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Lim F.,Autonomous University of Madrid | Khalique H.,Autonomous University of Madrid | Ventosa M.,Autonomous University of Madrid | Baldo A.,Scientific Institute of Public Health WIV ISP
Current Gene Therapy | Year: 2013

The majority of humans have been infected with Herpes Simplex Virus Type 1 (HSV-1) and harbor its viral DNA in the latent form within neurons for lifetime. This, combined with the absence of serious adverse effects due to HSV-1 derived vectors in clinical trials so far, highlight the potential to use this virus to develop neuronal gene transfer vectors which are transparent to the host, allowing the effects of the transgene to act without interference from the transfer system eg., for functional genomics in basic neuroscience or gene therapy of neurological disorders. On the other hand, other HSV-1 derived vectors which also have a promising perspective in the clinic, are designed to have enhanced cytotoxicity in certain cell types, as in the case of oncolytic vectors. Understanding virus-host interactions is fundamental not only to the success of these gene therapy vectors but also with respect to identifying and minimizing biohazards associated with their use. In this review we discuss characteristics of HSV-1 and gene therapy vectors derived from this virus which are useful to consider in the context of biosafety risk assessment and risk management. © 2013 Bentham Science Publishers.

Broeders S.,Scientific Institute of Public Health WIV ISP | Huber I.,Bavarian Health and Food Safety Authority LGL | Grohmann L.,Federal Office of Consumer Protection and Food Safety BVL | Berben G.,Walloon Agricultural Research Center | And 5 more authors.
Trends in Food Science and Technology | Year: 2014

As for many areas of molecular testing, detection of Genetically Modified Organisms (GMO) relies on the real-time Polymerase Chain Reaction (qPCR) technology. Due to the increasing number of GMO, a screening approach using qualitative screening methods has become an integrated part of GMO detection. However, specific guidelines for the validation of these methods are lacking. Here, a pragmatic approach to conduct in-house and inter-laboratory validation studies for GMO screening methods, is proposed. Such guidelines could be adapted to other areas where qualitative qPCR methods are used for molecular testing allowing to implement easily a more reliable screening phase where necessary. © 2014 Elsevier Ltd.

Baldo A.,Scientific Institute of Public Health WIV ISP | van den Akker E.,National Institute for Public Health and the Environment RIVM | Bergmans H.E.,National Institute for Public Health and the Environment RIVM | Lim F.,Autonomous University of Madrid | Pauwels K.,Scientific Institute of Public Health WIV ISP
Current Gene Therapy | Year: 2013

This introductory paper gathers general considerations on the biosafety of virus-derived vectors that are used in human gene therapy and/or vaccination. The importance to assess the potential risks for human health and the environment related to the use of genetically modified organisms (GMO) in this case genetically modified viral vectors is highlighted by several examples. This environmental risk assessment is one of the requirements within the European regulatory framework covering the conduct of clinical trials using GMO. Risk assessment methodologies for the environmental risk assessment of genetically modified virus-derived vectors have been developed. © 2013 Bentham Science Publishers.

Huygen K.,Scientific Institute of Public Health WIV ISP | Cabore R.N.,Scientific Institute of Public Health WIV ISP | Maertens K.,University of Antwerp | Van Damme P.,University of Antwerp | Leuridan E.,University of Antwerp
Vaccine | Year: 2015

Vaccination of pregnant women is recommended for some infectious diseases in order to protect both women and offspring through high titres of maternal IgG antibodies. Less is known on the triggering of cellular immune responses by vaccines administered during pregnancy. In an ongoing study on maternal pertussis vaccination (2012-2014) 18 pregnant women were vaccinated with a tetanus-diphtheria-acellular pertussis (Tdap) containing vaccine (Boostrix®) during the third pregnancy trimester. Sixteen age-matched nonpregnant women received the same vaccine in the same time period. A blood sample was taken at the moment of, but before vaccination and one month and one year after vaccination. Anti-Pertussis Toxin (PT), filamentous hemagglutinin (FHA), pertactin (Prn), tetanus toxin (TT) and diphtheria toxin (DT) antibodies were measured by ELISA. Cellular immune responses were analyzed using a diluted whole blood assay, measuring proliferation, and cytokine release in response to vaccine antigens PT, FHA, TT, and to pokeweed mitogen (PWM) as polyclonal stimulus. Antibody levels to all five vaccine components increased significantly and to the same extent after vaccination in pregnant and nonpregnant women. One year after vaccination, antibody titres had decreased particularly to PT, but they were still significantly higher to all antigens than before vaccination. In contrast, proliferative and IFN-γ responses were increased to TT, PT, and FHA in nonpregnant women one month after vaccination, whereas in pregnant women only TT specific T cell responses were increased and to a lesser extent than in the control group. One year after vaccination, cellular responses equaled the baseline levels detected prior to vaccination in both groups. In conclusion, a Tdap vaccination can increase vaccine specific IgG antibodies to the same extent in pregnant and in nonpregnant women, whereas the stimulation of vaccine specific Th1 type cellular immune responses with this acellular vaccine is transient and impaired during pregnancy. © 2015 Elsevier Ltd.

Aryan E.,Mashhad University of Medical Sciences | Makvandi M.,Ahvaz Jundishapur University of Medical Sciences | Farajzadeh A.,Ahvaz Jundishapur University of Medical Sciences | Huygen K.,Scientific Institute of Public Health WIV ISP | And 4 more authors.
Journal of Infection | Year: 2013

Objectives: A fundamental to global tuberculosis (TB) control is timely and accurate diagnosis of infectious cases of the disease. Among various methods, techniques based on nucleic acid amplification are the ones with promising prospects. The present study evaluates the diagnostic value of the recently developed IS. 6110-based loop-mediated isothermal amplification (LAMP) for detection of Mycobacterium tuberculosis complex (MTBC) in sputum specimens. Methods: In this cross-sectional study (2008-2009), IS. 6110-LAMP was evaluated on 101 sputum specimens from 93 highly suspected TB patients and compared to Amplicor MTB test and in-house IS. 6110-PCR and -nested PCR assays. Culture results or clinical recovery following anti-TB therapy was considered as a reference to prove the TB cases. Results: The overall sensitivity of IS. 6110-LAMP, Amplicor, nPCR, and PCR were respectively 89.6% (69/77 specimens; 95% confidence interval [CI], 80.5-95.4%), 76.6% (59/77 specimens; CI, 65.6-85.5%), 79.2% (61/77 specimens; CI, 68.5-87.6%) and 59.7% (46/77 specimens; CI, 47.9-70.8%). The specificity and positive predictive value (PPV) were 100% for all the tests, and the negative predictive value (NPV) of IS. 6110-LAMP, Amplicor, nPCR, and PCR were respectively 75%, 57.1%, 60%, and 43.6%. There was an excellent overall agreement between LAMP and nPCR (. k 0.828), and between LAMP and Amplicor (. k 0.746), in addition to a better tolerance of IS. 6110-LAMP to inhibitors present in clinical specimens. Conclusion: The better diagnostic performance of IS. 6110-LAMP compared to Amplicor (. p = 0.009), nPCR (p = 0.013) and PCR (. p < 0.0001) besides its rapidity, simplicity, and cost-effectiveness makes it a valuable method for the detection of MTBC in clinical samples, particularly in resource-limited settings. © 2013 The British Infection Association.

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