| 1. |
- Bindra, Amarinder, et al.
(författare)
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Search for DNA of exogenous mouse mammary tumor virus-related virus in human breast cancer samples
- 2007
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Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 88, s. 1806-1809
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Tidskriftsartikel (refereegranskat)abstract
- Earlier reports of a human exogenous retrovirus (HMTV) related closely to mouse mammary tumor virus (MMTV) led us to search for these viral sequences in breast cancer tissues and normal tissues. A real-time PCR was developed based on MMTV and published HMTV envelope sequences. The real-time PCR method can detect one to ten copies of MMTV target DNA. Tissue samples were collected prospectively from 18 breast cancer patients and 11 non-malignant control cases, as well as peripheral blood leukocytes from the same women. Despite the high sensitivity of the real-time PCR method used, none of the samples were positive for HMTV DNA or RNA. The absence of HMTV DNA in both breast cancer samples and controls indicates either that the concentration of putative HMTV DNA in the breast cancers was too low for detection or that it did not exist there.
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| 2. |
- Muradrasoli, Shaman, et al.
(författare)
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Broadly targeted multiprobe QPCR for detection of coronaviruses : Coronavirus is common among mallard ducks (Anas platyrhynchos)
- 2009
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Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 159:2, s. 277-287
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Tidskriftsartikel (refereegranskat)abstract
- Coronaviruses (CoV) can cause trivial or fatal disease in humans and in animals. Detection methods for a wide range of CoVs are needed, to understand viral evolution, host range, transmission and maintenance in reservoirs. A new concept, "Multiprobe QPCR", which uses a balanced mixture of competing discrete non- or moderately degenerated nuclease degradable (TaqMan((R))) probes was employed. It provides a broadly targeted and rational single tube real-time reverse transcription PCR ("NQPCR") for the generic detection and discovery of CoV. Degenerate primers, previously published, and the new probes, were from a conserved stretch of open reading frame 1b, encoding the replicase. This multiprobe design reduced the degree of probe degeneration, which otherwise decreases the sensitivity, and allowed a preliminary classification of the amplified sequence directly from the QPCR trace. The split probe strategy allowed detection of down to 10 viral nucleic acid equivalents of CoV from all known CoV groups. Evaluation was with reference CoV strains, synthetic targets, human respiratory samples and avian fecal samples. Infectious-Bronchitis-Virus (IBV)-related variants were found in seven of 35 sample pools, from 100 wild mallards (Anas platyrhynchos). Ducks may spread and harbour CoVs. NQPCR can detect a wide range of CoVs, as illustrated for humans and ducks.
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| 3. |
- Muradrasoli, Shaman, 1972-
(författare)
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Detection and Quantification of Variable Viral RNA by Real-Time PCR Assays
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As the area of nucleic acid based technologies develops, so will our understanding of how structural variations in DNA and RNA pathogens are associated with disease. The overall goal of this thesis is the development of broadly targeted measurement techniques for variable viral RNA by Real-Time PCR (here referred to as quantitative reverse transcriptase PCR, QRT-PCR). In papers I & II, broadly targeted and specific QRT-PCRs were used to study expression of endogenous and exogenous betaretrovirus sequences in human tissues. Results from human tissues demonstrated endogenous betaretrovirus expression in a tissue-specific manner, highest in reproductive tissues. Despite the high sensitivity, no exogenous betaretrovirus was found in human breast cancer samples. The limits of primer and probe degeneracy for detection of a diverse set of retroviral sequences was evaluated. These methods are useful for further investigations on the pathophysiological contribution(s) of endogenous betaretrovirus and to investigate whether an exogenous betaretrovirus is involved in human breast cancer. In papers III & IV, we developed and applied broadly targeted one-step QRT-PCRs for influenza viruses and coronaviruses. In addition to the generic primers, two novel probe design strategies were used in order to be able to broadly amplify these diverse sets of viruses: A triplex system for simultaneous detection and quantification of influenza A, B and C (3QRT-PCR and further developed 3QRT-PCR-MegB; where MegB stands for MegaBeacon) based on TaqMan® and MegB probes, and a pan-CoV QRT-PCR, based on three TaqMan® probes i.e., degeneracy was distributed on three probes. Probe fault tolerance was thus increased in two ways, either with short probes with/without locked nucleic acid (LNA) nucleotides concentrated to conserved stretches, or with long probes (MegB), compensating mismatching positions with many matching ones. Clinical samples, negative by antigen detection with immunofluorescence (IFA), were influenza A positive with 3QPCR-MegB. Avian pooled samples, negative with an earlier pan-CoV QPCR, came out positive with the triple-probe system. Assay evaluation with clinical samples and reference strains revealed good clinical diagnostic potential. Thus, the thesis describes several strategies to counteract sequence variation of RNA viruses and describes a set of broadly targeted QRT-PCRs useful for scientific screening or diagnostics of betaretroviruses and respiratory viruses.
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| 4. |
- Muradrasoli, Shaman, et al.
(författare)
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Development of real-time PCRs for detection and quantitation of human MMTV-Iike (HML) sequences HML expression in human tissues
- 2006
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Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 136:1-2, s. 83-92
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Tidskriftsartikel (refereegranskat)abstract
- The human genome contains around 1000 betaretrovirus-like copies, human mouse mammary tumour virus (MMTV)-like (HML) groups 1 - 10, also referred to as human endogenous retroviruts "HERV-K". Despite many efforts, it is not established whether betaretroviruses, exo- or endogenous, are involved in the etiology of breast cancer, or other cancer diseases, in humans. Quantitative real-time PCR (QPCR) TaqMan((R))-based assays for HML groups 1-7, targeting the conserved reverse transcriptase (RT) and integrase (IN) domains of the pol gene were designed. Plasmids containing the entire pol gene of HML 1-7 were used as standards. The RT and IN based QPCRs could detect 10(0)-10(3) copies per PCR reaction of the plasmids. However, not all plasmids gave a signal in both RT and IN QPCRs, probably due to mismatches. Furthermore, RT and IN based HML6 specific QPCRs were developed. They were specific for amplification of transcripts for the whole HML6 group. The methods allow the monitoring in body fluids and tissues of expression of a wide range of betaretrovirus-like sequences. Betaretrovirus-like RNA was studied in normal human tissues and of HML6 in brains of multiple sclerosis (MS) patients. Brain, adrenal gland and testis had a high betaretrovirus-like expression. Multiple sclerosis plaques contained the same HML6 RNA concentration as control tissue. These assays are expected to enhance studies on involvement of betaretroviruses in physiology and disease.
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