Overview of research projects

Funding: Hirsch foundation, 50.000 EUR

Project Details:
Decellularized heart valve tissues can be used to replace a malfunctioning heart valve. This option is particularly suitable for young patients, because decellularized tissues have regeneration potential. We have pioneered in developing methods for dry preservation of mammalian cells and tissues and demonstrated that this can be done using disaccharides such as sucrose or trehalose which can be found at high concentrations in anhydrobiotic organisms that naturally survive drying. Drying of decellularized heart valves may alter the properties of the extracellular matrix and impair their in vivo efficacy. The central aim of this project is to test if sucrose can be used for dry preservation of heart valves so that they can be safely used for transplantation. We already established methods to freeze-dry heart valves, but their storage stability needs to be demonstrated. In this project we plan to evaluate if vacuum-drying, which lacks a damaging freezing step, can be used as an alternative drying method. The second objective is to study the effects of (freeze-)drying on scaffold structure, and matrix biomolecules directly after drying as well during storage under normal (4°C or room temperate) and accelerated aging (37°C/high relative humidity) storage conditions. The general tissue architecture will be studied on hematoxylin-eosin stained tissue sections, whereas Fourier transform infrared spectroscopy (FTIR) will be used to obtain spectral fingerprints of tissues during storage. For the latter principal component analysis of the spectra will be used to evaluate tissue modifications during storage. Furthermore, accumulation of oxidative damage will be determined. We postulate that overall tissue structural appearance, and therewith functionality, are compromised by ice crystals, and that this can be minimized by reducing the tissue water content prior to freezing, or to avoid ice formation by using vacuum drying.

Funding: MWK über Technischen Informationsbibliothek (TIB), 89.827 EUR

Project Details:
Initiierung einre OER-Sammlung zum Thema "Tierschutz und Ethik"

Funding: Niedersächsisches Ministerium für Ernährung, Landwirtschaft und Verbraucherschutz, 166.732 EUR

Project Details:
Der Verantwortungsraum von Berater/Innen wird bestimmt und Empfehlungen an die Hand gegeben, wie eine verantwortungsbewusste Beratung konkret umgesetzt werden kann. Es werden Konzept und Material für Fortbildungsangebote entwickelt, die zum einen Verantwortung von Berater/innen verdeutlichen und zum anderen auch die tierethischen Aspekte in der Beratung vermitteln.

Funding: Niedersächsisches Ministerium für Ernährung, Landwirtschaft und Verbraucherschutz, 166.732 EUR

Project Details:
The area of responsibility of advisors is determined and recommendations are given on how responsible advice can be implemented in practice. A concept and material for further training courses will be developed which, on the one hand, clarify the responsibility of advisors and, on the other hand, also convey the animal ethical aspects of advice.

Results:

The provision of advice to farms plays an important role in establishing animal welfare measures in livestock farming. One of the aims of the project was to identify the interrelationships of responsibility in advisory services. To this end, the areas of responsibility were first determined, e.g. in the design of the advisory process or in the decision and implementation of the advisory content.

As values can influence the guidance process, it is always important for guidance practitioners to be clear about their values, whereby it is also important to differentiate between their own values and those of the employer. Critical reflection is an important tool for this. Significant values were identified during the project.

A framework was also created with regard to animal welfare/animal protection, which shows the responsibility of advisors. In the course of this, it was possible to outline the approaches that animal welfare advice must pursue in order to meet the requirements for good advice and to be able to provide sustainable approaches for greater animal welfare.

When discussing animal welfare/animal protection, there are always conflicts of objectives.

It is very important for the success of an advisory service that these conflicting goals are identified.A decision-making cascade developed in the project is intended to provide a remedy here, which is intended to encourage reflection throughout the advisory activity.

The project developed a training program that has already been successfully tested in practice. It dealt with the thematic blocks entitled "Consultancy in the knowledge system of agriculture", "Fundamentals of animal ethics", "Responsibility and scope for responsibility in consultancy", "Values and requirements for ethically "good" consultancy", "Animal welfare and animal protection in consultancy" and "Conflicting objectives and the decision-making cascade".

The extremely large number of advisors from both official and private advisory services who attended the event showed the great interest in this topic in the run-up to the event and thus also the need to address it among advisors.

The project has thus succeeded in defining the area of responsibility of counselors and providing them with recommendations on how responsible counseling can be implemented. The training program clarifies the responsibility of advisors and highlights the importance of advice for animal welfare and animal protection.

Funding: Pfizer, 54.000 EUR

Project Details:
Tick-borne encephalitis (TBE) is considered as one of the most important viral tick-borne diseases affecting humans. The disease may cause death or permanent disability due to severe neurological damage. TBE thus represents a considerable public health burden. In recent years, a considerable geographic expansion of TBE has been noted in Germany with the consequence the National Institute of Public Health (Robert-Koch-Institut) declared district in the Northern Germ federal state Lower Saxony as official risk area in the beginning of 2019. However, the usually very small areas of TBE virus circulation (so called natural foci) are still mostly unknown in Northern Germany. This study aims to identify the locations of TBE transmission foci (i.e. the presence of TBE-positive ticks) in Lower Saxony, Northern Germany, by following up on the movement patterns and possible sources of tick exposure of TBE patients. Detection of TBE virus occurrence in Northern Germany will help to prevent clinical cases of disease as it can be expected that public awareness about TBE foci will lead to avoidance of known hot spot areas and increase the people´s willingness to vaccinate.

Results:

Topp, A.-K., Springer, A., Dobler, G., Bestehorn-Willmann, M., Monazahian, M., Strube, C. (2022) New and confirmed foci of tick-borne encephalitis virus (TEBV) in Northern Germany determined by TEBV detection in ticks. Pathogens 11, 126

https://www.mdpi.com/2076-0817/11/2/126

Cooperation Partners:

Dr. M. Monazahian, Niedersächsisches Landesgesundheitsamt, Hannover

Prof. Dr. Gerhard Dobler, Nationales Konsiliarlabor für FSME, München

Funding: Karl-Eibl-Stiftung (Form: Stipendium: 900?/Mo für Doktorand), 18.900 EUR

Project Details:
The aim of the first part of the dissertation project is to establish an innovative technology as a method of separating bull semen. The basis of this technology is the use of microfluidic chips. The second part of the project is to use this technology in genetically valuable breeding bulls whose ejaculates contain less than 70% forward-motility sperm. This technology could also be used to improve the quality of sex sorting of spermcells.

Results:

In this work we used samples with artificially induced damage for establishing protocols for flow cytometric analysis of sperm viability, as well as computer assisted analysis of sperm motility patterns. Moreover, we found that samples previously enriched with damaged sperm were especially useful for testing the effectiveness of different sperm selection procedures.

 

The major aim of this work was to evaluate how microfluidic chips perform in selecting high quality sperm, i.e., in comparison to other techniques such as swim-up and percoll density gradient centrifugation. In addition, we planned to test if sperm selected, using microfluidic chips exhibit better motility behavior, increased fertilization capacity in vitro, and wanted to evaluate the performance with the flow cytometric X/Y-sperm sorting.

 

Both, freshly diluted and cryopreserved sperm were tested also taking into account the variation among individuals. We determined that when using microfluidic sorting and swim-up methods, sperm recovery was low, however, sperm were of superior quality. Sperm recovery was higher after using percoll density gradient centrifugation, but this coincided with the presence of increased numbers of membrane damaged and motile sperm. In addition, the presence of a relatively high ratio of motile sperm in high quality sperm samples exhibited characteristic kinematic parameters including increased movement velocity and linearity; which was maintained when specimens were investigated in viscous media, mimicking oviductal fluid. In our hands, when compared with ordinary processing, remained that the increased sperm quality after microfluidic selection did not result an increased in vitro embryo production. Nonetheless, performing microfluidic sperm selection prior to flow cytometric sorting of X/Y-sperm appeared beneficial; since this improved initial sperm quality to required levels, reduced contents of debris and dead sperm during FACS sorting, and enabled to significantly improve sorting speed and the correctly oriented X-chromosome bearing sperm numbers in the population.

 

In conclusion, the use of microfluidic chips has great potential in reproductive medicine and veterinary assisted reproduction technologies. This is not only beneficial for any easier selection and enrichment of high quality sperm samples, which are more likely to fertilize an oocyte, but as a processing step, also for fulfilling the requirements needed for successful flow cytometric sorting of X/Y chromosome bearing sperm.

The use of microfluidic chips has great potential in reproductive medicine and veterinary assisted reproduction technologies. This is not only beneficial for any easier selection and enrichment of high quality sperm samples, which are more likely to fertilize an oocyte, but as a processing step, also for fulfilling the requirements needed for successful flow cytometric sorting of X/Y chromosome bearing sperm.

https://elib.tiho-hannover.de/receive/tiho_mods_00012249

Cooperation Partners:

Calisici, Oguz, Phytobiotics GmbH

Alkabes, Stephane, Masterrind GmbH Verden

Funding: Bundesministerium für Bildung und Forschung, 124.297 EUR

Project Details:
Das Gesamtziel des Vorhabens wird in der ebenfalls vorliegenden Verbundvorhabenbeschreibung von TBENAGER ausführlich dargestellt. In diesem Teilprojekt (TP6) soll das Infektionsmodell mit Zecken aus FSME Naturherden und Kontrollgebieten und verschiedenen FSME Virusisolaten etabliert werden. Das FSME Virus zirkuliert in der Natur in einem enzootische Übertragungszyklus zwischen Ixodes ricinus Zecken und verschiedenen Wirtstieren. Ixodes ricinus Zecken wie auch verschiedenen Wirtstieren sind Zentral-und Mitteleuropa nahezu flächendeckend verbreitet. Im Gegensatz dazu weißt die Verbreitung des FSME Virus gerade in Deutschland eine extrem fokale Herde auf. Zumeist wir das Virus in sehr begrenzenden Gebieten nachgewiesen wohingegen in umliegende Bereiche zwar Zecken jedoch kein FSME Virus gefunden wird. Daher stellt sich die Frage welche Faktoren die Verbreitung des FSME Virus begrenzen. Zur Beantwortung dieser Frage soll diesem Projekt ein Infektionsmodel erstellt werden welches Zecken aus verschiedenen FSME Naturherden und Rötelmäuse nutzt um die Interaktion von FSME Virusstämmen mit den jeweiligen Zeckenpopulationen unter Miteinbeziehung des natürlichen Reservoir Wirtes untersucht

Cooperation Partners:

PD Dr. Gerhard Dobler, Institut für Mikrobiologie der Bundeswehr, München;Dr. Merle Böhmer, Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, Oberschleißheim; Dr. Christiane Wagner-Wiening, Landesgesundheitsamt, Stuttgart; Dr. Wiebke Hellenbrand, Robert-Koch-Institut, Berlin; Prof. Ute Mackenstedt, Institut für Zoologie, Universität Hohenheim; Prof. Martin Pfeffer, Institut für Tierhygiene und Öffentliches Veterinärwesen, Leipzig; Prof. Ralph Kühn, Lehrstuhl Zoologie, Technische Universität München, Weihenstephan; Prof. Martin Beer, Institut für Virusdiagnostik, Insel Riems; Prof. Andrea Kröger, Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Magdeburg;

Funding: MWK, 4.000.000 EUR

Project Details:
Das im letzten Jahr neu entdeckte Coronavirus SARS-CoV-2 (Betacoronavirus, Coronavirdae) verursacht
aktuell eine globale Pandemie. Die Todesrate wird aufgrund aktueller Berechnungen zwischen 0,25 %
und 12% geschätzt (Wilson et al. 2020, Mizumoto et al. 2020). Bisher gibt es keine Prophylaxe oder
Therapie gegen die durch SARS-CoV-2 verursachte Erkrankung "COVID-19". Die Herkunft von SARS-CoV2 ist bisher unbekannt, allerdings werden Fledermäuse und Schuppentiere aktuell als Überträger
diskutiert (Tsan-Yuk Lam et al. 2020). Daher sind experimentelle Tiermodelle eine effiziente, sichere,
schnelle und somit unabdingbare Basis für die Entwicklung und Testung von präventiven und
therapeutischen Maßnahmen gegen SARS-CoV-2-Infektionen beim Menschen.
Frettchen gelten als geeignete Testmodelle für die Erforschung der Pathogenese und Entwicklung von
Impfstoffen gegen das 2003 entdeckte SARS-CoV-1. SARS-CoV-1 und -2 nutzen über das virale spike (S)
Protein den Wirtszellrezeptor ACE2 (Hoffmann et al. 2020), um Wirtszellen zu infizieren. Daher werden
Frettchen bereits für die Erforschung von SARS-CoV-2 eingesetzt (Callaway 2020). Phylogenetische
Analysen des ACE2 Rezeptors (Abb. 1, Anhang 1) zeigen, dass eine enge genetische Verwandtschaft
zwischen dem ACE2 Rezeptor von Menschen und Kaninchen vorliegt, und sich somit Frettchen und
insbesondere auch Kaninchen deutlich besser für die Forschung zum SARS-CoV-2 eignen als z.B. das
häufig eingesetzte Mausmodell. Zusätzlich werden Hamster als geeignetes Modell angesehen (Cohen,
2020). Darüber hinaus sind nicht-menschliche Primaten (NHP) für die Testung von Impfstoffen von
zentraler Bedeutung, da sie die Immunantwort des Menschen am besten widerspiegeln. Ausgewählte
Wirkstoffe und Impfstoffe, die sich als geeignet und sicher in den oben genannten Tiermodellen
erwiesen haben, sollen zur abschließenden Bewertung in NHP-Modellen getestet werden.
Beim Testen von Impfstoffkandidaten und Antikörperpräparaten in Humanstudien besteht wie bei
anderen Coronaviren das Risiko einer erhöhten Anfälligkeit für SARS-CoV-2-Infektionen, was bei einer
natürlichen Infektion zu einer schwerwiegenderen Erkrankung führt. Dies kann durch eine
antikörperabhängige Verstärkung, durch verzerrte Immunantworten (z.B. durch T-Zellen) oder durch
eine Kombination solcher Mechanismen verursacht werden. Hinweise für eine solche Verstärkung
wurden bereits für Impfstoffe gegen SARS und MERS erhalten und es muss sichergestellt werden, dass
eine vergleichbare Problematik nicht bei einem Impfstoff auftritt, der zur Bekämpfung der COVID-19-
Pandemie eingesetzt wird. Daher ist es von größter Bedeutung, Tiermodelle zu etablieren, die den normale und den therapeutisch
verbesserten Krankheitsverlauf von COVID-19 für eine optimale Risikominimierung nachbilden. Daher
sollen hier schnellstmöglich ab sofort experimentelle Testmodelle im Frettchen, Kaninchen und Hamster
in den BSL-3-Laboren und auch Tierstallungen am Research Center for Emerging Infections and Zoonoses
(RIZ), sowie mit nicht-menschliche Primaten (NHP) am Primatenzentrum in Göttingen etabliert werden,
um diese Modelle für die unmittelbare Testung von neuen antiviralen Strategien und
Impfstoffentwicklungen einzusetzen. Für die Durchführung dieser Tierversuche ist ein höchstmöglicher
Standard im Sinne des Tierschutzes und der Biosicherheit erforderlich. Die beteiligten Einrichtungen
verfügen über die fachliche Expertise und auch institutionelle Voraussetzung mit modernster
Gebäudetechnologien, um diesen Standards gerecht zu werden. Damit können diese Einrichtungen mit
der Etablierung dieser Tiermodelle eine Plattform für die regionale, aber auch nationale und
internationale Forschung liefern, um schnellstmöglich die Testung von Wirkstoffen und Impfstoffen
umzusetzen.

Funding: EU Kommission (Horizon 2020), 3.034.581 EUR

Funding: BMBF, 46.843 EUR

Project Details:
The aim of the project is to determine the genetic diversity of "tick-borne encephalitis virus" (TBEV; German:
Tick-borne encephalitis (TBE) virus) and the virus-specific T cell response
characterize. The hypothesis applies that TBEV-specific T cell responses with
different phenotypes and different protein specificity for protection or for
Neuropathogenesis of TBEV infections in humans and mice help to substantiate. the
detailed characterization of the T-cell immune response in humans and mice forms the basis for
future research on improved vaccines that more specifically stimulate the immune system and thus
could provide stronger and longer-lasting immunization protection.