{"id":9505,"date":"2026-04-08T09:08:27","date_gmt":"2026-04-08T09:08:27","guid":{"rendered":"https:\/\/www.proefschriftmaken.nl\/portfolio\/michelle-klouwens\/"},"modified":"2026-04-23T08:08:10","modified_gmt":"2026-04-23T08:08:10","slug":"michelle-klouwens","status":"publish","type":"us_portfolio","link":"https:\/\/www.proefschriftmaken.nl\/en\/portfolio\/michelle-klouwens\/","title":{"rendered":"Michelle Klouwens"},"content":{"rendered":"","protected":false},"excerpt":{"rendered":"","protected":false},"author":8,"featured_media":13263,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"us_portfolio_category":[45],"class_list":["post-9505","us_portfolio","type-us_portfolio","status-publish","has-post-thumbnail","hentry","us_portfolio_category-new-template"],"acf":{"naam_van_het_proefschift":"Vaccines to prevent Lyme Borreliosis","samenvatting":"Lyme borreliose is de meest voorkomende door teken overdraagbare aandoening in Europa en Noord-Amerika. Borrelia burgdorferi sensu lato (sl), de bacterie die Lyme borreliose veroorzaakt, wordt overgebracht door zogenaamde harde Ixodes teken. Er bestaat momenteel geen humaan vaccin tegen Lyme borreliose. Het meeste onderzoek naar preventieve strategie\u00ebn voor Lyme borreliose richt zich op recombinante eiwitvaccins, vooral omdat deze vaccins succesvol zijn gebleken in andere toepassingen en ook voor de preventie van Lyme borreliose in het verleden. In dit proefschrift onderzochten we alternatieve vaccinatiestrategie\u00ebn en potenti\u00eble vaccinkandidaten van zowel de Ixodes tekenvector als van B. burgdorferi sl.\n\nWe beginnen met een inleiding over Lyme borreliose en een beschrijving van de betrokken vector en van het pathogeen in hoofdstuk 1. We geven een overzicht van preventiemaatregelen tegen Lyme borreliose met de nadruk op anti-teken en anti-Borrelia vaccins.\n\nIn hoofdstuk 2 beschrijven we de immuunrespons van de gastheer tegen zowel de teek als tegen het pathogeen en geven we een uitgebreid overzicht van de vele factoren waarmee rekening moet worden gehouden bij het zoeken naar een effectief anti-tekenvaccin. Verder bespreken we de geschiedenis van het onderzoek naar anti-tekenvaccins en spreken we over verworven tekenresistentie (ATR), de rationale achter de zoektocht naar anti-tekenvaccins. Het laatste deel van dit hoofdstuk gaat in detail in op een bestaand veterinair anti-teken vaccin tegen een andere tekensoort, maar geeft ook een overzicht van experimentele vaccinkandidaten tegen Ixodes teken waar op dit moment onderzoek naar gedaan wordt.\n\nHoofdstuk 3 gaat verder met de beschrijving van het DNA tattoo vaccinatie model en het gebruik van deze techniek om op eenvoudige wijze tekenantigenen te screenen op hun werkzaamheid als DNA vaccin in een muis\u2013teek\u2013B. burgdorferi infectiemodel. We hebben muizen ge\u00efmmuniseerd met DNA-vaccins die coderen voor bekende tekeneiwitten\u2013Salp15, tHRF, TSLPI en TIX-5\u2013waarvan eerder is beschreven dat ze, wanneer gebruikt als experimentele, op recombinante eiwitten gebaseerde vaccins, interfereren met voeding van de teek of met Borrelia transmissie. Aangezien eerder is aangetoond dat DNA vaccinatie met het Borrelia eiwit OspC bescherming biedt tegen homologe B. burgdorferi sl expositie wanneer deze middels injectie subcutaan worden toegediend, hebben wij besloten OspC als controle te gebruiken. In de huidige studie hebben we aangetoond dat het OspC DNA vaccin in staat was een IgG respons te induceren welke vergelijkbaar was met die van recombinant OspC en ook een vrijwel volledige bescherming liet zien tegen B. burgdorferi ss-infectie door tekenbeet. De DNA vaccins van de tekenantigenen lieten slechts een lage tot matige antistofrespons zien en deze vaccins boden ook geen bescherming tegen","summary":"A novel strategy for an anti-Borrelia vaccine is described in chapter 4, making use of Outer Membrane Vesicles (OMVs), nanostructures that bud naturally from the outer membrane of gram-negative bacteria as a response to stress and to adapt in order to survive. OMVs have great immunogenic properties and can function both as adjuvant and as delivery vehicle, as antigens from other pathogens can be expressed on their surface. OMV-based vaccines could also be brought to the market relatively easily, as an OMV-based vaccine against meningococcal disease is already available for human use. As part of chapter 4, we have generated OMV constructs expressing OspA and immunized mice with meningococcal OMVs carrying OspA from B. burgdorferi ss strain BPN. We subsequently challenged the immunized mice with a subcutaneous injection of B. burgdorferi ss and assessed both the immunogenicity of the OMVs compared to aluminum (AlOH) and the protection against B. burgdorferi ss transmission. We showed reasonable antibody titers against the OspA-OMV construct, although lower compared to the antibody titers against recombinant OspA. More importantly, with regard to protection against B. burgdorferi ss transmission, we demonstrated that both the OspA-OMV construct as well as recombinant OspA with separate OMV as adjuvant, provided partial, yet significant protection. Our findings reveal that OMV-based vaccines expressing B. burgdorferi sl (lipo)proteins are a promising vaccination method protecting against B. burgdorferi sl infection and could be considered as a potential vaccination strategy in humans.\n\nIn chapter 5 we focus on a recently described B. burgdorferi sl protein, BB0405, which is a surface exposed protein that is highly conserved across different B. burgdorferi sl species. Therefore, this encompassed an interesting vaccine candidate potentially inducing cross-species protection. To investigate this further, we determined whether vaccination of mice with recombinant BB0405 or with bb0405 DNA tattoo vaccination from B. burgdorferi ss BPN protected against a challenge with B. afzelii CB4P infected Ixodes ricinus nymphs. We observed a high IgG antibody response when the recombinant BB0405 vaccine was applied, but not when the bb0405 DNA tattoo vaccine was used. Surprisingly, neither of the vaccines provided cross-species protection in the mice upon challenge of 8 B. afzelii strain CB4P-infected ticks. Next, we investigated the expression of BB0405 in the different B. burgdorferi sl species and we demonstrated a significant downregulation of BB0405 in the B. afzelii CB4P spirochetes at 37\u00b0C compared to 33\u00b0C. This was not observed for B. burgdorferi ss BPN. These observations could potentially explain the lack of protection in the mice vaccinated with the recombinant BB0405 vaccine, despite the high specific IgG antibody titers.\n\nIn Chapter 6 we used label-free quantitative proteomics to identify and select tick salivary gland proteins from I. ricinus that are differentially expressed during tick feeding and in response to B. afzelii CB4P infection. We have been able to identify 870 I. ricinus proteins from which 68 were upregulated upon 24 hour feeding in B. afzelii CB4P infected I. ricinus ticks. Next, we selected 7 tick salivary gland proteins, which we were able to technically and biologically validate, and we recombinantly expressed these in E. coli. We vaccinated both guinea pigs and mice with a cocktail of the 7 recombinant proteins and subsequently challenged them with I. ricinus ticks. We were able to show significant reduction in post-engorgement weights of I. ricinus ticks in both tick challenge models. Future research should investigate which of the tick proteins is responsible for the observed findings and focus on vaccine optimization. It would also be of interest to determine whether combining a selection of our newly identified antigens with other antigens from either tick or other tick-borne pathogens could protect against transmission of B. burgdorferi sl and other tick-borne diseases.\n\nThe last chapter of this thesis, the general discussion, reflects on the different vaccination strategies and vaccination candidates described in the previous chapters and puts our findings in broader perspective. We have shown that it remains a challenge to identify that one candidate, or a combination of candidates, that would prevent Lyme borreliosis and ideally also impairs tick feeding and transmission of other tick-borne diseases. Newer sophisticated techniques such as transcriptomics and proteomics proved to be instrumental to help identify potential vaccine candidates. However, more research is needed delineating the mechanisms by which these tick or B. burgdorferi sl proteins affect the intricate tick-host-pathogen interactions at the tick-bite site. Regardless, based on the findings described in this thesis, one could speculate that applying vaccination platforms that allow for combining antigens from both B. burgdorferi sl and the tick vector, constitute a promising approach in the quest for a broadly protective and efficacious vaccine to prevent Lyme borreliosis.","auteur":"Michelle Klouwens","auteur_slug":"michelle-klouwens","publicatiedatum":"6 april 2023","taal":"NL","url_flipbook":"https:\/\/ebook.proefschriftmaken.nl\/ebook\/michelleklouwens?iframe=true","url_download_pdf":"","url_epub":"","ordernummer":"FTP-202604080904","isbn":"978-94-6469-239-6","doi_nummer":"","naam_universiteit":"Universiteit van Amsterdam","afbeeldingen":13263,"naam_student:":"","binnenwerk":"","universiteit":"Universiteit van Amsterdam","cover":"","afwerking":"","cover_afwerking":"","design":""},"_links":{"self":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/9505","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio"}],"about":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/types\/us_portfolio"}],"author":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/comments?post=9505"}],"version-history":[{"count":1,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/9505\/revisions"}],"predecessor-version":[{"id":9508,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/9505\/revisions\/9508"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media\/13263"}],"wp:attachment":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media?parent=9505"}],"wp:term":[{"taxonomy":"us_portfolio_category","embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio_category?post=9505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}