The research described in this Thesis was aimed at designing and synthesizing nature-inspired compounds as part of TB vaccine discovery. A variety of synthetic analogues of mycobacterial cell wall... Show moreThe research described in this Thesis was aimed at designing and synthesizing nature-inspired compounds as part of TB vaccine discovery. A variety of synthetic analogues of mycobacterial cell wall components, from peptide and glycolipid antigens to glycolipid PAMPs has been accessed. Evaluation of the immune stimulatory activity of the novel compounds in combination with preliminary immunization studies in vivo, suggested the potential of selected synthetic conjugates as single molecule vaccines against TB. Further research is needed to verify the efficacy of these vaccine modalities. Show less
Lau, S.P.; Land, F.R. van 't; Burg, S.H. van der; Homs, M.Y.V.; Lolkema, M.P.; Aerts, J.G.J.V.; Eijck, C.H.J. van 2022
Introduction The prognosis of patients with advanced pancreatic ductal adenocarcinoma (PDAC) is dismal and conventional chemotherapy treatment delivers limited survival improvement. Immunotherapy... Show moreIntroduction The prognosis of patients with advanced pancreatic ductal adenocarcinoma (PDAC) is dismal and conventional chemotherapy treatment delivers limited survival improvement. Immunotherapy may complement our current treatment strategies. We previously demonstrated that the combination of an allogeneic tumour-lysate dendritic cell (DC) vaccine with an anti-CD40 agonistic antibody resulted in robust antitumour responses with survival benefit in a murine PDAC model. In the Rotterdam PancrEAtic Cancer Vaccination-2 trial, we aim to translate our findings into patients. This study will determine the safety of DC/anti-CD40 agonistic antibody combination treatment, and treatment-induced tumour-specific immunological responses. Methods and analysis In this open-label, single-centre (Erasmus Univsersity Medical Center, Rotterdam, Netherlands), single-arm, phase I dose finding study, adult patients with metastatic pancreatic cancer with progressive disease after FOLFIRINOX chemotherapy will receive monocyte-derived DCs loaded with an allogeneic tumour lysate in conjunction with a CD40 agonistic antibody. This combination-immunotherapy regimen will be administered three times every 2 weeks, and booster treatments will be given after 3 and 6 months following the third injection. A minimum of 12 and a maximum of 18 patients will be included. The primary endpoint is safety and tolerability of the combination immunotherapy. To determine the maximum tolerated dose, DCs will be given at a fixed dosage and anti-CD40 agonist in a traditional 3+3 dose-escalation design. Secondary endpoints include radiographic response according to the RECIST (V.1.1) and iRECIST criteria, and the detection of antitumour specific immune responses. Ethics and dissemination The Central Committee on Research Involving Human Subjects (CCMO; NL76592.000.21) and the Medical Ethics Committee (METC; MEC-2021-0566) of the Erasmus M.C. University Medical Center Rotterdam approved the conduct of the trial. Written informed consent will be required for all participants. The results of the trial will be submitted for publication in a peer-reviewed scientific journal. Show less
The chemical and structural heterogeneity of toxoid vaccines makes their analysis challenging. However, detailed insights on a molecular level can be obtained by mass spectrometry. Our initial... Show moreThe chemical and structural heterogeneity of toxoid vaccines makes their analysis challenging. However, detailed insights on a molecular level can be obtained by mass spectrometry. Our initial focus was the identification of formaldehyde-induced modifications in diphtheria toxin, which is described in Chapter 2. Subsequently, the methods described in Chapter 2 were applied to study what effects formaldehyde-induced modifications on model proteins have on their susceptibility to enzymatic proteolysis (Chapter 3). During the analysis of these model proteins, unknown formaldehyde-induced modifications were observed. The structural elucidation of these modifications, the discovery of a new type of crosslinks and various other subsequent reaction products are described in Chapter 4. The degradomics analysis described in Chapter 3 was applied to tetanus toxoids to distinguish heat-denaturated toxoids from their original state (Chapter 5). In order to reduce the analysis time and further improve the degradomics approach, an optimized strategy using Tandem Mass Tag multiplexing for the relative quantification of peptides was developed for the analysis of diphtheria toxoids (Chapter 6). Finally, Chapter 7 provides a brief discussion on the results presented in this thesis and offers some perspectives on implementation of the findings for toxoid vaccine development, quality control and further research. Show less
This thesis contains a variety of information about the natural and vaccine induced immunity against the human papillomavirus. The spontaneously induced HPV-specific humoral response after... Show moreThis thesis contains a variety of information about the natural and vaccine induced immunity against the human papillomavirus. The spontaneously induced HPV-specific humoral response after infection was assessed in population-based studies. The vaccine-induced changes in HPV-seroprevalence among the HPV unvaccinated Dutch population aged 0-89 years, where we compared the HPV-seroprevalence before the introduction of the HPV vaccine with data of approximately six years post-implementation of the national HPV vaccination program. Also, the HPV immune status of the Dutch Caribbean population just after introduction of HPV vaccination was determined. Moreover, the longitudinal relation between the hr-HPV antibody levels and the prevalence of HPV infections in three-dose vaccinated girls were studied. And more insight was gained into humoral and cellular immune responses after just a one-dose of the HPV vaccine. At last, the kinetics of innate and adaptive immune responses directly after vaccination different HPV vaccines were investigated. In the coming years some important changes are expected regarding HPV screening and vaccination. The effectiveness of the one-dose schedule will become clear as clinical trials end. In the Netherlands, a sex-neutral vaccination will be implemented soon. These changes will need to be monitored to provide scientific answers about the effectiveness and immunogenicity. Show less
This thesis describes the development of improved formulations and alternative delivery strategies for polio vaccination. A new generation of IPV should not only be affordable and safe to... Show moreThis thesis describes the development of improved formulations and alternative delivery strategies for polio vaccination. A new generation of IPV should not only be affordable and safe to produce, but preferably should also induce mucosal immunity, remain stable at unrefrigerated conditions, and be easy to administer. This is also important with regard to stockpiling and outbreak management in the period towards and beyond polio eradication. Solid dosage forms that have improved thermostability, like biodegradable Bioneedles comprising lyophilized IPV or polymer-based oral films, would be favorable to reach remote areas in developing countries for which proper logistics are not available. Replacing the currently used polio vaccines with a thermostable vaccine may yield significant cost savings. Furthermore, vaccination via mucosal routes showed to have important advantages over conventional intramuscular vaccination using needle and syringes. Show less
Seasonal influenza epidemics lead to severe flu in 3 to 5 million individuals and emerging pandemic influenza strains pose an even greater threat to society. We describe a clinical trial in which... Show moreSeasonal influenza epidemics lead to severe flu in 3 to 5 million individuals and emerging pandemic influenza strains pose an even greater threat to society. We describe a clinical trial in which vaccine-specific responses were measured during two consecutive influenza seasons, including the season in which the 2009 pandemic virus emerged, and showed that these vaccines induced both humoral and cellular responses. However, these responses are unlikely to be protective against newly emerging strains, due to the variable nature of influenza virus. Therefore, the other chapters in this thesis describe concepts within peptide-based vaccination strategies, which is one method to induce responses to highly conserved sequences of influenza virus. We evaluated a concept based on long peptides directed to highly conserved B and T cell epitopes and showed that this vaccine was capable of inducing both humoral and cellular immune responses. Furthermore, the vaccine provided partial protection against infection in an animal model. We also described another successful strategy to enhance the immunogenicity of minimal peptides by modification of these peptides and proceeded with formulations to improve delivery of these minimal peptides. Altogether, the findings in this thesis may contribute to the development of the next generation influenza vaccines. Show less
The Flavivirus genus contains nearly 80 viruses, including many important human pathogens such as dengue virus, yellow fever virus, West Nile virus and tick-borne encephalitis virus. To reduce and... Show moreThe Flavivirus genus contains nearly 80 viruses, including many important human pathogens such as dengue virus, yellow fever virus, West Nile virus and tick-borne encephalitis virus. To reduce and prevent the impact of flavivirus infection on society, vaccines and effective therapies are required. However, this can only be achieved by increasing our knowledge regarding fundamental aspects of the molecular biology of flaviviruses and a better understanding of the interactions between the virus, the host and the vector. Flaviviruses are small, enveloped viruses containing a positive single-stranded RNA genome of approximately 11 kb with a 5__-cap structure and a non-polyadenylated 3__ end. The flavivirus 3__ untranslated region (UTR) is known to be important for replication and translation of the viral genome. The 3__ UTR contains well conserved RNA sequences and is predicted to fold into a highly complex structure involving several stem-loops and RNA pseudoknots. Some of these motifs and structures have been studied in detail and attributed a biological function, although only a small fraction of the predicted structures has been confirmed by probing. The aim of this thesis was to characterize and determine the biological function of RNA elements present in the flavivirus 3__ UTR. Show less
