Infection Models
Immortalised cell lines are frequently used in infection research, but their applications are restricted particularly when immune responses of humans or animals to a viral infection are investigated.
The immune response is a complex interaction of various components of the immune system, and up to now it cannot be mimicked completely in cell culture systems. Furthermore, the diversity of cell types gets lost in immortalised cell lines and changes in expression patterns of cellular proteins may occur. Cells of the respiratory tract are particularly subject to the loss of typical characteristics, such as the production of mucus or the presence of cilia. Thus, cell cultures cannot or do not sufficiently reflect the situation of organs in vivo. For more in-depth analyses of interactions between pathogens and hosts, it is inevitable to use models that ideally copy the situation within the living organism.
The main aim of our platform is to establish and to continuously develop various models while steadily considering the 4R principles (replacement, reduction, refinement, responsibility). Our models include both in vivo models in non-human primates (NHP) and ex vivo models using primary cell cultures.
NHP models
The close evolutionary relationship between humans and primates makes them suitable models to examine and to comprehend different aspects of infectious diseases in humans. This implies transmission paths, pathogenesis and therapeutic approaches such as the use of monoclonal antibodies against specific viral infections or the testing of new immunization strategies and vaccines for antiviral prophylaxis.The choice of primate models depends on the specific issue and the virus to be analysed. Rhesus monkeys, long-tailed macaques and marmosets are among the most frequently used animal models. Our facilities enable us to pursue and evaluate infection trials with biological and genetically modified pathogens of biosafety levels ranging from 1 to 3 in accordance with the effective Biological Agents Ordinance, the Specified Animal Pathogens Ordinance and the Genetic Engineering Act.Our already established models in rhesus and long-tailed macaques include for example an SIV/HIV (simian/human immunodeficiency virus) primate model to analyze HIV, models to investigate novel therapeutical options with adeno-associated viruses (AAV) as well as infection models on various respiratory viruses, such as the respiratory syncytial virus (RSV), influenza A viruses (FluA) and SARS-CoV-2. Furthermore, a marmoset model has been established for research on the Kaposi sarcoma.
Routine sampling is mainly done via collection of blood samples, swabs samples, urine samples, bronchoalveolar lavage fluid and, depending on the circumstances and the pathogen, via bone marrow puncture, collection of cerebrospinal fluid and lymph node biopsies under injection anaesthesia. Major surgical interventions are done by inhalation anaesthesia and continuous anaesthesia monitoring.
Primary cell cultures
In certain cases, primary cell cultures are an alternative in terms of animal models and contribute to the reduction of the number of experimental animals according to the 4R principle. Our focus lays on primary cultures of the respiratory tract. Especially precision-cut lung slices (PCLS) represent an ex vivo model which enables us to examine the susceptibility of lung cells to certain respiratory pathogens, to identify target cells and to test antiviral agents in a setting which reflects lifelike lung conditions.
Selected publications:
Färber I, Krüger J, Rocha C, Armando F, von Köckritz-Blickwede M, Pöhlmann S, Braun A, Baumgärtner W, Runft S, Krüger N. „Investigations on SARS-CoV-2 Susceptibility of Domestic and Wild Animals Using Primary Cell Culture Models Derived from the Upper and Lower Respiratory Tract.” Viruses. 2022 Apr 16;14(4):828. doi: 10.3390/v14040828.
Krüger N, Rocha C, Runft S, Krüger J, Färber I, Armando F, Leitzen E, Brogden G, Gerold G, Pöhlmann S, Hoffmann M, Baumgärtner W. „The Upper Respiratory Tract of Felids Is Highly Susceptible to SARS-CoV-2 Infection.” Int J Mol Sci. 2021 Sep 30;22(19):10636. doi: 10.3390/ijms221910636.
Hempel T, Elez K, Krüger N, Raich L, Shrimp JH, Danov O, Jonigk D, Braun A, Shen M, Hall MD, Pöhlmann S, Hoffmann M, Noé F. „Synergistic inhibition of SARS-CoV-2 cell entry by otamixaban and covalent protease inhibitors: pre-clinical assessment of pharmacological and molecular properties.” Chem Sci. 2021 Aug 26;12(38):12600-12609. doi: 10.1039/d1sc01494c.