1
|
Sharma KK, Przybilla F, Restle T, Godet J, Mély Y. FRET-based assay to screen inhibitors of HIV-1 reverse transcriptase and nucleocapsid protein. Nucleic Acids Res 2016; 44:e74. [PMID: 26762982 PMCID: PMC4856972 DOI: 10.1093/nar/gkv1532] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 12/23/2015] [Indexed: 12/15/2022] Open
Abstract
During HIV-1 reverse transcription, the single-stranded RNA genome is converted into proviral double stranded DNA by Reverse Transcriptase (RT) within a reverse transcription complex composed of the genomic RNA and a number of HIV-1 encoded proteins, including the nucleocapsid protein NCp7. Here, we developed a one-step and one-pot RT polymerization assay. In this in vitro assay, RT polymerization is monitored in real-time by Förster resonance energy transfer (FRET) using a commercially available doubly-labeled primer/template DNA. The assay can monitor and quantify RT polymerization activity as well as its promotion by NCp7. Z-factor values as high as 0.89 were obtained, indicating that the assay is suitable for high-throughput drug screening. Using Nevirapine and AZT as prototypical RT inhibitors, reliable IC50 values were obtained from the changes in the RT polymerization kinetics. Interestingly, the assay can also detect NCp7 inhibitors, making it suitable for high-throughput screening of drugs targeting RT, NCp7 or simultaneously, both proteins.
Collapse
Affiliation(s)
- Kamal K Sharma
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Frédéric Przybilla
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Tobias Restle
- Institute für Molekulare Medizin, Universitätsklinikum Schleswig-Holstein, Universität zu Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Julien Godet
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France Département d'Information Médicale et de Biostatistiques, Hôpitaux Universitaires de Strasbourg, 1, pl de l'Hôpital, 67400 Strasbourg, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| |
Collapse
|
2
|
Sharma KK, Przybilla F, Restle T, Boudier C, Godet J, Mély Y. Reverse Transcriptase in Action: FRET-Based Assay for Monitoring Flipping and Polymerase Activity in Real Time. Anal Chem 2015; 87:7690-7. [PMID: 26125954 DOI: 10.1021/acs.analchem.5b01126] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Reverse transcriptase (RT) of human immunodeficiency virus-1 (HIV-1) is a multifunctional enzyme that catalyzes the conversion of the single stranded viral RNA genome into double-stranded DNA, competent for host-cell integration. RT is endowed with RNA- and DNA-dependent DNA polymerase activity and DNA-directed RNA hydrolysis (RNase H activity). As a key enzyme of reverse transcription, RT is a key target of currently used highly active antiretroviral therapy (HAART), though RT inhibitors offer generally a poor resistance profile, urging new RT inhibitors to be developed. Using single molecule fluorescence approaches, it has been recently shown that RT binding orientation and dynamics on its substrate play a critical role in its activity. Currently, most in vitro RT activity assays, inherently end-point measurements, are based on the detection of reaction products by using radio-labeled or chemically modified nucleotides. Here, we propose a simple and continuous real-time Förster resonance energy transfer (FRET) based-assay for the direct measurement of RT's binding orientation and polymerase activity, with the use of conventional steady-state fluorescence spectroscopy. Under our working conditions, the change in binding orientation and the primer elongation step can be visualized separately on the basis of their opposite fluorescence changes and their different kinetics. The assay presented can easily discriminate non-nucleoside RT inhibitors from nucleoside RT inhibitors and determine reliably their potency. This one-step and one-pot assay constitutes an improved alternative to the currently used screening assays to disclose new anti-RT drugs and identify at the same time the class to which they belong.
Collapse
Affiliation(s)
- K K Sharma
- †Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - F Przybilla
- †Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - T Restle
- ‡Institute für Molekulare Medizin, Universitätsklinikum Schleswig-Holstein, Universität zu Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Schleswig-Holstein, Germany
| | - C Boudier
- †Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - J Godet
- †Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France.,§Département d'Information Médicale et de Biostatistiques, Hôpitaux Universitaires de Strasbourg, 1, pl de l'Hôpital, 67400 Strasbourg, France
| | - Y Mély
- †Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401 Illkirch, France
| |
Collapse
|
3
|
Ammersbach M, Bienzle D. Methods for assessing feline immunodeficiency virus infection, infectivity and purification. Vet Immunol Immunopathol 2011; 143:202-14. [DOI: 10.1016/j.vetimm.2011.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
4
|
Zhang C, Wu Y, Sun Y, Hong C, Xiang K, Guo Y, Bartlam M, Lou Z. A novel non-radioactive assay for HIV-RT (RdDp) based on pyrosequencing for high-throughput drug screening. Protein Cell 2010; 1:284-90. [PMID: 21203975 DOI: 10.1007/s13238-010-0031-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 01/15/2010] [Indexed: 11/28/2022] Open
Abstract
Current in vitro assays for the activity of HIV-RT (reverse transcriptase) require radio-labeled or chemically modified nucleotides to detect reaction products. However, these assays are inherently end-point measurements and labor intensive. Here we describe a novel non-radioactive assay based on the principle of pyrosequencing coupled-enzyme system to monitor the activity of HIV-RT by indirectly measuring the release of pyrophosphate (PP(i)), which is generated during nascent strand synthesis. The results show that our assay could monitor HIV-RT activity with high sensitivity and is suitable for rapid high-throughput drug screening targeting anti-HIV therapies due to its high speed and convenience. Moreover, this assay can be used to measure primase activity in an easy and sensitive manner, which suggests that this novel approach could be wildly used to analyze the activity of PP(i)-generated and ATP-free enzyme reactions.
Collapse
Affiliation(s)
- Chang Zhang
- Tsinghua-Nankai-IBP Joint Research Group for Structural Biology, Tsinghua University, Beijing 100084, China
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Zhang Z, Zheng M, Du L, Shen J, Luo X, Zhu W, Jiang H. Towards discovering dual functional inhibitors against both wild type and K103N mutant HIV-1 reverse transcriptases: molecular docking and QSAR studies on 4,1-benzoxazepinone analogues. J Comput Aided Mol Des 2006; 20:281-93. [PMID: 16897578 DOI: 10.1007/s10822-006-9050-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2006] [Accepted: 05/26/2006] [Indexed: 10/24/2022]
Abstract
To find useful information for discovering dual functional inhibitors against both wild type (WT) and K103N mutant reverse transcriptases (RTs) of HIV-1, molecular docking and 3D-QSAR approaches were applied to a set of twenty-five 4,1-benzoxazepinone analogues of efavirenz (SUSTIVA), some of them are active against the two RTs. 3D-QSAR models were constructed, based on their binding conformations determined by molecular docking, with r(2)(cv) values ranging from 0.656 to 0.834 for CoMFA and CoMSIA, respectively. The models were then validated to be highly predictive and extrapolative by inhibitors in two test sets with different molecular skeletons. Furthermore, CoMFA models were found to be well matched with the binding sites of both WT and K103N RTs. Finally, a reasonable pharmacophore model of 4,1-benzoxazepinones were established. The application of the model not only successfully differentiated the experimentally determined inhibitors from non-inhibitors, but also discovered two potent inhibitors from the compound database SPECS. On the basis of both the 3D-QSAR and pharmacophore models, new clues for discovering and designing potent dual functional drug leads against HIV-1 were proposed: (i) adopting positively charged aliphatic group at the cis-substituent of C3; (ii) reducing the electronic density at the position of O4; (iii) positioning a small branched aliphatic group at position of C5; (iv) using the negatively charged bulky substituents at position of C7.
Collapse
Affiliation(s)
- Zhenshan Zhang
- Center for Drug Discovery and Design, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China
| | | | | | | | | | | | | |
Collapse
|
6
|
Kothapalli R, Danyluck GM, Bailey RD, Loughran TP. Problems associated with product enhancement reverse transcriptase assay using bacteriophage MS2 RNA as a template. J Virol Methods 2003; 109:203-7. [PMID: 12711064 DOI: 10.1016/s0166-0934(03)00072-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In order to identify the reverse transcriptase activity in sera and conditioned media from peripheral blood mononuclear cells (PBMCs) of large granular lymphocyte leukemia patients product enhanced reverse transcriptase activity (PERT) assays were performed using bacteriophage MS2 RNA as a template. All samples obtained from conditioned media of virus-infected cell lines as well as PBMCs of lymphocytic leukemia patients and normal healthy individuals tested positive with this assay. Therefore the validity of the assay was questioned. Careful evaluation of the assay revealed that some of the essential reagents used, such as Taq DNA polymerase and RNase inhibitor contained indigenous amplifiable DNA. DNase I treatment of Taq DNA polymerase before PCR reduced the product significantly. Moreover, no false positive results were observed when encephalomyocarditis virus RNA was used instead of MS2 RNA as the template. These results suggest a need for caution when using bacteriophage MS2 RNA as the template in PERT assays to confirm the presence of retroviral infection or for identification of novel retroviruses.
Collapse
Affiliation(s)
- Ravi Kothapalli
- Hematologic Malignancies, Molecular Oncology Program, H. Lee Moffitt Cancer Center and Research Institute, Department of Internal Medicine, University of South Florida, College of Medicine, Tampa, FL 33612, USA.
| | | | | | | |
Collapse
|
7
|
Odawara F, Abe H, Kohno T, Nagai-Fujii Y, Arai K, Imamura S, Misaki H, Azuma H, Ikebuchi K, Ikeda H, Mohan S, Sano K. A highly sensitive chemiluminescent reverse transcriptase assay for human immunodeficiency virus. J Virol Methods 2002; 106:115-24. [PMID: 12367736 DOI: 10.1016/s0166-0934(02)00142-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A simple and highly sensitive reverse transcriptase (RT) assay was developed by combining a previously reported non-radioisotopic RT assay with the use of a template-primer-immobilized microplate, an enzyme capture protocol, product digestion and a chemiluminescent substrate. The assay was able to detect directly the RT activity in serum samples, plasma and cell culture medium without the need for concentration and extraction of the enzyme. The assay was able to detect RT activity equivalent to 100 virions/ml of HIV-1. These results suggest that this highly sensitive chemiluminescent RT assay can be used not only for virological investigation but also for routine screening of biopharmaceuticals.
Collapse
Affiliation(s)
- Fumitomo Odawara
- Fine Chemicals and Diagnostic Division, Asahi Kasei Corporation, 632-1 Mifuku, Ohito-cho, Tagata-gun, Shizuoka 410-2321, Japan.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Zhang JH, Chen T, Nguyen SH, Oldenburg KR. A high-throughput homogeneous assay for reverse transcriptase using generic reagents and time-resolved fluorescence detection. Anal Biochem 2000; 281:182-6. [PMID: 10870833 DOI: 10.1006/abio.2000.4567] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A homogeneous time-resolved fluorescence (HTRF) assay has been developed for determining the activity of HIV reverse transcriptase (HIV-RT). By using a sequential capping strategy, the assay has been configured to utilize only generic reagents such as biotinylated dUTP, streptavidin-allophycocyanin, and streptavidin-europium. The assay was optimized for a HIV-RT high-throughput screen. Under optimized conditions, a signal-to-background ratio of approximately 10:1 and a Z' factor of 0.8 were obtained. The titration curves of several known HIV-RT inhibitors have been evaluated with this assay format. This HTRF format can be used for high-throughput assays with other nucleotide polymerases.
Collapse
Affiliation(s)
- J H Zhang
- DuPont Pharmaceuticals Research Laboratories, Wilmington, Delaware 19880-0400, USA.
| | | | | | | |
Collapse
|
9
|
André M, Morgeaux S, Fuchs F. Quantitative detection of RT activity by PERT assay: feasibility and limits to a standardized screening assay for human vaccines. Biologicals 2000; 28:67-80. [PMID: 10885614 DOI: 10.1006/biol.2000.0243] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The detection of adventitious retroviruses has always been critical for assessing the safety concerns associated with viral vaccines. Assays for the enzymatic activity of reverse transcriptase (RT) are used as general methods for the detection of both known and unknown retroviruses. Several studies using newly-developed ultrasensitive PCR-based RT assays reported RT activity in viral vaccines grown in chicken cells. Here, we have assessed the performances of such a PCR-based RT assay--PERT assay--for the quantitative detection of RT activity in vaccines. Sensitivity, linearity and reproducibility of the method were studied on purified RT and viral vaccines treated to release RT from potentially contaminant retroviruses. The level of RT activity detected in chicken cell-derived vaccines was higher for live attenuated vaccines compared to inactivated ones. Contrary to other studies, RT activity was found in some mammalian cell-derived vaccines. AZT-TP sensitivity of RT activities detected in these vaccines and discrimination between retroviral and RT-like activities was further investigated. Feasibility and limits of PERT assay as a broad-spectrum retroviruses detection method in vaccines are discussed.
Collapse
Affiliation(s)
- M André
- Agence Française de Sécurité Sanitaire des Produits de Santé, Direction des Laboratoires et des Contrôles, Unité de Contrôle des Médicaments Immunologiques, Lyon, France
| | | | | |
Collapse
|
10
|
Lovatt A, Black J, Galbraith D, Doherty I, Moran MW, Shepherd AJ, Griffen A, Bailey A, Wilson N, Smith KT. High throughput detection of retrovirus-associated reverse transcriptase using an improved fluorescent product enhanced reverse transcriptase assay and its comparison to conventional detection methods. J Virol Methods 1999; 82:185-200. [PMID: 10894635 DOI: 10.1016/s0166-0934(99)00111-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The development and application of a novel, sensitive TaqMan fluorescent probe-based product enhanced RT test (F-PERT) for the detection of retrovirus are described. The assay allows discrimination between the amplification signals generated by genuine positive signals that result from retroviral RT activity and the RT-like activity from DNA polymerases. The RT-like activity from DNA polymerases was suppressed by the addition of activated calf-thymus DNA with no reduction in the RT activity. A linear relationship between threshold cycle (C(T)) and the number of virus particles was demonstrated, allowing quantification of retroviruses in unknown samples. The F-PERT assay was able to detect a wide range of retroviral RT activities, including that from porcine endogenous retrovirus (PoERV), murine leukaemia virus (MLV), simian foamy virus (SFV), simian immunodeficiency virus (SIVmac) and squirrel monkey retrovirus (SMRV). The detection limit of SMRV, MLV and PoERV was approximately 100 virion particles and the test was able to detect at least 10(2) molecules of purified RT enzyme. RT activity was not detected in cellular lysates and supernatants from MRC-5, BT, VERO, or Raji cells, whereas RT activity was detected in C1271, Mus dunni, K-Balb, BHK-21, CHO-K1, SP2/0-Ag14 and NSO cell supernatants. RT activity was also detected in the Spodoptera cell line Sf9.
Collapse
|
11
|
Malmsten A, Ekstrand DH, Akerblom L, Gronowitz JS, Källander CF, Bendinelli M, Matteucci D. A colorimetric reverse transcriptase assay optimized for Moloney murine leukemia virus, and its use for characterization of reverse transcriptases of unknown identity. J Virol Methods 1998; 75:9-20. [PMID: 9820570 DOI: 10.1016/s0166-0934(98)00091-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A non-radioactive reverse transcriptase (RT) assay, reported as useful for lentivirus RTs, was optimized for the measurement of Moloney murine leukemia virus (MMuLV) RT. The optimized assay could detect 0.3 microU of MMuLV RT. The specificities of the MMuLV and lenti RT assays were demonstrated using the RTs of human immunodeficiency virus type 1, simian immunodeficiency virus, feline immunodeficiency virus (FIV), visna virus, human T-cell lymphotropic virus type 1, MMuLV and feline leukemia virus (FeLV). An RT activity blocking antibody (RTb-ab) assay was standardized for Mn2+ dependent MuLV-related RTs. The assay was used to demonstrate the distinct antigenic properties of RTs from mammalian MuLV-related retroviruses and lentiviruses. Cross-reactivity between MMuLV RTb-ab and FeLV RT but not between MMuLV RTb-ab and e.g. FIV RT was demonstrated. An RT activity found in the murine myeloma cell line SP2/0 was found to have similar assay preferences as MMuLV RT, and the MMuLV-RT hyperimmune sera reacted strongly against this RT, indicating the RT to be of MuLV-related etiology. The use of the RT and RTb-ab assays for detection and characterization of RTs of known or unknown identity is discussed.
Collapse
Affiliation(s)
- A Malmsten
- Department of Genetics and Pathology, Uppsala University, BMC, Sweden.
| | | | | | | | | | | | | |
Collapse
|
12
|
Saito T, Suzuki K, Imai M, Inaba Y. Measurement of reverse transcriptase of feline immunodeficiency virus by poly A-linked colorimetric assay. J Vet Med Sci 1997; 59:425-9. [PMID: 9234215 DOI: 10.1292/jvms.59.425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The method of the poly A-linked colorimetric reverse transcriptase assay (PAC-RTA) was developed and evaluated for the measurement of Mg(2+)-dependent reverse transcriptase (RT) activity of feline immunodeficiency virus (FIV). PAC-RTA was first evaluated for the detection of RT activity in the culture supernatant of FIV Petaluma strain. The detection limit of RT activity by PAC-RTA was about 10-fold better than that by the conventional non-radioisotopic RT assay kit. Then, PAC-RTA was evaluated for the indication of FIV isolation from cats naturally infected with FIV. FIV was isolated from peripheral blood mononuclear cells of 9 FIV-seropositive cats. The time course appearance of RT activity measured by PAC-RTA corresponded with the analysis of FIV antigen expression by indirect immunofluorescence. Finally, PAC-RTA evaluated the drug susceptibility of FIV. MYA-1 cells (feline T-lymphoblastoid cells) were infected with FIV and were cultured in the presence of various concentrations of anti-human immunodeficiency virus agents such as azidothymidine (AZT) or dextran sulfate. An inverse relationship between the RT activities and the concentrations of these agents in the culture supernatant was confirmed by PAC-RTA. PAC-RTA is easy to perform without using radioactive materials, and one plate can handle 96 samples at one time. By monitoring the RT activity, this assay is a useful method for FIV studies such as viral replication and drug susceptibility.
Collapse
Affiliation(s)
- T Saito
- Department of Virology, Kanagawa Prefectural Public Health Laboratory, Yokohama, Japan
| | | | | | | |
Collapse
|
13
|
Ekstrand DH, Böttiger D, Andersson H, Gronowitz JS, Clas FR. Reverse transcriptase and corresponding activity-blocking antibody for monitoring SIVsm infection in macaques. AIDS Res Hum Retroviruses 1997; 13:601-10. [PMID: 9135878 DOI: 10.1089/aid.1997.13.601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A nonradioactive reverse transcriptase (RT) assay was used to measure RT activity in serum during the viremia peak associated with primary infection and for measuring the generation and maintenance of RT activity-blocking antibody (RTb-ab) titers during and after seroconversion in SIV-infected macaques. The RT assay was compared to an antigen capture immunoassay designed for HIV-2/SIVsm and was found to be approximately 40 times more sensitive in detecting SIVsm in serum from infected macaques. The RT assay detected RT activity in serum corresponding to levels from 3 pg/ml. Earliest detection of viral replication using the RT assay was on day 6-8, with a peak at day 10 (up to 8000 pg/ml). The earliest detection of RTb-ab was seen on day 17-23, with established RTb-ab titers by day 29, followed by increasing titers of 15,000-120,000 by day 62-77. The usefulness of RT and RTb-ab for monitoring the course of SIV infection in monkey models is discussed.
Collapse
Affiliation(s)
- D H Ekstrand
- Department of Medical Genetics, Uppsala University, BMC, Sweden
| | | | | | | | | |
Collapse
|
14
|
Odawara F, Sano K, Otake T, Okubo S, Nakano T, Takasaki T, Ueba N, Misaki H, Nakai M. Human antibodies responsible for binding inhibition and polymerization inhibition of human immunodeficiency virus type 1 reverse transcriptase. J Immunol Methods 1996; 199:175-84. [PMID: 8982360 DOI: 10.1016/s0022-1759(96)00180-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Using a solid-phase non-radioisotopic (non-RI) reverse transcriptase (RT) assay, antibodies inhibiting human immunodeficiency virus type 1 (HIV-1) RT activity (RTI antibody) were investigated for their ability to inhibit binding of RT to a template-primer and DNA polymerization. The RTI antibody inhibited the binding of RT to the template-primer (BI antibody), and directly reacted with the RT-template-primer complex and inhibited enzymatic activity (PI antibody). The RTI antibody interfered with formation of the RT-template-primer complex suggesting that it recognized the antigenic site involved in template-primer binding of RT molecules. Since deoxynucleotide triphosphates (dNTPs) blocked inhibition of the RT activity by the PI antibody, the antigenic site recognized by the PI antibody may be closely related to the dNTP binding site. The seropositivities of the BI and PI antibodies were 84.6% and 91.2%, respectively, in HIV-1-infected individuals; healthy individuals, HTLV-I-positive individuals, autoimmune disease patients and leukemia patients were all seronegative. No significant correlation of residual RT activities was observed when BI and PI antibodies were compared (r = 0.688). It is possible that the epitopes recognized by the BI antibody differs from those recognized by the PI antibody. The assays described are able to detect BI and PI antibodies in the sera of HIV-1-infected individuals.
Collapse
Affiliation(s)
- F Odawara
- Department of Microbiology, Osaka Medical College, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Xu R, Gao Q, Wang S, Kan H, Sheng L, Li C, Zhang X, Xu G, Zhang K. Human acute myeloid leukemias may be etiologically associated with new human retroviral infection. Leuk Res 1996; 20:449-55. [PMID: 8709615 DOI: 10.1016/0145-2126(95)00120-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The etiology of human acute myeloid leukemias (AML) remains uncertain. In order to examine the possibility of retroviral etiology in AML, we determined retroviral antigens related to HTLV-I in leukemic cell samples from 32 AML cases and peripheral blood mononuclear cells (PBMNCs) from 20 healthy donors by D-IGSS with high sensitivity and specificity, reverse transcriptase (RT) activity by a simple and sensitive non-radioisotopic RT assay, and retroviral particles by electron microscopy. The HTLV-I-related antigens were detected in 50.0% (16/32) of fresh leukemic cell samples and 87.5% (28/32) of cultured leukemic cell samples. The HTLV-I-related antigen-positive cells in fresh and cultured leukemic samples were 10.2% and 52.8%, respectively. Both frequency and level of HTLV-I-related antigens in cultured samples were much higher than in fresh samples. In contrast, no HTLV-I-related antigens were found in normal hematopoietic cells from 20 healthy donors. Further study results show that RT activity was detected not only in HTLV-I-related antigen-positive samples, but was also well correlated with the level of HTLV-I-related antigens in these samples, and preferred Mn+2 to Mg+2 as a cation. Moreover, typical retroviral particles were localized in most cultured HTLV-I-related antigen-positive samples by immunoelectron microscope. These data suggest that human acute myeloid leukemias may be etiologically associated with new human retroviral infection.
Collapse
Affiliation(s)
- R Xu
- Hematology Research Division, Department of Medicine, 2nd Affiliated Hospital, Zhejiang Medical University, Hangzhou, People's Republic of China
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Sano K, Odawara F, Nakai M. Comparison of the sensitivities of two non-isotopic reverse transcriptase (RT) assays for human immunodeficiency virus type 1 RT. J Virol Methods 1996; 58:199-204. [PMID: 8783166 DOI: 10.1016/0166-0934(95)01992-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The sensitivities of two reverse transcriptase (RT) assays, an enzyme-linked oligonucleotide sorbent assay (ELOSA)-RT assay and a non-radioisotopic (non-RI) RT assay were compared. For measuring recombinant HIV-1 RT, the ELOSA-RT assay was 8 times less sensitive in dilution endpoint and 16 times less sensitive in measurement of RT from pelleted HIV-1 than the non-RI RT assay. Higher level of interference by an RNA-DNA hybrid observed in the former assay may indicate that the reduction in sensitivity was due to the presence of viral RNA in the sample of pelleted virus. The ELOSA-RT assay was interfered with to a great extent than the non-RI RT assay by fetal bovine serum and thus may be unsuitable for measuring RT from HIV-1 in a culture supernatant.
Collapse
Affiliation(s)
- K Sano
- Department of Microbiology, Osaka Medical College, Japan
| | | | | |
Collapse
|
17
|
Suzuki K, Saito T, Kondo M, Osanai M, Watanabe S, Kano T, Kano K, Imai M. Poly A-linked non-isotopic microtiter plate reverse transcriptase assay for sensitive detection of clinical human immunodeficiency virus isolates. J Virol Methods 1995; 55:347-56. [PMID: 8609200 DOI: 10.1016/0166-0934(95)00073-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A colorimetric reverse transcriptase assay (cRT assay) was developed for quantitative detection of HIV-1. In this format, reverse transcriptase incorporates biotin-labeled dUTP onto oligo-dT primers hybridized to poly A templates. The templates are covalently bound to the surface of microtiter wells. The amount of incorporated biotin-labeled dUTP is measured by binding horseradish peroxidase conjugated streptavidin, washing away unbound peroxidase, adding colorimetric substrate and then reading with a standard colorimetric reader. The sensitivity of the assay is very good. As little as 3 x 10(5) molecules of recombinant HIV-RT can be detected after 20 h of reaction time. Direct comparison using 3 cultured clinical isolates indicates that this level of detection is equivalent to the commercially available p24 antigen capture assay and the HIV-RNA assay based on branched DNA signal amplification. Other retroviruses, such as HIV-2 and feline immunodeficiency virus (FIV), can also be detected in this format. This non-isotopic assay is easy to perform and could provide a convenient and quantitative method for HIV study by monitoring reverse transcriptase, an essential activity in the infection process.
Collapse
Affiliation(s)
- K Suzuki
- Biomedical Research Center, Olympus Optical Co. Ltd., Tokyo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Sano K, Odawara F, Nakano T, Morimatsu S, Nakamura T, Saitoh Y, Jiang Y, Misaki H, Sakai Y, Nakai M. Comparable sensitivities for detection of HIV-1 reverse transcriptase (RT) and other polymerases by RT assays requiring no radioisotopic materials. J Virol Methods 1995; 53:235-44. [PMID: 7545693 DOI: 10.1016/0166-0934(95)00028-s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
An improved non-radioisotopic (Non-RI) reverse transcriptase (RT) assay with a template-primer-immobilized microtiter plate is described, which has greater sensitivity than the former Non-RI RT assay previously described. Non-RI and commercially available non-radioactive (Non-RA) RT assays were compared for their ability to detect various polymerases. Two RTs from Rous-associated virus 2 (RAV-2) and avian myeloblastosis virus (AMV), one polymerase from Escherichia coli (Pol-I) and one recombinant RT of human immunodeficiency virus type 1 (HIV-1) were assessed. Two HIV-1 samples in a culture supernatant and pelleted virion suspended in Triton X-100 solution were measured. The Non-RI RT assay was one hundred times more sensitive by RAV-2 and Pol-I polymerases, and one thousand times more sensitive by the Non-RA assay than by the AMV RT. The Non-RI RT assay was 10, 16 and 64 times more sensitive than the Non-RA assay for measuring recombinant HIV-1 RT, pelleted virus and virus suspended in culture medium, respectively. To explain the discrepancy, it is shown that free biotin, such as in culture medium, disturbs the assay system of the Non-RA RT assay, but not the Non-RI assay. The present assay can be used to clarify the inhibitory mechanism of an anti-HIV-1 substance.
Collapse
Affiliation(s)
- K Sano
- Department of Microbiology, Osaka Medical College, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Urabe T, Sano K, Nakano T, Odawara F, Lee MH, Otake T, Okubo S, Hayami M, Misaki H, Baba M. Differentiation between human immunodeficiency virus type 1 (HIV-1) and HIV-2 isolates by nonradioisotopic reverse transcriptase-typing assay. J Clin Microbiol 1994; 32:1870-5. [PMID: 7527425 PMCID: PMC263894 DOI: 10.1128/jcm.32.8.1870-1875.1994] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We tested whether human immunodeficiency virus type 1 (HIV-1) could be differentiated from HIV-2 by a reverse transcriptase (RT)-typing assay that measured the reduction of enzyme activity owing to specific antibody. RT-inhibiting antibody was examined for HIV type specificity by a new nonradioisotopic RT assay. Antibodies from four rabbits immunized with recombinant HIV-1 RT and from 23 HIV-1-seropositive individuals all specifically inhibited the enzyme activities of two HIV-1 strains (LAV-1 and GH-3), three zidovudine-resistant HIV-1 mutants, and a recombinant HIV-1 RT. However, none of these antisera affected the activities of six HIV-2 strains (GH-1, GH-2, GH-4, GH-5, GH-6, LAV-2ROD), Rous-associated virus type 2, and DNA polymerase I from Escherichia coli. In contrast, HIV-2 antibody from a rabbit immunized with disrupted GH-1 virions blocked the enzyme activities of the six HIV-2 strains but not those of the three HIV-1 strains, Rous-associated virus type 2, or DNA polymerase I. These results indicate that the antigenic domains of HIV-1 and HIV-2 RTs recognized by their inhibiting antibodies are distinct from each other and are highly conserved. Clinical HIV isolates from 18 HIV-1-seropositive individuals and 3 HIV-2-seropositive Ghanaian individuals were identified as HIV-1 and HIV-2, respectively, by the nonradioisotopic RT-typing assay.
Collapse
Affiliation(s)
- T Urabe
- Department of Microbiology, Osaka Medical College, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Suzuki K, Craddock BP, Okamoto N, Kano T, Steigbigel RT. Poly A-linked colorimetric microtiter plate assay for HIV reverse transcriptase. J Virol Methods 1993; 44:189-98. [PMID: 7505283 DOI: 10.1016/0166-0934(93)90054-u] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
An assay for detection of the reverse transcriptase (RT) of the human immunodeficiency virus (HIV) was developed using poly A linked to microtiter plate with colorimetric detection of incorporated biotin deoxyuridine triphosphate (biotin-dUTP). During the RT reaction, biotin-dUTP was incorporated into oligodeoxythymidylic acid (oligo-dT) which had been hybridized with poly A. At the detection step, horseradish peroxidase conjugated streptavidin was added, followed by the reaction of a colorimetric substrate for this enzyme. This method was contrasted with the two standard isotopic RT assays. There was excellent correlation between the colorimetric RT assay and each of two isotopic RT assays for both detection and quantification of avian myoblastosis virus reverse transcriptase (AMV-RT) and of HIV RT in human lymphocytes infected in vitro with HIV-1. The total assay required for performing the colorimetric assay, including the RT reaction, was 40 min.
Collapse
Affiliation(s)
- K Suzuki
- Biomedical Research Center, Olympus Corporation, East Setauket, NY
| | | | | | | | | |
Collapse
|