
- HIV and Viral Hepatitis Research Laboratory, Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Av. Reyes Católicos, 2, 28040, Madrid, Spain. .,Hospital Universitario Rey Juan Carlos, Móstoles, Spain.
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15
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Anderson EM, Simonetti FR, Gorelick RJ, Hill S, Gouzoulis MA, Bell J, Rehm C, Pérez L, Boritz E, Wu X, Wells D, Hughes SH, Rao V, Coffin JM, Kearney MF, Maldarelli F. Dynamic Shifts in the HIV Proviral Landscape During Long Term Combination Antiretroviral Therapy: Implications for Persistence and Control of HIV Infections. Viruses 2020; 12:v12020136. [PMID: 31991737 PMCID: PMC7077288 DOI: 10.3390/v12020136] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 12/19/2022] Open
Abstract
Combination antiretroviral therapy (cART) controls but does not eradicate HIV infection; HIV persistence is the principal obstacle to curing infections. The proportion of defective proviruses increases during cART, but the dynamics of this process are not well understood, and a quantitative analysis of how the proviral landscape is reshaped after cART is initiated is critical to understanding how HIV persists. Here, we studied longitudinal samples from HIV infected individuals undergoing long term cART using multiplexed Droplet Digital PCR (ddPCR) approaches to quantify the proportion of deleted proviruses in lymphocytes. In most individuals undergoing cART, HIV proviruses that contain gag are lost more quickly than those that lack gag. Increases in the fraction of gag-deleted proviruses occurred only after 1–2 years of therapy, suggesting that the immune system, and/or toxicity of viral re-activation helps to gradually shape the proviral landscape. After 10–15 years on therapy, there were as many as 3.5–5 times more proviruses in which gag was deleted or highly defective than those containing intact gag. We developed a provirus-specific ddPCR approach to quantify individual clones. Investigation of a clone of cells containing a deleted HIV provirus integrated in the HORMAD2 gene revealed that the cells underwent a massive expansion shortly after cART was initiated until the clone, which was primarily in effector memory cells, dominated the population of proviruses for over 6 years. The expansion of this HIV-infected clone had substantial effects on the overall proviral population.
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Affiliation(s)
- Elizabeth M. Anderson
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
- Department of Biology, The Catholic University of America, Washington, DC 20064, USA;
| | - Francesco R. Simonetti
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
| | - Robert J. Gorelick
- Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; (R.J.G.); (J.B.)
| | - Shawn Hill
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
| | - Monica A. Gouzoulis
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
| | - Jennifer Bell
- Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; (R.J.G.); (J.B.)
| | - Catherine Rehm
- Laboratory of Immunoregulation, NIAID, NIH, Bethesda, MD 20814, USA;
| | - Liliana Pérez
- Virus Persistence and Dynamics Section, VRC, NIAID, NIH, Bethesda, MD 20814, USA; (L.P.); (E.B.)
| | - Eli Boritz
- Virus Persistence and Dynamics Section, VRC, NIAID, NIH, Bethesda, MD 20814, USA; (L.P.); (E.B.)
| | - Xiaolin Wu
- Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; (X.W.); (D.W.)
| | - Daria Wells
- Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; (X.W.); (D.W.)
| | - Stephen H. Hughes
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
| | - Venigalla Rao
- Department of Biology, The Catholic University of America, Washington, DC 20064, USA;
| | - John M. Coffin
- Department of Biology, Tufts University, Boston, MA 02155, USA;
| | - Mary F. Kearney
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
| | - Frank Maldarelli
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD 21702, USA; (E.M.A.); (F.R.S.); (S.H.); (M.A.G.); (S.H.H.); (M.F.K.)
- Correspondence: ; Tel.: +01-301-846-5611
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16
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Frías M, Rivero-Juárez A, Téllez F, Palacios R, Jiménez-Arranz Á, Pineda JA, Merino D, Gómez-Vidal MA, Pérez-Camacho I, Camacho Á, Rivero A. Evaluation of hepatitis C viral RNA persistence in HIV-infected patients with long-term sustained virological response by droplet digital PCR. Sci Rep 2019; 9:12507. [PMID: 31467339 PMCID: PMC6715682 DOI: 10.1038/s41598-019-48966-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 08/13/2019] [Indexed: 12/12/2022] Open
Abstract
Several studies have reported the persistence of HCV RNA in liver and/or peripheral blood mononuclear cells (PBMCs) in spite of undetectable viremia in patients who have achieved sustained virological response (SVR). This event, defined as occult HCV infection, remains controversial and low titers of persistent virus may be underestimated because it has not yet been analyzed by a highly sensitive test such as droplet digital PCR (ddPCR). This method provides an alternate ultra-sensitive detection technique for very low numbers of copies of viral RNA or DNA. The aim of this study was to evaluate the persistence of HCV in HIV-coinfected patients with long-term SVR using ddPCR. For each patient, the presence of HCV RNA in serum and PBMCs at baseline was determined by nested RT-ddPCR. Patients with HCV RNA in PBMCs at baseline were followed until the end of the study. One hundred and twenty-three patients were analyzed for persistence of HCV RNA in serum and PBMCs. Persistence of HCV was not found in serum in any patient. HCV RNA was detected in PBMCs in one patient (0.81%; 95% CI: 0.04–3.94) and resolved spontaneously during follow-up. Persistence of HCV RNA in PBMCs is not a common event in HIV/HCV co-infected patients with long-term SVR evaluated by RT-ddPCR.
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Affiliation(s)
- Mario Frías
- Unidad de Enfermedades Infecciosas. Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía de Córdoba, Universidad de Córdoba, Córdoba, Spain
| | - Antonio Rivero-Juárez
- Unidad de Enfermedades Infecciosas. Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía de Córdoba, Universidad de Córdoba, Córdoba, Spain.
| | - Francisco Téllez
- Unidad Gestión Clínica Enfermedades Infecciosas, Hospital La Línea, AGS Campo de Gibraltar, Cádiz, Spain
| | - Rosario Palacios
- Unidad de Enfermedades Infecciosas. Hospital Universitario Virgen de la Victoria, Complejo Hospitalario Provincial de Málaga, Málaga, Spain
| | - Álvaro Jiménez-Arranz
- Unidad de Genómica. Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía, Universidad de Córdoba, Córdoba, Spain
| | - Juan A Pineda
- Unidad de Enfermedades Infecciosas y Microbiología, Hospital Universitario de Valme, Instituto de Biomedicina de Sevilla (iBiS), Sevilla, Spain
| | - Dolores Merino
- Unidad de Enfermedades Infecciosas, Hospitales Juan Ramón Jiménez e Infanta Elena de Huelva, Huelva, Spain
| | | | - Inés Pérez-Camacho
- Unidad de Enfermedades Infecciosas, Hospital de Poniente, El Ejido, Spain
| | - Ángela Camacho
- Unidad de Enfermedades Infecciosas. Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía de Córdoba, Universidad de Córdoba, Córdoba, Spain
| | - Antonio Rivero
- Unidad de Enfermedades Infecciosas. Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía de Córdoba, Universidad de Córdoba, Córdoba, Spain
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17
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Martinez-Hernandez F, Garcia-Heredia I, Lluesma Gomez M, Maestre-Carballa L, Martínez Martínez J, Martinez-Garcia M. Droplet Digital PCR for Estimating Absolute Abundances of Widespread Pelagibacter Viruses. Front Microbiol 2019; 10:1226. [PMID: 31244789 PMCID: PMC6581686 DOI: 10.3389/fmicb.2019.01226] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/16/2019] [Indexed: 12/14/2022] Open
Abstract
Absolute abundances of prokaryotes are typically determined by FISH. Due to the lack of a universal conserved gene among all viruses, metagenomic fragment recruitment is commonly used to estimate the relative viral abundance. However, the paucity of absolute virus abundance data hinders our ability to fully understand how viruses drive global microbial populations. The cosmopolitan marine Pelagibacter ubique is host for the highly widespread HTVC010P pelagiphage isolate and the extremely abundant uncultured virus vSAG 37-F6 recently discovered by single-virus genomics. Here we applied droplet digital PCR (ddPCR) to calculate the absolute abundance of these pelagiphage genotypes in the Mediterranean Sea and the Gulf of Maine. Abundances were between 360 and 8,510 virus mL-1 and 1,270–14,400 virus mL-1 for vSAG 37-F6 and HTVC010P, respectively. Illumina PCR-amplicon sequencing corroborated the absence of ddPCR non-specific amplifications for vSAG 37-F6, but showed an overestimation of 6% for HTVC010P from off-targets, genetically unrelated viruses. Absolute abundances of both pelagiphages, two of the most abundance marine viruses, suggest a large viral pelagiphage diversity in marine environments, and show the efficiency and power of ddPCR to disentangle the structure of marine viral communities. Results also highlight the need for a standardized workflow to obtain accurate quantification that allows cross data comparison.
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Affiliation(s)
| | | | - Monica Lluesma Gomez
- Department of Physiology, Genetics, and Microbiology, University of Alicante, Alicante, Spain
| | - Lucia Maestre-Carballa
- Department of Physiology, Genetics, and Microbiology, University of Alicante, Alicante, Spain
| | | | - Manuel Martinez-Garcia
- Department of Physiology, Genetics, and Microbiology, University of Alicante, Alicante, Spain
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18
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Tosiano MA, Jacobs JL, Shutt KA, Cyktor JC, Mellors JW. A Simpler and More Sensitive Single-Copy HIV-1 RNA Assay for Quantification of Persistent HIV-1 Viremia in Individuals on Suppressive Antiretroviral Therapy. J Clin Microbiol 2019; 57:e01714-18. [PMID: 30626659 PMCID: PMC6425167 DOI: 10.1128/jcm.01714-18] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 12/20/2018] [Indexed: 11/20/2022] Open
Abstract
A real-time quantitative reverse transcriptase PCR assay with single-copy sensitivity targeting the integrase region of HIV-1 (integrase single-copy assay [iSCA] v1.0) has been widely used to quantify plasma viremia in individuals on antiretroviral therapy (ART). iSCA v1.0 requires the use of an ultracentrifuge, and only about half of the nucleic acid extracted from plasma is assayed for HIV-1 RNA. We sought to simplify sample processing using microcentrifugation and improve assay sensitivity by testing more than 75% of the total extracted nucleic acid for HIV-1 RNA (iSCA v2.0). We evaluated the limit of detection (LoD) of iSCA v2.0 by testing replicates of low-copy plasma HIV-1 RNA standards. By probit analysis, the 95% LoD was 1 copy of HIV-1 RNA per milliliter for a 5-ml plasma sample. To compare the sensitivity of iSCA v1.0 and v2.0, we tested plasma samples with both assays from 60 participants on ART with HIV-1 RNA below 20 cps/ml. Of the 31 samples that had no detectable HIV-1 RNA by iSCA v1.0, 17 (55%) were detectable by v2.0 with an HIV-1 RNA mean value of 3.5 cps/ml. Twenty-nine samples were detectable with both assay versions, but average values of HIV-1 RNA cps/ml were 2.7-fold higher for v2.0 than v1.0. These results support the adoption of a new, more sensitive and simpler single-copy HIV-1 RNA assay (iSCA v2.0) to quantify residual viremia on ART and to assess the impact of experimental interventions designed to decrease HIV-1 reservoirs.
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Affiliation(s)
- Melissa A Tosiano
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jana L Jacobs
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kathleen A Shutt
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joshua C Cyktor
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - John W Mellors
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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19
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Myerski A, Siegel A, Engstrom J, McGowan I, Brand RM. The Use of Droplet Digital PCR to Quantify HIV-1 Replication in the Colorectal Explant Model. AIDS Res Hum Retroviruses 2019; 35:326-334. [PMID: 30618283 DOI: 10.1089/aid.2018.0227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ex vivo explant models are used to characterize in vitro efficacy of preexposure prophylaxis (PrEP) agents. Tissue is challenged with virus in culture and HIV-1 p24 levels are quantified with enzyme-linked immunosorbent assay (ELISA) on supernatants collected throughout a 14-21-day incubation. Due to the narrow dynamic range of HIV-1 p24 kits, we evaluated whether droplet digital PCR (ddPCR) provides an alternative method to quantify HIV-1 replication in supernatant samples. We used samples from the MWRI-01 study, which evaluated the pharmacokinetic/pharmacodynamic profile of long-acting rilpivirine using the explant model (McGowan et al. Lancet HIV 2016). HIV-1 pol RNA was measured with ddPCR, either directly with a one-step method or reverse transcribed to cDNA before ddPCR (two-step method) on supernatants from the MWRI-01 study. Previously analyzed HIV-1 p24 antigen levels (Alliance; Perkin-Elmer) were available for comparison purposes. Both ddPCR methods strongly correlated with HIV-1 p24 and displayed similar patterns of HIV-1 suppression before and after rilpivirine. Compared to the p24 ELISA, two-step and one-step ddPCR reduced the amount of hands-on time by approximately one-half and two-thirds, respectively. ddPCR also required less sample and based on p24 versus ddPCR correlation, could potentially reduce the explant culture time from 14 to 10 days (r2 = 0.78, p < .001) due to the increased sensitivity of ddPCR. We demonstrate that ddPCR is a suitable alternative to HIV-1 p24 ELISA to quantify HIV-1 infection in the explant model and has the potential to decrease explant culture time.
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Affiliation(s)
- Ashley Myerski
- Magee-Womens Research Institute and Foundation, Pittsburgh, Pennsylvania
| | - Aaron Siegel
- Magee-Womens Research Institute and Foundation, Pittsburgh, Pennsylvania
| | - Jarret Engstrom
- Magee-Womens Research Institute and Foundation, Pittsburgh, Pennsylvania
| | - Ian McGowan
- Magee-Womens Research Institute and Foundation, Pittsburgh, Pennsylvania
- Department of Medicine University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Rhonda M. Brand
- Magee-Womens Research Institute and Foundation, Pittsburgh, Pennsylvania
- Department of Medicine University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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20
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Application of droplet digital PCR to detect the pathogens of infectious diseases. Biosci Rep 2018; 38:BSR20181170. [PMID: 30341241 PMCID: PMC6240714 DOI: 10.1042/bsr20181170] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/07/2018] [Accepted: 10/09/2018] [Indexed: 12/20/2022] Open
Abstract
Polymerase chain reaction (PCR) is a molecular biology technique used to multiply certain deoxyribonucleic acid (DNA) fragments. It is a common and indispensable technique that has been applied in many areas, especially in clinical laboratories. The third generation of polymerase chain reaction, droplet digital polymerase chain reaction (ddPCR), is a biotechnological refinement of conventional polymerase chain reaction methods that can be used to directly quantify and clonally amplify DNA. Droplet digital polymerase chain reaction is now widely used in low-abundance nucleic acid detection and is useful in diagnosis of infectious diseases. Here, we summarized the potential advantages of droplet digital polymerase chain reaction in clinical diagnosis of infectious diseases, including viral diseases, bacterial diseases and parasite infections, concluded that ddPCR provides a more sensitive, accurate, and reproducible detection of low-abundance pathogens and may be a better choice than quantitative polymerase chain reaction for clinical applications in the future.
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21
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Kaushik AM, Hsieh K, Wang TH. Droplet microfluidics for high-sensitivity and high-throughput detection and screening of disease biomarkers. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2018; 10:e1522. [PMID: 29797414 PMCID: PMC6185786 DOI: 10.1002/wnan.1522] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 03/02/2018] [Accepted: 03/10/2018] [Indexed: 12/17/2022]
Abstract
Biomarkers are nucleic acids, proteins, single cells, or small molecules in human tissues or biological fluids whose reliable detection can be used to confirm or predict disease and disease states. Sensitive detection of biomarkers is therefore critical in a variety of applications including disease diagnostics, therapeutics, and drug screening. Unfortunately for many diseases, low abundance of biomarkers in human samples and low sample volumes render standard benchtop platforms like 96-well plates ineffective for reliable detection and screening. Discretization of bulk samples into a large number of small volumes (fL-nL) via droplet microfluidic technology offers a promising solution for high-sensitivity and high-throughput detection and screening of biomarkers. Several microfluidic strategies exist for high-throughput biomarker digitization into droplets, and these strategies have been utilized by numerous droplet platforms for nucleic acid, protein, and single-cell detection and screening. While the potential of droplet-based platforms has led to burgeoning interest in droplets, seamless integration of sample preparation technologies and automation of platforms from biological sample to answer remain critical components that can render these platforms useful in the clinical setting in the near future. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > Diagnostic Nanodevices Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.
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Affiliation(s)
| | - Kuangwen Hsieh
- Department of Mechanical Engineering, Johns Hopkins University
| | - Tza-Huei Wang
- Department of Mechanical Engineering, Department of Biomedical Engineering, Johns Hopkins University
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22
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García M, Navarrete-Muñoz MA, Ligos JM, Cabello A, Restrepo C, López-Bernaldo JC, de la Hera FJ, Barros C, Montoya M, Fernández-Guerrero M, Estrada V, Górgolas M, Benito JM, Rallón N. CD32 Expression is not Associated to HIV-DNA content in CD4 cell subsets of individuals with Different Levels of HIV Control. Sci Rep 2018; 8:15541. [PMID: 30341387 PMCID: PMC6195600 DOI: 10.1038/s41598-018-33749-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 10/05/2018] [Indexed: 01/20/2023] Open
Abstract
A recent study has pointed out to CD32a as a potential biomarker of HIV-persistent CD4 cells. We have characterized the level and phenotype of CD32+ cells contained in different subsets of CD4 T-cells and its potential correlation with level of total HIV-DNA in thirty HIV patients (10 typical progressors naïve for cART, 10 cART-suppressed patients, and 10 elite controllers). Total HIV-DNA was quantified in different subsets of CD4 T-cells: Trm and pTfh cells. Level and immunephenotype of CD32+ cells were analyzed in these same subsets by flow cytometry. CD32 expression in Trm and pTfh subsets was similar in the different groups, and there was no significant correlation between the level of total HIV-DNA and the level of CD32 expression in these subsets. However, total HIV-DNA level was correlated with expression of CD127 (rho = -0.46, p = 0.043) and of CCR6 (rho = -0.418, p = 0.027) on CD32+ cells. Our results do not support CD32 as a biomarker of total HIV-DNA content. However, analyzing the expression of certain markers by CD32+ cells could improve the utility of this marker in the clinical setting, prompting the necessity of further studies to both validate our results and to explore the potential utility of certain markers expressed by CD32+ cells.
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Affiliation(s)
- Marcial García
- Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - María Angeles Navarrete-Muñoz
- Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | - José M Ligos
- Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Alfonso Cabello
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Clara Restrepo
- Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Hospital Universitario Rey Juan Carlos, Móstoles, Spain
| | | | | | | | - María Montoya
- Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | | | | | - Miguel Górgolas
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - José M Benito
- Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain. .,Hospital Universitario Rey Juan Carlos, Móstoles, Spain.
| | - Norma Rallón
- Instituto de Investigación Sanitaria Fundación Jiménez Díaz, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain. .,Hospital Universitario Rey Juan Carlos, Móstoles, Spain.
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23
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Anderson EM, Maldarelli F. Quantification of HIV DNA Using Droplet Digital PCR Techniques. ACTA ACUST UNITED AC 2018; 51:e62. [PMID: 30253074 DOI: 10.1002/cpmc.62] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
HIV persists, despite effective antiretroviral therapy, in long-lived cells, posing a major barrier toward a cure. A key step in the HIV replication cycle and a hallmark of the Retroviridae family is the integration of the viral DNA into the host genome. Once integrated, HIV expression is regulated by host machinery and the provirus persists until the cell dies. A reservoir of cells harboring replication-competent proviruses can survive for years, and mechanisms that maintain that reservoir are under investigation. The majority of integrated proviruses, however, are defective or have large deletions, and the composition of the proviral landscape during therapy remains unknown. Methods to quantify HIV proviruses are useful in investigating HIV persistence. Presented in this unit is a method for total HIV DNA quantification of various HIV genome targets that utilizes the next-generation PCR platform, digital PCR. The abundance of various HIV gene targets reflects the overall proviral composition. In this protocol, total genomic DNA is isolated from patient-derived cells and then used as a template for droplet digital PCR, in which the PCR reaction is partitioned into approximately 20,000 individual droplets, PCR amplified to an end point, and subjected to absolute quantification by counting the number of positive and negative droplets. Copy number is directly calculated using straightforward Poisson correction. Additionally, this methodological approach can be used to obtain absolute quantification of other DNA targets. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
| | - Frank Maldarelli
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, Maryland
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24
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Bosman KJ, Wensing AMJ, Pijning AE, van Snippenberg WJ, van Ham PM, de Jong DMC, Hoepelman AIM, Nijhuis M. Development of sensitive ddPCR assays to reliably quantify the proviral DNA reservoir in all common circulating HIV subtypes and recombinant forms. J Int AIDS Soc 2018; 21:e25185. [PMID: 30375818 PMCID: PMC6138437 DOI: 10.1002/jia2.25185] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/17/2018] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION The latent reservoir is the main barrier on the road to HIV cure, and clinical approaches towards eradication are often evaluated by their effect on proviral DNA. To ensure inclusiveness and representativeness in HIV cure studies, proviral DNA quantification assays that are able to detect all common circulating HIV clades are urgently needed. Here, three HIV DNA assays targeting three different genomic regions were evaluated for their sensitivity and subtype-tolerance using digital PCR. METHODS A subtype-B-specific assay targeting gag (GAG) and two assays targeting conserved sequences in ltr and pol (LTR and JO) were assessed for their sensitivity and subtype-tolerance in digital PCR (Bio-Rad QX200), using a panel of serially diluted subtype reference plasmids as well as a panel of clinical isolates. Both panels represent subtypes A, B, C, D, F, G and circulating recombinant forms (CRFs) AE and AG, which together are responsible for 94% of HIV infections worldwide. RESULTS HIV subtype was observed to greatly affect HIV DNA quantification results. Robust regression analysis of the serially diluted plasmid panel showed that the GAG assay was only able to linearly quantify subtype B, D and G isolates (4/13 reference plasmids, average R2 = 0.99), whereas LTR and JO were able to quantify all tested isolates (13/13 reference plasmids, respective average R2 = 0.99 and 0.98). In the clinical isolates panel, isolates were considered detectable if all replicates produced a positive result. The GAG assay could detect HIV DNA in four out of five subtype B and one out of two subtype D isolates, whereas the LTR and JO assays detected HIV DNA in all twenty-nine tested isolates. LTR and JO results were found to be equally precise but more precise than GAG. CONCLUSIONS The results demonstrate the need for a careful validation of proviral reservoir quantification assays prior to investigations into non-B subtype reservoirs. The LTR and JO assays can sensitively and reliably quantify HIV DNA in a panel that represents the worldwide most prevalent subtypes and CRFs (A, B, C, D, AE, F, G and AG), justifying their application in future trials aimed at global HIV cure.
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Affiliation(s)
- Kobus J Bosman
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Annemarie MJ Wensing
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Aster E Pijning
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
| | | | - Petra M van Ham
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Dorien MC de Jong
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Andy IM Hoepelman
- Department of Internal Medicine and Infectious DiseasesUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Monique Nijhuis
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
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25
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Kint S, De Spiegelaere W, De Kesel J, Vandekerckhove L, Van Criekinge W. Evaluation of bisulfite kits for DNA methylation profiling in terms of DNA fragmentation and DNA recovery using digital PCR. PLoS One 2018; 13:e0199091. [PMID: 29902267 PMCID: PMC6002050 DOI: 10.1371/journal.pone.0199091] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/31/2018] [Indexed: 02/06/2023] Open
Abstract
DNA methylation is one of the most important epigenetic modifications in the regulation of gene transcription. The current gold standard to study this modification is bisulfite sequencing. Although multiple commercial bisulfite treatment kits provide good conversion efficiencies, DNA loss and especially DNA fragmentation remain troublesome. This hampers DNA methylation profiling of long DNA sequences. Here, we explored the performance of twelve commercial bisulfite kits by an in-depth comparison of DNA fragmentation using gel electrophoresis, qPCR and digital PCR, DNA recovery by spectroscopic measurements and digital PCR and conversion efficiency by next generation sequencing. The results show a clear performance difference between the bisulfite kits, and depending on the specific goal of the study, the most appropriate kit might differ. Moreover, we demonstrated that digital PCR is a valuable method to monitor both DNA fragmentation as well as DNA recovery after bisulfite treatment.
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Affiliation(s)
- Sam Kint
- Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- HIV Cure Research Center, Department of Internal Medicine, Faculty of Medicine and Health Sciences, Ghent University and Ghent University Hospital, Ghent, Belgium
- * E-mail:
| | - Ward De Spiegelaere
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Jonas De Kesel
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Linos Vandekerckhove
- HIV Cure Research Center, Department of Internal Medicine, Faculty of Medicine and Health Sciences, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Wim Van Criekinge
- Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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26
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Rouzioux C, Avettand-Fenoël V. Total HIV DNA: a global marker of HIV persistence. Retrovirology 2018; 15:30. [PMID: 29615133 PMCID: PMC5883363 DOI: 10.1186/s12977-018-0412-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/26/2018] [Indexed: 11/10/2022] Open
Abstract
Among the different markers of HIV persistence in infected cells, total HIV DNA is to date the most widely used. It allows an overall quantification of all viral forms of HIV DNA in infected cells, each playing a different role in HIV replication and pathophysiology. The real-time PCR technology is to date, a precise, sensitive and reproducible technology that allows the description of the distribution of HIV infected cells in blood and tissues. The objective of this review is to present some examples which show the interest to quantify total HIV DNA levels. This marker brought an undeniable and considerable contribution to reservoir studies. Many results, both in clinical and basic research, allowed to get a large overview of the distribution of infected cells in the body, at all stages of HIV disease and during therapy. Future clinical studies aiming at reducing HIV reservoirs will benefit from HIV DNA quantification in blood and tissues, in association with other markers of HIV reservoir activity.
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Affiliation(s)
- Christine Rouzioux
- Laboratoire de Virologie, APHP Hôpital Necker Enfants Malades, Paris, France. .,EA 7327, Université Paris Descartes, Sorbonne Paris-Cité, Paris, France.
| | - Véronique Avettand-Fenoël
- Laboratoire de Virologie, APHP Hôpital Necker Enfants Malades, Paris, France.,EA 7327, Université Paris Descartes, Sorbonne Paris-Cité, Paris, France
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27
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Powell EA, Babady NE. Digital PCR in the Clinical Microbiology Laboratory: Another Tool on the Molecular Horizon. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.clinmicnews.2018.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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28
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Exploring viral reservoir: The combining approach of cell sorting and droplet digital PCR. Methods 2017; 134-135:98-105. [PMID: 29197654 DOI: 10.1016/j.ymeth.2017.11.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/24/2017] [Accepted: 11/27/2017] [Indexed: 12/12/2022] Open
Abstract
Combined antiretroviral therapy (cART) blocks different steps of HIV replication and maintains plasma viral RNA at undetectable levels. The virus can remain in long-living cells and create a reservoir where HIV can restart replicating after cART discontinuation. A persistent viral production triggers and maintains a persistent immune activation, which is a well-known feature of chronic HIV infection, and contributes either to precocious aging, or to the increased incidence of morbidity and mortality of HIV positive patients. The new frontier of the treatment of HIV infection is nowadays eradication of the virus from all host cells and tissues. For this reason, it is crucial to have a clear and precise idea of where the virus hides, and which are the cells that keep it silent. Important efforts have been made to improve the detection of viral reservoirs, and new techniques are now giving the opportunity to characterize viral reservoirs. Among these techniques, a strategic approach based upon cell sorting and droplet digital PCR (ddPCR) is opening new horizons and opportunities of research. This review provides an overview of the methods that combine cell sorting and ddPCR for the quantification of HIV DNA in different cell types, and for the detection of its maintenance.
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29
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Peripheral T follicular helper Cells Make a Difference in HIV Reservoir Size between Elite Controllers and Patients on Successful cART. Sci Rep 2017; 7:16799. [PMID: 29196729 PMCID: PMC5711909 DOI: 10.1038/s41598-017-17057-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 11/21/2017] [Indexed: 01/24/2023] Open
Abstract
HIV latency is the main barrier to HIV eradication. Peripheral T follicular helper (pTfh) cells have a prominent role in HIV persistence. Herein, we analyzed the HIV reservoir size within memory CD4+ T-cell subsets in patients with HIV replication control. Twenty HIV-infected patients with suppressed HIV replication were included, with 10 elite controllers (EC) and 10 treated (TX) individuals. The HIV reservoir size was analyzed in resting memory CD4+ T-cells (Trm), pTfh, and non-pTfh cells using an ultrasensitive digital-droplet-PCR assay. Inter-group and intra-group differences were tested using non-parametric tests. Compared with the TX patients, the EC patients had smaller HIV reservoir not only in Trm but also in pTfh and non-pTfh subsets of memory CD4+ T-cells. The largest differences were observed in pTfh cells (p = 0.025). The pTfh and non-pTfh cells harbored similar levels of HIV-DNA in the EC (p = 0.60) and TX patients (p = 0.17); however, the contribution to HIV-DNA levels in memory CD4+ T-cells varied among the pTfh and non-pTfh subsets in both groups of patients. The EC patients showed smaller HIV reservoir in memory CD4+ cells, especially in the pTfh subset, a population of cells with a pivotal role in the antiviral immune response, suggesting a potential link between low levels of infection in pTfh cells and the ability of the EC patients to spontaneously control HIV replication.
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30
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Ruhanya V, Jacobs GB, Glashoff RH, Engelbrecht S. Clinical Relevance of Total HIV DNA in Peripheral Blood Mononuclear Cell Compartments as a Biomarker of HIV-Associated Neurocognitive Disorders (HAND). Viruses 2017; 9:E324. [PMID: 29088095 PMCID: PMC5707531 DOI: 10.3390/v9110324] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 12/19/2022] Open
Abstract
The pathogenesis of HIV-associated neurocognitive disorders is complex and multifactorial. It is hypothesized that the critical events initiating this condition occur outside the brain, particularly in the peripheral blood. Diagnoses of HIV-induced neurocognitive disorders largely rely on neuropsychometric assessments, which are not precise. Total HIV DNA in the peripheral blood mononuclear cells (PBMCs), quantified by PCR, correlate with disease progression, which is a promising biomarker to predict HAND. Numerous PCR assays for HIV DNA in cell compartments are prone to variation due to the lack of standardization and, therefore, their utility in predicting HAND produced different outcomes. This review evaluates the clinical relevance of total HIV DNA in circulating mononuclear cells using different published quantitative PCR (qPCR) protocols. The rationale is to shed light on the most appropriate assays and sample types used to accurately quantify HIV DNA load, which predicts severity of neurocognitive impairment. The role of monocytes as a vehicle for trafficking HIV into the CNS makes it the most suitable sample for determining a HAND associated reservoir. Studies have also shown significant associations between monocyte HIV DNA levels with markers of neurodamage. However, qPCR assays using PBMCs are cheaper and available commercially, thus could be beneficial in clinical settings. There is need, however, to standardise DNA extraction, normalisation and limit of detection.
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Affiliation(s)
- Vurayai Ruhanya
- Division of Medical Virology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Avenue, P.O. Box 241, Cape Town 8000, South Africa.
- Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, P.O. Box A178, Avondale Harare 00263, Zimbabwe.
| | - Graeme B Jacobs
- Division of Medical Virology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Avenue, P.O. Box 241, Cape Town 8000, South Africa.
| | - Richard H Glashoff
- Division of Medical Microbiology and Immunology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Avenue, P.O. Box 241, Cape Town 8000, South Africa.
- Division of Medical Microbiology and Immunology, National Health Laboratory Service (NHLS), Tygerberg Business Unit, P.O. Box 241, Cape Town 8000, South Africa.
| | - Susan Engelbrecht
- Division of Medical Virology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Avenue, P.O. Box 241, Cape Town 8000, South Africa.
- Division of Medical Virology, National Health Laboratory Service (NHLS), Tygerberg Business Unit, P.O. Box 241, Cape Town 8000, South Africa.
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31
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Busby E, Whale AS, Ferns RB, Grant PR, Morley G, Campbell J, Foy CA, Nastouli E, Huggett JF, Garson JA. Instability of 8E5 calibration standard revealed by digital PCR risks inaccurate quantification of HIV DNA in clinical samples by qPCR. Sci Rep 2017; 7:1209. [PMID: 28446770 PMCID: PMC5430807 DOI: 10.1038/s41598-017-01221-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/22/2017] [Indexed: 11/09/2022] Open
Abstract
ABTRACT Establishing a cure for HIV is hindered by the persistence of latently infected cells which constitute the viral reservoir. Real-time qPCR, used for quantification of this reservoir by measuring HIV DNA, requires external calibration; a common choice of calibrator is the 8E5 cell line, which is assumed to be stable and to contain one HIV provirus per cell. In contrast, digital PCR requires no external calibration and potentially provides 'absolute' quantification. We compared the performance of qPCR and dPCR in quantifying HIV DNA in 18 patient samples. HIV DNA was detected in 18 by qPCR and in 15 by dPCR, the difference being due to the smaller sample volume analysed by dPCR. There was good quantitative correlation (R2 = 0.86) between the techniques but on average dPCR values were only 60% of qPCR values. Surprisingly, investigation revealed that this discrepancy was due to loss of HIV DNA from the 8E5 cell calibrant. 8E5 extracts from two other sources were also shown to have significantly less than one HIV DNA copy per cell and progressive loss of HIV from 8E5 cells during culture was demonstrated. We therefore suggest that the copy number of HIV in 8E5 extracts be established by dPCR prior to use as calibrator.
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Affiliation(s)
- Eloise Busby
- Molecular and Cell Biology Team, LGC, Teddington, UK
| | | | - R Bridget Ferns
- Department of Infection, Division of Infection and Immunity, University College London, London, UK
| | - Paul R Grant
- Department of Clinical Virology, University College London Hospital NHS Foundation Trust, and the UCL/UCLH NIHR Biomedical Research Centre, London, UK
| | - Gary Morley
- Molecular and Cell Biology Team, LGC, Teddington, UK
| | | | - Carole A Foy
- Molecular and Cell Biology Team, LGC, Teddington, UK
| | - Eleni Nastouli
- Department of Clinical Virology, University College London Hospital NHS Foundation Trust, and the UCL/UCLH NIHR Biomedical Research Centre, London, UK.,Department of Population Policy and Practice, UCL GOS Institute of Child Health, London, UK
| | - Jim F Huggett
- Molecular and Cell Biology Team, LGC, Teddington, UK. .,School of Biosciences & Medicine, Faculty of Health & Medical Science, University of Surrey, Guildford, GU2 7XH, UK.
| | - Jeremy A Garson
- Department of Infection, Division of Infection and Immunity, University College London, London, UK. .,National Transfusion Microbiology Laboratories, NHS Blood and Transplant, Colindale, London, UK.
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32
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Ding Y, Choo J, deMello AJ. From single-molecule detection to next-generation sequencing: microfluidic droplets for high-throughput nucleic acid analysis. MICROFLUIDICS AND NANOFLUIDICS 2017; 21:58. [PMID: 32214953 PMCID: PMC7087872 DOI: 10.1007/s10404-017-1889-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 02/22/2017] [Indexed: 05/27/2023]
Abstract
Droplet-based microfluidic technologies have proved themselves to be of significant utility in the performance of high-throughput chemical and biological experiments. By encapsulating and isolating reagents within femtoliter-nanoliter droplet, millions of (bio) chemical reactions can be processed in a parallel fashion and on ultra-short timescales. Recent applications of such technologies to genetic analysis have suggested significant utility in low-cost, efficient and rapid workflows for DNA amplification, rare mutation detection, antibody screening and next-generation sequencing. To this end, we describe and highlight some of the most interesting recent developments and applications of droplet-based microfluidics in the broad area of nucleic acid analysis. In addition, we also present a cursory description of some of the most essential functional components, which allow the creation of integrated and complex workflows based on flowing streams of droplets.
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Affiliation(s)
- Yun Ding
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zurich, Switzerland
| | - Jaebum Choo
- Department of Bionano Technology, Hanyang University, Ansan, 15588 Republic of Korea
| | - Andrew J. deMello
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zurich, Switzerland
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