http://hdl.handle.net/10029/4903 Sun, 26 May 2013 01:18:31 GMT 2013-05-26T01:18:31Z http://hdl.handle.net/10029/8396 Title: Stable isotope tagging of epitopes: a highly selective strategy for the identification of major histocompatibility complex class I-associated peptides induced upon viral infection. Authors: Meiring, Hugo D; Soethout, Ernst C; Poelen, Martien C M; Mooibroek, Dennis; Hoogerbrugge, Ronald; Timmermans, Hans; Boog, Claire J; Heck, Albert J R; Jong, Ad P J M de; Els, Cécile A C M van Abstract: Identification of peptides presented in major histocompatibility complex (MHC) class I molecules after viral infection is of strategic importance for vaccine development. Until recently, mass spectrometric identification of virus-induced peptides was based on comparative analysis of peptide pools isolated from uninfected and virus-infected cells. Here we report on a powerful strategy aiming at the rapid, unambiguous identification of naturally processed MHC class I-associated peptides, which are induced by viral infection. The methodology, stable isotope tagging of epitopes (SITE), is based on metabolic labeling of endogenously synthesized proteins during infection. This is accomplished by culturing virus-infected cells with stable isotope-labeled amino acids that are expected to be anchor residues (i.e. residues of the peptide that have amino acid side chains that bind into pockets lining the peptide-binding groove of the MHC class I molecule) for the human leukocyte antigen allele of interest. Subsequently these cells are mixed with an equal number of non-infected cells, which are cultured in normal medium. Finally peptides are acid-eluted from immunoprecipitated MHC molecules and subjected to two-dimensional nanoscale LC-MS analysis. Virus-induced peptides are identified through computer-assisted detection of characteristic, binomially distributed ratios of labeled and unlabeled molecules. Using this approach we identified novel measles virus and respiratory syncytial virus epitopes as well as infection-induced self-peptides in several cell types, showing that SITE is a unique and versatile method for unequivocal identification of disease-related MHC class I epitopes. Mon, 01 May 2006 00:00:00 GMT http://hdl.handle.net/10029/8396 2006-05-01T00:00:00Z http://hdl.handle.net/10029/6786 Title: Long-term protection against carriage of hepatitis B virus after infant vaccination. Authors: Sande, Marianne A B van der; Waight, P; Mendy, M; Rayco-Solon, P; Hutt, P; Fulford, T; Doherty, C; McConkey, S J; Jeffries, D; Hall, A J; Whittle, H C Abstract: BACKGROUND: Carriage of hepatitis B virus (HBV) is a major risk factor for liver cirrhosis and hepatocellular carcinoma. Infant vaccination has been effective in preventing horizontal transmission during early childhood. It is unknown whether protection is maintained into early adulthood. METHODS: In 1984, early childhood vaccination was introduced in 2 rural Gambian villages. In 2003, serological assessment of 81.5% of 1,350 eligible participants 1-24 years old was done, to determine vaccine efficacy against infection and carriage. RESULTS: Overall vaccine efficacy against infection and carriage was 83.4% (95% confidence interval [CI], 79.8%-86.6%) and 96.5% (85% CI, 93.9%-98.9%), respectively. Vaccine efficacy against infection was similar when restricted to primary responders (85.3%), but a significant effect of peak antibody concentration was found. Both vaccine efficacy and levels of hepatitis B surface antibody (anti-HBs) decreased with age, resulting in a vaccine efficacy against infection and carriage among 20-24-year-old participants of 70.9% (95% CI, 60.4%-80.5%) and 91.1% (95% CI, 75.8%-100%), respectively. Fifteen years after vaccination, fewer than half of the vaccinees had detectable anti-HBs. The prevalence of carriage in the unvaccinated population was similar to the prevalence 20 years earlier. CONCLUSIONS: HBV vaccination early during life can provide long-lasting protection against carriage, despite decreasing antibody levels. The role played by subclinical boosting and the necessity of a booster need to be evaluated. Thu, 01 Jun 2006 00:00:00 GMT http://hdl.handle.net/10029/6786 2006-06-01T00:00:00Z http://hdl.handle.net/10029/6776 Title: Preclinical and clinical safety studies on DNA vaccines. Authors: Schalk, Johanna A C; Mooi, Frits R; Berbers, Guy A M; Aerts, Leon A G J M van; Ovelgönne, Hans; Kimman, Tjeerd G Abstract: DNA vaccines are based on the transfer of genetic material, encoding an antigen, to the cells of the vaccine recipient. Despite high expectations of DNA vaccines as a result of promising preclinical data their clinical utility remains unproven. However, much data is gathered in preclinical and clinical studies about the safety of DNA vaccines. Here we review current knowledge about the safety of DNA vaccines. Safety concerns of DNA vaccines relate to genetic, immunologic, toxic, and environmental effects. In this review we provide an overview of findings related to the safety of DNA vaccines, obtained so far. We conclude that the potential risks of DNA vaccines are minimal. However, their safety issues may differ case-by-case, and they should be treated accordingly. Wed, 03 Jan 2007 12:37:38 GMT http://hdl.handle.net/10029/6776 2007-01-03T12:37:38Z http://hdl.handle.net/10029/6691 Title: Use of oseltamivir in Dutch nursing homes during the 2004-2005 influenza season. Authors: Sande, Marianne A B van der; Ruijs, Wilhelmina L M; Meijer, Adam; Cools, Herman J M; Plas, Simone M van der Abstract: To assess the implementation of guidelines for using neuraminidase inhibitors in the control of influenza outbreaks in Dutch nursing homes, data were collected on prophylactic and therapeutic use of anti-viral medication, indications for use and criteria for prescribing, based on experiences during the influenza season 2004-2005 in a retrospective cross-sectional survey among Dutch nursing homes after the 2004-2005 season. Ninety/194 (49%) participating nursing homes reported an outbreak of influenza-like illness; in 57/194 (29%) influenza was laboratory confirmed. In 37/57 homes (65%) oseltamivir had been used as prophylaxis. Prophylactic use was extended to all residents and staff in 6/37 (16%) of homes, but limited in the others. In 9/37 (24%) no staff were issued prophylaxis. Among clinicians with laboratory confirmed influenza, 41/46 (89%) had used oseltamivir therapeutically. Main reasons for not prescribing oseltamivir for prophylaxis and/or therapy were lack of scientific evidence, high costs, and absent or delayed laboratory confirmation. Logistical bottlenecks in diagnosis, cost-effectiveness concerns, and lack of an evidence-base hamper full integration in policy and should be addressed. Fri, 10 Nov 2006 00:00:00 GMT http://hdl.handle.net/10029/6691 2006-11-10T00:00:00Z